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GENERAL DESCRIPTION
The DS26502 is a building-integrated timing-
supply (BITS) clock-recovery element. It also
functions as a basic T1/E1 transceiver. The
receiver portion can recover a clock from T1,
E1, 64kHz composite clock (64KCC), and
6312kHz synchronization timing interfaces. In
T1 and E1 modes, the Synchronization Status
Message (SSM) can also be recovered. The
transmit portion can directly interface to T1, E1,
or 64KCC synchronization interfaces as well as
source the SSM in T1 and E1 modes. The
DS26502 can translate between any of the
supported inbound synchronization clock rates to
any supported outbound rate. A separate output
is provided to source a 6312kHz clock. The
device is controlled through a parallel, serial, or
hardware controller port.
APPLICATIONS
BITS Timing
Rate Conversion
ORDERING INFORMATION
PART TEMP RANGE PIN-PACKAGE
DS26502L 0°C to +70°C 64 LQFP
DS26502LN -40°C to +85°C 64 LQFP
FEATURES
G.703 2048kHz Synchronization Interface
Compliant
G.703 64kHz Centralized (Option A) and
Codirectional Timing Interface Compliant
G.703 Appendix II 64kHz and 6312kHz
Japanese Synchronization Interface
Compliant
Interfaces to Standard T1/J1 (1.544MHz) and
E1 (2.048MHz)
Interface to CMI-Coded T1/J1 and E1
Short- and Long-Haul Line Interface
Transmit and Receive T1 and E1 SSM
Messages with Message Validation
T1/E1 Jitter Attenuator with Bypass Mode
Fully Independent Transmit and Receive
Functionality
Internal Software-Selectable Receive- and
Transmit-Side Termination for
75Ω/100Ω/110Ω/120Ω T1, E1, and
Composite Clock Interfaces
Monitor Mode for Bridging Applications
Accepts 16.384MHz, 12.8MHz, 8.192MHz,
4.096MHz, 2.048MHz, or 1.544MHz Master
Clock
64kHz, 8kHz, and 400Hz Outputs in
Composite Clock Mode
8-Bit Parallel Control Port, Multiplexed or
Nonmultiplexed, Intel or Motorola
Serial (SPI) Control Port
Hardware Contr-ol Mode
Provides LOS, AIS, and LOF Indications
Through Hardware Output Pins
Fast Transmitter-Output Disable Through
Device Pin for Protection Switching
IEEE 1149.1 JTAG Boundary Scan
3.3V Supply with 5V Tolerant Inputs and
Outputs
DS26502
T1/E1/J1/64KCC BITS Element
www.maxim-ic.com
DESIGN KIT AVAILABLE
DS26502 T1/E1/J1/64KCC BITS Element
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TABLE OF CONTENTS
1. FEATURES.......................................................................................................................7
1.1 GENERAL .....................................................................................................................................7
1.2 LINE INTERFACE ...........................................................................................................................7
1.3 JITTER ATTENUATOR (T1/E1 MODES ONLY)..................................................................................7
1.4 FRAMER/FORMATTER ...................................................................................................................8
1.5 TEST AND DIAGNOSTICS ...............................................................................................................8
1.6 CONTROL PORT............................................................................................................................8
2. SPECIFICATIONS COMPLIANCE ...................................................................................9
3. BLOCK DIAGRAMS .......................................................................................................11
4. PIN FUNCTION DESCRIPTION .....................................................................................14
4.1 TRANSMIT PLL ...........................................................................................................................14
4.2 TRANSMIT SIDE ..........................................................................................................................14
4.3 RECEIVE SIDE ............................................................................................................................15
4.4 CONTROLLER INTERFACE............................................................................................................16
4.5 JTAG.........................................................................................................................................21
4.6 LINE INTERFACE .........................................................................................................................21
4.7 POWER ......................................................................................................................................22
5. PINOUT...........................................................................................................................23
6. HARDWARE CONTROLLER INTERFACE....................................................................26
6.1 TRANSMIT CLOCK SOURCE .........................................................................................................26
6.2 INTERNAL TERMINATION..............................................................................................................26
6.3 LINE BUILD-OUT .........................................................................................................................27
6.4 RECEIVER OPERATING MODES....................................................................................................27
6.5 TRANSMITTER OPERATING MODES..............................................................................................28
6.6 MCLK PRE-SCALER ...................................................................................................................28
6.7 OTHER HARDWARE CONTROLLER MODE FEATURES ....................................................................29
7. PROCESSOR INTERFACE............................................................................................30
7.1 PARALLEL PORT FUNCTIONAL DESCRIPTION................................................................................30
7.2 SPI SERIAL PORT INTERFACE FUNCTIONAL DESCRIPTION............................................................30
7.2.1 Clock Phase and Polarity..................................................................................................................... 30
7.2.2 Bit Order............................................................................................................................................... 30
7.2.3 Control Byte ......................................................................................................................................... 30
7.2.4 Burst Mode........................................................................................................................................... 30
7.2.5 Register Writes..................................................................................................................................... 31
7.2.6 Register Reads .................................................................................................................................... 31
7.3 REGISTER MAP...........................................................................................................................32
7.3.1 Power-Up Sequence ............................................................................................................................ 34
7.3.2 Test Reset Register ............................................................................................................................. 34
7.3.3 Mode Configuration Register ............................................................................................................... 35
7.4 INTERRUPT HANDLING ................................................................................................................38
7.5 STATUS REGISTERS....................................................................................................................38
7.6 INFORMATION REGISTERS ...........................................................................................................39
7.7 INTERRUPT INFORMATION REGISTERS .........................................................................................39
8. T1 FRAMER/FORMATTER CONTROL REGISTERS ....................................................40
8.1 T1 CONTROL REGISTERS............................................................................................................40
9. E1 FRAMER/FORMATTER CONTROL REGISTERS....................................................46
9.1 E1 CONTROL REGISTERS ...........................................................................................................46
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9.2 E1 INFORMATION REGISTERS......................................................................................................48
10. I/O PIN CONFIGURATION OPTIONS ............................................................................52
11. T1 SYNCHRONIZATION STATUS MESSAGE ..............................................................55
11.1 T1 BIT-ORIENTED CODE (BOC) CONTROLLER ............................................................................55
11.2 TRANSMIT BOC .........................................................................................................................55
11.3 RECEIVE BOC ...........................................................................................................................56
12. E1 SYNCHRONIZATION STATUS MESSAGE ..............................................................64
12.1 SA/SI BIT ACCESS BASED ON CRC4 MULTIFRAME......................................................................64
12.2 ALTERNATE SA/SI BIT ACCESS BASED ON DOUBLE-FRAME .........................................................74
13. LINE INTERFACE UNIT (LIU) ........................................................................................77
13.1 LIU OPERATION ......................................................................................................................... 78
13.2 LIU RECEIVER ...........................................................................................................................78
13.2.1 Receive Level Indicator........................................................................................................................ 78
13.2.2 Receive G.703 Section 13 Synchronization Signal ............................................................................. 79
13.2.3 Monitor Mode ....................................................................................................................................... 79
13.3 LIU TRANSMITTER ..................................................................................................................... 79
13.3.1 Transmit Short-Circuit Detector/Limiter................................................................................................ 80
13.3.2 Transmit Open-Circuit Detector ........................................................................................................... 80
13.3.3 Transmit BPV Error Insertion ............................................................................................................... 80
13.3.4 Transmit G.703 Section 10 Synchronization Signal (E1 Mode)........................................................... 80
13.4 MCLK PRE-SCALER ..................................................................................................................80
13.5 JITTER ATTENUATOR.................................................................................................................. 80
13.6 CMI (CODE MARK INVERSION) OPTION....................................................................................... 81
13.7 LIU CONTROL REGISTERS.......................................................................................................... 82
13.8 RECOMMENDED CIRCUITS .......................................................................................................... 90
14. LOOPBACK CONFIGURATION.....................................................................................95
15. 64KHZ SYNCHRONIZATION INTERFACE....................................................................96
15.1 RECEIVE 64KHZ SYNCHRONIZATION INTERFACE OPERATION....................................................... 96
15.2 TRANSMIT 64KHZ SYNCHRONIZATION INTERFACE OPERATION..................................................... 97
16. 6312KHZ SYNCHRONIZATION INTERFACE................................................................98
16.1 RECEIVE 6312KHZ SYNCHRONIZATION INTERFACE OPERATION................................................... 98
16.2 TRANSMIT 6312KHZ SYNCHRONIZATION INTERFACE OPERATION................................................. 98
17. JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT ...................99
17.1 INSTRUCTION REGISTER........................................................................................................... 103
17.2 TEST REGISTERS .....................................................................................................................104
17.2.1 Boundary Scan Register .................................................................................................................... 104
17.2.2 Bypass Register ................................................................................................................................. 104
17.2.3 Identification Register......................................................................................................................... 104
18. FUNCTIONAL TIMING DIAGRAMS .............................................................................107
18.1 PROCESSOR INTERFACE ...........................................................................................................107
18.1.1 Parallel Port Mode.............................................................................................................................. 107
18.1.2 SPI Serial Port Mode.......................................................................................................................... 107
19. OPERATING PARAMETERS .......................................................................................110
20. AC TIMING PARAMETERS AND DIAGRAMS ............................................................112
20.1 MULTIPLEXED BUS ................................................................................................................... 112
20.2 NONMULTIPLEXED BUS............................................................................................................. 115
20.3 SERIAL BUS .............................................................................................................................118
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20.4 RECEIVE SIDE AC CHARACTERISTICS.......................................................................................120
20.5 TRANSMIT SIDE AC CHARACTERISTICS.....................................................................................122
21. REVISION HISTORY ....................................................................................................124
22. PACKAGE INFORMATION ..........................................................................................125
22.1 64-PIN LQFP (56-G4019-001).................................................................................................125
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LIST OF FIGURES
Figure 3-1. Block Diagram........................................................................................................................11
Figure 3-2. Loopback Mux Diagram (T1/E1 Modes Only) ........................................................................12
Figure 3-3. Transmit PLL Clock Mux Diagram..........................................................................................12
Figure 3-4. Master Clock PLL Diagram ....................................................................................................13
Figure 13-1. Basic Network Connection ...................................................................................................77
Figure 13-2. Typical Monitor Application ..................................................................................................79
Figure 13-3. CMI Coding ..........................................................................................................................81
Figure 13-4. Software-Selected Termination, Metallic Protection.............................................................90
Figure 13-5. Software-Selected Termination, Longitudinal Protection .....................................................91
Figure 13-6. E1 Transmit Pulse Template................................................................................................92
Figure 13-7. T1 Transmit Pulse Template ................................................................................................92
Figure 13-8. Jitter Tolerance (T1 Mode)...................................................................................................93
Figure 13-9. Jitter Tolerance (E1 Mode)...................................................................................................93
Figure 13-10. Jitter Attenuation (T1 Mode)...............................................................................................94
Figure 13-11. Jitter Attenuation (E1 Mode) ..............................................................................................94
Figure 15-1. 64kHz Composite Clock Mode Signal Format......................................................................96
Figure 17-1. JTAG Functional Block Diagram ..........................................................................................99
Figure 17-2. TAP Controller State Diagram............................................................................................102
Figure 18-1. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 0...............................................107
Figure 18-2. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 0...............................................107
Figure 18-3. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 1...............................................107
Figure 18-4. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 1...............................................108
Figure 18-5. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 0...............................................108
Figure 18-6. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 0...............................................108
Figure 18-7. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 1...............................................109
Figure 18-8. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 1...............................................109
Figure 20-1. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 00)...............................................................113
Figure 20-2. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 00)................................................................113
Figure 20-3. Motorola Bus Timing (BTS = 1 / BIS[1:0] = 00)..................................................................114
Figure 20-4. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 01)................................................................116
Figure 20-5. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 01)................................................................116
Figure 20-6. Motorola Bus Read Timing (BTS = 1 / BIS[1:0] = 01) ........................................................117
Figure 20-7. Motorola Bus Write Timing (BTS = 1 / BIS[1:0] = 01).........................................................117
Figure 20-8. SPI Interface Timing Diagram, CPHA = 0, BIS[1:0] = 10 ...................................................119
Figure 20-9. SPI Interface Timing Diagram, CPHA = 1, BIS[1:0] = 10 ...................................................119
Figure 20-10. Receive Timing, T1, E1, 64KCC Mode ............................................................................121
Figure 20-11. Transmit Timing, T1, E1, 64KCC Mode ...........................................................................123
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LIST OF TABLES
Table 2-1. T1-Related Telecommunications Specifications........................................................................9
Table 2-2. E1-Related Telecommunications Specifications .....................................................................10
Table 5-1. LQFP Pinout............................................................................................................................23
Table 6-1. Transmit Clock Source ............................................................................................................26
Table 6-2. Internal Termination ................................................................................................................26
Table 6-3. E1 Line Build-Out ....................................................................................................................27
Table 6-4. T1 Line Build-Out ....................................................................................................................27
Table 6-5. Receive Path Operating Mode ................................................................................................27
Table 6-6.Transmit Path Operating Mode ................................................................................................28
Table 6-7. MCLK Pre-Scaler for T1 Mode ................................................................................................28
Table 6-8. MCLK Pre-Scaler for E1 Mode................................................................................................29
Table 6-9. Other Operational Modes ........................................................................................................29
Table 7-1. Port Mode Select.....................................................................................................................30
Table 7-2. Register Map Sorted By Address ............................................................................................32
Table 8-1. T1 Alarm Criteria .....................................................................................................................45
Table 9-1. E1 Sync/Resync Criteria .........................................................................................................47
Table 9-2. E1 Alarm Criteria .....................................................................................................................49
Table 10-1. TS_8K_4 Pin Functions.........................................................................................................53
Table 10-2. RLOF_CCE Pin Functions ....................................................................................................53
Table 11-1. T1 SSM Messages ................................................................................................................55
Table 12-1. E1 SSM Messages................................................................................................................64
Table 13-1. Component List (Software-Selected Termination, Metallic Protection) .................................90
Table 13-2. Component List (Software-Selected Termination, Longitudinal Protection)..........................91
Table 15-1. Specification of 64kHz Clock Signal at Input Port .................................................................96
Table 15-2. Specification of 64kHz Clock Signal at Output Port..............................................................97
Table 16-1. Specification of 6312kHz Clock Signal at Input Port ............................................................98
Table 16-2. Specification of 6312kHz Clock Signal at Output Port...........................................................98
Table 17-1. Instruction Codes for IEEE 1149.1 Architecture..................................................................103
Table 17-2. ID Code Structure................................................................................................................104
Table 17-3. Device ID Codes .................................................................................................................104
Table 17-4. Boundary Scan Control Bits ................................................................................................105
Table 19-1. Thermal Characteristics ......................................................................................................110
Table 19-2. Theta-JA (θJA) vs. Airflow.....................................................................................................110
Table 19-3. Recommended DC Operating Conditions ...........................................................................110
Table 19-4. Capacitance ........................................................................................................................110
Table 19-5. DC Characteristics ..............................................................................................................111
Table 20-1. AC Characteristics, Multiplexed Parallel Port......................................................................112
Table 20-2. AC Characteristics, Non-Mux Parallel Port..........................................................................115
Table 20-3. AC Characteristics, Serial Bus ............................................................................................118
Table 20-4. Receive Side AC Characteristics.........................................................................................120
Table 20-5. Transmit Side AC Characteristics........................................................................................122
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1. FEATURES
1.1 General
64-pin, 10mm x 10mm LQFP package
3.3V supply with 5V-tolerant inputs and outputs
Evaluation kits
IEEE 1149.1 JTAG Boundary Scan
Driver source code available from the factory
1.2 Line Interface
Requires a single master clock (MCLK) for E1, T1, or J1 operation. Master clock can be
2.048MHz, 4.096MHz, 8.192MHz, 12.8MHz (available in CPU interface mode only), or
16.384MHz. Option to use 1.544MHz, 3.088MHz, 6.176MHz, or 12.5552MHz for T1-only
operation.
Fully software configurable
Short- and long-haul applications
Automatic receive sensitivity adjustments
Ranges include 0dB to -43dB or 0dB to -12dB for E1 applications; 0dB to -36dB or 0dB to -15dB
for T1 applications
Receive level indication in 2.5dB steps from -42.5dB to -2.5dB
Internal receive termination option for 75Ω, 100Ω, 110Ω, and 120Ω lines
Monitor application gain settings of 20dB, 26dB, and 32dB
G.703 receive-synchronization signal mode
Flexible transmit-waveform generation
T1 DSX-1 line build-outs
E1 waveforms include G.703 waveshapes for both 75Ω coax and 120Ω twisted cables
AIS generation independent of loopbacks
Alternating ones and zeros generation
Square-wave output
Open-drain output option
Transmitter power-down
Transmitter 50mA short-circuit limiter with exceeded indication of current limit
Transmit open-circuit-detected indication
1.3 Jitter Attenuator (T1/E1 Modes Only)
32-bit or 128-bit crystal-less jitter attenuator
Requires only a 2.048MHz master clock for both E1 and T1 operation with the option to use
1.544MHz for T1 operation
Can be placed in either the receive or transmit path or disabled
Limit trip indication
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1.4 Framer/Formatter
Full receive and transmit path transparency
T1 framing formats include D4 and ESF
E1 framing formats include FAS and CRC4
Detailed alarm and status reporting with optional interrupt support
RLOF, RLOS, and RAIS alarms interrupt on change of state
Japanese J1 support includes:
− Ability to calculate and check CRC6 according to the Japanese standard
− Ability to generate yellow alarm according to the Japanese standard
1.5 Test and Diagnostics
Remote and Local Loopback
1.6 Control Port
8-bit parallel or serial control port
Multiplexed or nonmultiplexed buses
Intel or Motorola formats
Supports polled or interrupt-driven environments
Software access to device ID and silicon revision
Software-reset supported with automatic clear on power-up
Hardware controller port
Hardware reset pin
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2. SPECIFICATIONS COMPLIANCE
The DS26502 meets all applicable sections of the latest telecommunications specifications including
those listed in the following tables.
Table 2-1. T1-Related Telecommunications Specifications
ANSI T1.102: Digital Hierarchy Electrical Interface
ANSI T1.231: Digital Hierarchy–Layer 1 in Service Performance Monitoring
ANSI T1.403: Network and Customer Installation Interface–DS1 Electrical Interface
TR62411
(ANSI) “Digital Hierarchy–Electrical Interfaces”
(ANSI) “Digital Hierarchy–Formats Specification”
(ANSI) “Digital Hierarchy–Layer 1 In-Service Digital Transmission Performance Monitoring”
(ANSI) “Network and Customer Installation Interfaces – DS1 Electrical Interface”
(AT&T) “Requirements for Interfacing Digital Terminal Equipment to Services Employing the Extended
Super frame Format”
(AT&T) “High Capacity Digital Service Channel Interface Specification”
(TTC) “Frame Structures on Primary and Secondary Hierarchical Digital Interfaces”
(TTC) “ISDN Primary Rate User-Network Interface Layer 1 Specification”
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Table 2-2. E1-Related Telecommunications Specifications
ITUT G.703 Physical/Electrical Characteristics of G.703 Hierarchical Digital Interfaces
ITUT G.736 Characteristics of Synchronous Digital Multiplex Equipment operating at 2048kbps
ITUT G.742 Second-Order Digital Multiplex Equipment Operating at 8448kbps
ITUT G.772
ITUT G.775
ITUT G.823 The control of jitter and wander within digital networks, which are based on 2.048kbps
hierarchy
ETSI 300 233
(ITU) “Synchronous Frame Structures used at 1544, 6312k, 2048, 8488, and 44,736kbps Hierarchical
Levels”
(ITU) “Frame Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to Basic Frame
Structures Defined in Recommendation G.704”
(ITU) “Characteristics of primary PCM Multiplex Equipment Operating at 2048kbps”
(ITU) Characteristics of a synchronous digital multiplex equipment operating at 2048kbps”
(ITU) “Loss Of Signal (LOS) and Alarm Indication Signal (AIS) Defect Detection and Clearance
Criteria”
(ITU) “The Control of Jitter and Wander Within Digital Networks Which are Based on the 2048kbps
Hierarchy”
(ITU) “Primary Rate User-Network Interface – Layer 1 Specification”
(ITU) “Error Performance Measuring Equipment Operating at the Primary Rate and Above”
(ITU) “In-service code violation monitors for digital systems”
(ETSI) “Integrated Services Digital Network (ISDN); Primary rate User-Network Interface (UNI); Part
1/ Layer 1 specification”
(ETSI) “Transmission and multiplexing; Physical/electrical characteristics of hierarchical digital
interfaces for equipment using the 2048kbps-based plesiochronous or synchronous digital hierarchies”
(ETSI) “Integrated Services Digital Network (ISDN); Access digital section for ISDN primary rate”
(ETSI) “Integrated Services Digital Network (ISDN); Attachment requirements for terminal equipment
to connect to an ISDN using ISDN primary rate access”
(ETSI) “Business Telecommunications (BT); Open Network Provision (ONP) technical requirements;
2048lkbps digital unstructured leased lines (D2048U) attachment requirements for terminal equipment
interface”
(ETSI) “Business Telecommunications (BTC); 2048kbps digital structured leased lines (D2048S);
Attachment requirements for terminal equipment interface”
(ITU) “Synchronous Frame Structures used at 1544, 6312, 2048, 8488, and 44,736kbps Hierarchical
Levels”
(ITU) “Frame Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to Basic Frame
Structures Defined in Recommendation G.704”
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3. BLOCK DIAGRAMS
Figure 3-1. Block Diagram
RX
LIU
RX
LIU T1/E1 SSM
FRAMER
64KCC
DECODER
CLOCK
- DATA
TX
LIU
T1/E1 SSM
FORMATTER
64KCC
CODER
TX PLL
CLOCK
MUX
L
O
C
A
L
L
O
O
P
B
A
C
K
M
U
X
PARALLEL/SERIAL CPU I/F
HARDWARE CONTROLLER
RCLK
LOF_CCE
RSER
RS_8K
400HZ
PLL_OUT
TCLK
TSER
TS_8K_4
+ DATA
RTIP
RRING
RLOS
RAIS
TTIP
TRING
THZE
TPOSO
TNEGO
JITTER
ATTENUATOR
CAN BE
ASSIGNED TO
RECEIVE OR
TRANSMIT PATH
OR DISABLED
MASTER CLOCK
MCLK
JTAG PORT TSTRST
TCLKO
TX CLOCK
- DATA
+ DATA
JA
ENABLED
AND IN RX
PATH
JA
ENABLED
AND IN TX
PATH
DS26502
JTAG PORTJTAG PORTJTAG PORT
JTDOJTDIJTCLKJTMS JTRST BIS1 BIS0
JA
ENABLED
AND IN RX
PATH
R
E
M
O
T
E
L
O
O
P
B
A
C
K
M
U
X
PARALLEL,
SERIAL, OR
HARDWARE
CONTROLLER
JA CLOCK
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Figure 3-2. Loopback Mux Diagram (T1/E1 Modes Only)
Figure 3-3. Transmit PLL Clock Mux Diagram
TX PLL
OUTPUT = 1.544MHz,
2.048MHz, 64kHz,
6.312MHz
JA CLOCK
RECOVERED CLOCK
PLL_OUT PIN
TX CLOCK
TCLK PIN
TPCR.2
TPCR.0
(TCSS0)
TPCR.1
(TCSS1)
TPCR.5
IN
SEL
OUT
SEL
TPCR.3
TPCR.4
TPCR.6
TPCR.7
(HARDWARE MODE PIN NAME)
FROM RX
LIU
TO TX
LIU
CLOCK
+ DATA
- DATA
CLOCK
+ DATA
- DATA
TO RX
FRAMER
FROM TX
FORMATTER
RCLK
+ DATA
- DATA
TX CLOCK
+ DATA
- DATA
REMOTE
LOOPBACK
(LBCR.4)
LOCAL
LOOPBACK
(LBCR.3)
JITTER
ATTENUATOR
ENABLED AND
IN RX PATH
JITTER
ATTENUATOR
ENABLED AND
IN TX PATH
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Figure 3-4. Master Clock PLL Diagram
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4. PIN FUNCTION DESCRIPTION
4.1 Transmit PLL
NAME TYPE FUNCTION
PLL_OUT O
Transmit PLL Output. This pin can be selected to output the 1544kHz,
2048kHz, 64kHz, or 6312kHz output from the internal TX PLL or the internal
signal, TX CLOCK. See Figure 3-3 and Figure 3-4.
TCLK I
Transmit Clock Input. A 64kHz, 1.544MHz, 2.048MHz, or 6312kHz
primary clock. May be selected by the TX PLL mux to either directly drive
the transmit section or be converted to one of the other rates prior to driving
the transmit section. See Figure 3-3 and Figure 3-4.
4.2 Transmit Side
NAME TYPE FUNCTION
TSER I
Transmit Serial Data. Source of transmit data sampled on the falling edge of
TX CLOCK (an internal signal). See Figure 3-1, Figure 3-3, and the transmit
timing diagram (Figure 20-11).
TS_8K_4 I/O
TSYNC, 8kHz Sync, 400Hz Sync
T1/E1 Mode: In input mode, this pin is sampled on the falling edge of TX
CLOCK (an internal signal) and a pulse at this pin will establish either frame
or multiframe boundaries for the transmit side. See Figure 3-1 and the transmit
timing diagram (Figure 20-11).
In output mode, this pin is updated on the rising edge of TX CLOCK (an
internal signal) and can be programmed to output a frame or multiframe sync
pulse useful for aligning data. See Figure 3-1 and the transmit timing diagram
(Figure 20-11).
64KCC Mode: In input mode, this pin is sampled on the falling edge of TX
CLOCK (an internal signal) and will establish the boundary for the 8kHz
portion of the Composite Clock or the 400Hz boundary based on the setting of
IOCR1.3. See Figure 3-1 and the transmit timing diagram (Figure 20-11).
In output mode, this pin is updated on the rising edge of TX CLOCK (an
internal signal) and will indicate the 8kHz or 400Hz composite clock
alignment. See Figure 3-1 and the transmit timing diagram (Figure 20-11).
TCLKO O
Transmit Clock Output. In normal operation this output is the selected
transmit clock from the TX_PLL, TCLK pin or the recovered clock (RCLK).
When remote loopback is enabled this pin will output the recovered network
clock.
TPOSO O
Transmit Positive-Data Output. In T1 or E1 mode, updated on the rising
edge of TCLKO with the bipolar data out of the transmit-side formatter. Can
be programmed to source NRZ data via the output-data format (IOCR1.0)
control bit. In 64KCC or 6312kHz mode this pin will be low.
TNEGO O
Transmit Negative-Data Output. In T1 or E1 mode, updated on the rising
edge of TCLKO with the bipolar data out of the transmit-side formatter. In
64KCC or 6312kHz mode this pin will be low.
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4.3 Receive Side
NAME TYPE FUNCTION
RCLK O
Receive Clock. Recovered 1.544MHz (T1), 2.048MHz (E1), 6312 kHz
(G.703 Synchronization Interface), or 64 kHz (Composite Clock) clock.
RS_8K O
Receive Sync/8kHz Clock
T1/E1 Mode: An extracted pulse, one RCLK wide, is output at this pin that
identifies either frame (IOCR1.5 = 0) or multiframe (IOCR1.5 = 1)
boundaries. If set to output frame boundaries, then through IOCR1.6, RS_8K
can also be set to output double-wide pulses on signaling frames in T1 mode.
64KCC Mode: This pin will output the extracted 8 kHz portion of the
composite clock signal.
6312kHz Mode: This pin will be in a high-impedance state.
400HZ O
400Hz Clock Output
T1/E1 Mode: This pin will be in a high-impedance state.
64KCC Mode: This pin will output the 400Hz clock if enabled.
6312kHz Mode: This pin will be in a high-impedance state.
RSER O
Receive Serial Data
T1/E1 Mode: This is the received NRZ serial data updated on rising edges of
RCLK.
64KCC Mode: This pin will be in a high-impedance state.
6312kHz Mode: This pin will be in a high-impedance state.
RLOF_CCE O
Receive Loss Of Frame or Composite Clock Error. This output can be
configured to be a Loss Of Transmit Clock indicator via IOCR.4 when
operating in T1 or E1 mode.
T1/E1 Mode: Set when the receive synchronizer is searching for frame
alignment (RLOF mode), or set when the signal at the TCLK pin has not
transitioned for approximately 15 periods of the scaled MCLK (LOTC mode).
64KCC Mode: Active high when errors are detected in the 8kHz clock or
400Hz clock
6312kHz Mode: This pin will be in a high-impedance state.
RLOS O
Receive Loss Of Signal
T1 Mode: High when 192 consecutive zeros detected.
E1 Mode: High when 255 consecutive zeros detected.
64KCC Mode: High when consecutive zeros detected for 130µs typically.
6312kHz Mode: High when consecutive zeros detected for 65µs typically.
RAIS O
Receive Alarm Indication Signal
T1 Mode: Will toggle high when receive Blue Alarm is detected.
E1 Mode: Will toggle high when receive AIS is detected.
64KCC Mode: This pin will be in a high-impedance state.
6312kHz Mode: This pin will be in a high-impedance state.
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4.4 Controller Interface
NAME TYPE FUNCTION
INT/
JACKS0 I/O
Active-Low Interrupt/Jitter Attenuator Clock Select 0
INT
: Flags host controller during events, alarms, and conditions defined in
the status registers. Active-low open-drain output.
JACKS0: Hardware Mode: Jitter Attenuator Clock Select 0. Set this pin high
for T1 mode operation when either a 2.048MHz, 4.096MHz, 8.192MHz or
16.382MHz signal is applied at MCLK.
TMODE1 I
Transmit Mode Select 1. In Hardware Mode (BIS[1:0] = 11), this bit is used
to configure the transmit operating mode.
TMODE2 I
Transmit Mode Select 2. In Hardware Mode (BIS[1:0] = 11), this bit is used
to configure the transmit operating mode.
TSTRST I
Three-State Control and Device Reset. A dual-function pin. A zero-to-one
transition issues a hardware reset to the DS26502 register set. Configuration
register contents are set to the default state. Leaving TSTRST high three-
states all output and I/O pins (including the parallel control port). Set low for
normal operation. Useful for in-board level testing.
BIS[1:0] I
Bus Interface Mode Select 1, 0. These bits select the controller interface
mode of operation.
BIS[1:0] : 00 = Parallel Port Mode (Multiplexed)
01 = Parallel Port Mode (Nonmultiplexed)
10 = Serial Port Mode
11 = Hardware Mode
AD[7]/
RITD I/O
Data Bus D[7] or Address/Data Bus AD[7]/Receive Internal Termination
Disable
A[7]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data
bus D[7].
AD[7]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the
multiplexed address/data bus AD[7].
RITD: In Hardware Mode (BIS[1:0] = 11), internal receive termination is
disabled when RITD = 1.
AD[6]/
TITD I/O
Data Bus D[6] or Address/Data Bus AD[6]/Transmit Internal
Termination Disable
A[6]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data
bus D[6].
AD[6]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the
multiplexed address/data bus AD[6].
TITD: In Hardware Mode (BIS[1:0] = 11), internal transmit termination is
disabled when TITD = 1.
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NAME TYPE FUNCTION
AD[5]/
RMODE1 I/O
Data Bus D[5] or Address/Data Bus AD[5]/Receive Framing Mode Select
Bit 1
A[5]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as the
data bus D[5].
AD[5]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[5].
RMODE1: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive
side operating mode.
AD[4]/
RMODE0 I/O
Data Bus D[4] or Address/Data Bus AD[4]/Receive Framing Mode Select
Bit 0
A[4]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as the
data bus D[4].
AD[4]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[4].
RMODE0: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive
side operating mode.
AD[3]/TSM I/O
Data Bus D[3] or Address/Data Bus AD[3]/TS_8K_4 Mode Select
A[3]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as the
data bus D[3].
AD[3]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[3].
TSM: In Hardware Mode (BIS[1:0] = 11), this pin selects the function of
TS_8K_4. See the register descriptions for more detailed information.
AD[2]/RSM/
SCLK I/O
Data Bus D[2] or Address/Data Bus AD[2]/RS_8K Mode Select/
Serial Clock
A[2]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin as the data
bus D[2].
AD[2]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[2].
RSM: In Hardware Mode (BIS[1:0] = 11), this pin selects the function of
RS_8K. See the register descriptions for more detailed information.
SCLK: In Serial Port mode this is the serial clock input.
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NAME TYPE FUNCTION
AD[1]/
RMODE3/
MOSI
I/O
Data Bus D[1] or Address/Data Bus AD[1]/Receive Mode Select 3/Master
Out-Slave In
A[1]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as the
data bus D[1].
AD[1]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[1].
RMODE3: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive
side operating mode.
MOSI: Serial data input called Master Out-Slave In for clarity of data transfer
direction.
AD[0]/
TCSS0/
MISO
I/O
Data Bus D[0] or Address/Data Bus AD[0]/Transmit Clock Source
Select 0/Master In-Slave Out
A[0]: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as the
data bus D[0].
AD[0]: In multiplexed bus operation (BIS[1:0] = 00), this pin serves as the
multiplexed address/data bus AD[0].
TCSS0: Transmit Clock Source Select 0.
MISO: In serial bus mode (BIS[1:0] = 10), this pin serves as the serial data
output Master In-Slave Out.
TCSS1 I Transmit Clock Source Select. Transmit Clock Source Select 1
A6/MPS0 I
Address Bus Bit A[6]/MCLK Prescale Select
A6: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[6].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
MPS0: In Hardware Mode (BIS[1:0] = 11), MCLK prescale select is used to
set the prescale value for the PLL.
A5/CPOL/
TMODE0
I
Address Bus Bit A[5]/Serial Port Clock Polarity Select/Transmit Mode
Select 0
A5: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[5].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
CPOL: In Serial Port Mode (BIS[1:0] = 10), this pin selects the serial port
clock polarity. Please see the functional timing diagrams for the Serial Port
Interface for more information.
TMODE0: In Hardware Mode (BIS[1:0] = 11), this pin is used to configure
the transmit operating mode.
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NAME TYPE FUNCTION
A4/CPHA/
L2 I
Address Bus Bit A[4]/Serial Port Clock Phase Select/Line Build-Out
Select 2
A4: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[4].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
CPHA: In Serial Port Mode (BIS[1:0] = 10), this pin selects the serial port
clock phase. See the functional timing diagrams for the Serial Port Interface
for more information.
L2: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A3/L1 I
Address Bus Bit A[3]/Line Build-Out Select 1
A3: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[3].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
L1: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A2/L0 I
Address Bus Bit A[2]/Line Build-Out Select 0
A2: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[2].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
L0: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out
value.
A1/TAIS
I
Address Bus Bit A[1]/Transmit AIS
A1: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[1].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
TAIS: When set to a 0 and in T1/E1 operating modes, the tran smitter will
transmit an AIS pattern. Set to a 1 for normal operation. This pin is ignored in
all other operating modes.
A0/E1TS I
Address Bus Bit A[0]/E1 Termination Select
A0: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[0].
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and
should be tied low.
E1TS: In Hardware Mode (BIS[1:0] = 11), selects the E1 internal termination
value (0 = 75Ω, 1 = 120Ω).
BTS/HBE I
Bus Type Select/Transmit and Receive B8ZS/HDB3 Enable
BTS: Strap high to select Motorola bus timing; strap low to select Intel bus
timing. This pin controls the function of the RD (DS), ALE (AS), and WR
(R/W) pins. If BTS = 1, then these pins assume the function listed in
parentheses ().
HBE: In Hardware Mode (BIS[1:0] = 11), this pin enables transmit and
receive B8ZS/HDB3 when in T1/E1 operating modes.
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NAME TYPE FUNCTION
RD(DS)/
RMODE2 I
Read Input-Data Strobe/Receive Mode Select Bit 2
RD
(
DS
): These pins are active-low signals. DS is active high when BIS[1:0]
= 01. See the bus timing diagrams.
RMODE2: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive
side operating mode.
CS/RLB I
Chip Select/Remote Loopback Enable
CS
: This active-low signal must be low to read or write to the device. This
signal is used for both the parallel port and the serial port modes.
RLB: In Hardware Mode (BIS[1:0] = 11), when high, remote loopback is
enabled. This function is only valid when the transmit side and receive side
are in the same operating mode.
ALE (AS)/
A7/MPS1 I
Address Latch Enable (Address Strobe)/Address Bus Bit 7/MCLK
Prescale Select 1
ALE (AS): In multiplexed bus operation (BIS[1:0] = 00), it serves to
demultiplex the bus on a positive-going edge.
A7: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[7].
MPS1: In Hardware Mode (BIS[1:0] = 11), MCLK prescale select, used to set
the prescale value for the PLL.
WR (R/W)/
TMODE3 I
Write Input (Read/Write)/Transmit Mode Select 3
WR
: In Processor Mode, this pin is the active-low write signal.
TMODE3: In Hardware Mode, this pin selects the transmit-side operating
mode.
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4.5 JTAG
NAME TYPE FUNCTION
JTCLK I
JTAG Clock. This clock input is typically a low frequency (less than 10MHz)
50% duty cycle clock signal.
JTMS I
JTAG Mode Select (with Pullup). This input signal is used to control the
JTAG controller state machine and is sampled on the rising edge of JTCLK.
JTDI I
JTAG Data Input (with Pullup). This input signal is used to input data into
the register that is enabled by the JTAG controller state machine and is sampled
on the rising edge of JTCLK.
JTDO O
JTAG Data Output. This output signal is the output of an internal scan shift
register enabled by the JTAG controller state machine and is updated on the
falling edge of JTCLK. The pin is in the high-impedance mode when a register
is not selected or when the JTRST signal is high. The pin goes into and exits the
high impedance mode after the falling edge of JTCLK
JTRST I
JTAG Reset (Active Low). This input forces the JTAG controller logic into
the reset state and forces the JTDO pin into high impedance when low. This pin
should be low while power is applied and set high after the power is stable.
The pin can be driven high or low for normal operation, but must be high for
JTAG operation.
4.6 Line Interface
NAME TYPE FUNCTION
MCLK I
Master Clock Input. A (50ppm) clock source. This clock is used internally for
both clock/data recovery and for the jitter attenuator for both T1 and E1 modes.
The clock rate can be 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz. When
using the DS26502 in T1-only operation, a 1.544MHz (50ppm) clock source
can be used.
RTIP I
Receive Tip. Analog input for clock recovery circuitry. This pin connects via a
1:1 transformer to the network. See the Line Interface Unit section for details.
RRING I
Receive Ring. Analog input for clock recovery circuitry. This pin connects via
a 1:1 transformer to the network. See the Line Interface Unit section for details.
TTIP O
Transmit Tip. Analog line-driver output. This pin connects via a 1:2 step-up
transformer to the network. See the Line Interface Unit section for details.
TRING O
Transmit Ring. Analog line-driver output. This pin connects via a 1:2 step-up
transformer to the network. See the Line Interface Unit section for details.
THZE I
Transmit High-Impedance Enable. When high, TTIP and TRING will be
placed into a high-impedance state.
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4.7 Power
NAME TYPE FUNCTION
DVDD —
Digital Positive Supply. 3.3V ±5%. Should be tied to the RVDD and TVDD
pins.
RVDD —
Receive Analog Positive Supply. 3.3V ±5%. Should be tied to the DVDD and
TVDD pins.
TVDD —
Transmit Analog Positive Supply. 3.3V ±5%. Should be tied to the DVDD
and RVDD pins.
DVSS — Digital Signal Ground. 0.0V. Should be tied to the RVSS and TVSS pins.
RVSS —
Receive Analog Signal Ground. 0.0V. Should be tied to the DVSS and TVSS
pins.
TVSS —
Transmit Analog Signal Ground. 0.0V. Should be tied to the DVSS and
RVSS pins.
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5. PINOUT
Table 5-1. LQFP Pinout
MODE
PIN TYPE PARALLEL
PORT
SERIAL
PORT HARDWARE FUNCTION
1 I/O AD2 SCLK RSM
Parallel Port Mode: Address/Data Bus Bit 2
Serial Port Mode: Serial Clock
Hardware Mode: RS_8K Mode Select
2 I/O AD3 — TSM
Parallel Port Mode: Address/Data Bus Bit 3
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: TS_8K_4 Mode Select
3 I/O AD4 — RMODE0
Parallel Port Mode: Address/Data Bus Bit 4
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Receive Mode Select 0
4 I/O AD5 — RMODE1
Parallel Port Mode: Address/Data Bus Bit 5
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Receive Mode Select 1
5 I/O AD6 — TITD
Parallel Port Mode: Address/Data Bus Bit 6
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit Internal Termination Disable
6 I/O AD7 — RITD
Parallel Port Mode: Address/Data Bus Bit 7
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Receive Internal Termination Disable
7, 24,
58 I DVDD DVDD DVDD Digital Positive Supply
8, 22,
56 I DVSS DVSS DVSS Digital Signal Ground
9 I A0 — E1TS
Parallel Port Mode: Address Bus Bit 0
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: E1 Internal Termination Select
10 I A1 — TAIS
Parallel Port Mode: Address Bus Bit 1
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit AIS
11 I A2 — L0
Parallel Port Mode: Address Bus Bit 2
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Line Build-Out Select 0
12 I A3 — L1
Parallel Port Mode: Address Bus Bit 3
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Line Build-Out Select 1
13 I A4 CPHA L2
Parallel Port Mode: Address Bus Bit 4
Serial Port Mode: Serial Port Clock Phase Select
Hardware Mode: Line Build-Out Select 2
14 I A5 CPOL TMODE0
Parallel Port Mode: Address Bus Bit 5
Serial Port Mode: Serial Port Clock Polarity Select
Hardware Mode: Transmit Mode Select 0
15 I A6 — MPS0
Parallel Port Mode: Address Bus Bit 6
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: MCLK Pre-Scaler Select 0
16 I ALE (AS)/A7 — MPS1
Parallel Port Mode: Address Latch Enable/Address Bus
Bit 7
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: MCLK Pre-Scaler Select 1
17 I TCLK TCLK TCLK Transmit Clock Input
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MODE
PIN TYPE PARALLEL
PORT
SERIAL
PORT HARDWARE FUNCTION
18 O TCLKO TCLKO TCLKO Transmit Clock Output
19 O TNEGO TNEGO TNEGO Transmit Negative-Data Output
20 O TPOSO TPOSO TPOSO Transmit Positive-Data Output
21 I TSER TSER TSER Transmit Serial Data
23 I/O TS_8K_4 TS_8K_4 TS_8K_4
T1/E1 Mode: Transmit Frame/Multiframe Sync
64KCC Mode: Transmit 8kHz or 400Hz Sync
25 O RCLK RCLK RCLK Receive Clock
26 O RS_8K RS_8K RS_8K
T1/E1 Mode: Receive Frame/Multiframe Boundary
64KCC Mode: Receive 8kHz Output
27 O 400HZ 400HZ 400HZ 400Hz Output in Composite Clock Mode
28 O RSER RSER RSER Receive Serial Data
29 O RAIS RAIS RAIS Receive Alarm Indication Signal
30 O RLOF_CCE RLOF_CCE RLOF_CCE Receive Loss of Frame_Composite Clock Error
31 I — — TCSS1
Parallel Port Mode: Unused, should be connected to
VSS.
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit Clock Source Select 1
32 O RLOS RLOS RLOS Receive Loss Of Signal
33 I JTMS JTMS JTMS IEEE 1149.1 Test Mode Select
34 I JTCLK JTCLK JTCLK IEEE 1149.1 Test Clock Signal
35 I JTRST JTRST JTRST
IEEE 1149.1 Test Reset
36 I JTDI JTDI JTDI IEEE 1149.1 Test Data Input
37 O JTDO JTDO JTDO IEEE 1149.1 Test Data Output
38 I RVDD RVDD RVDD Receive Analog Positive Supply
39 I TSTRST TSTRST TSTRST Test/Reset
40,
43, 45 I RVSS RVSS RVSS Receive Analog Signal Ground
41 I RTIP RTIP RTIP Receive Analog Tip Input
42 I RRING RRING RRING Receive Analog Ring Input
44 I MCLK MCLK MCLK Master Clock Input
46 I/O INT INT
JACKS0
Parallel Port Mode: Active-Low Interrupt
Serial Port Mode: Active-Low Interrupt
Hardware Mode: Jitter Attenuator Clock Select 0
47 O PLL_OUT PLL_OUT PLL_OUT Transmit PLL (TX PLL) Clock Output
48 I — — TMODE2
Parallel Port Mode: Unused, should be connected to
VSS.
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit Mode Select 2
49 I — — TMODE1
Parallel Port Mode: Unused, should be connected to
VSS.
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit Mode Select 1
50 I THZE THZE THZE Transmit High-Impedance Enable
51 O TTIP TTIP TTIP Transmit Analog Tip Output
52 I TVSS TVSS TVSS Transmit Analog Signal Ground
53 I TVDD TVDD TVDD Transmit Analog Positive Supply
54 O TRING TRING TRING Transmit Analog Ring Output
55 I BTS — HBE
Parallel Port Mode: Bus Type Select (Motorola/Intel)
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Receive and Transmit DB3/B8ZS
Enable
57 I BIS0 BIS0 BIS0 Bus Interface Select Mode 0
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MODE
PIN TYPE PARALLEL
PORT
SERIAL
PORT HARDWARE FUNCTION
59 I BIS1 BIS1 BIS1 Bus Interface Select Mode 1
60 I CS CS
RLB
Parallel Port Mode: Active-Low Chip Select
Serial Port Mode: Active-Low Chip Select
Hardware Mode: Remote Loopback Enable
61 I RD (DS) — RMODE2
Parallel Port Mode: Active-Low Read Input (Data
Strobe)
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Receive Mode Select 2
62 I WR (R/W) — TMODE3
Parallel Port Mode: Active-Low Write Input
(Read/Write)
Serial Port Mode: Unused, should be connected to VSS.
Hardware Mode: Transmit Mode Select 3
63 I/O AD0 MIS0 TCSS0
Parallel Port Mode: Address/Data Bus Bit 0
Serial Port Mode: Serial Data Out (Master In-Slave
Out)
Hardware Mode: Transmit Clock Source Select 0
64 I/O AD1 MOSI RMODE3
Parallel Port Mode: Address/Data Bus Bit 1
Serial Port Mode: Serial Data In (Master Out-Slave In)
Hardware Mode: Receive Mode Select 3
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6. HARDWARE CONTROLLER INTERFACE
In Hardware Controller mode, the parallel and serial port pins are reconfigured to provide direct access to
certain functions in the port. Only a subset of the device’s functionality is available in hardware mode.
Each register description throughout the data sheet indicates the functions that may be controlled in
hardware mode and several alarm indicators that are available in both hardware and processor mode.
Also indicated are the fixed states of the functions not controllable in hardware mode.
6.1 Transmit Clock Source
Refer to Figure 3-3. In Hardware Controller mode, the input to the TX PLL is always TCLK PIN. TX
CLOCK is selected by the TCSS0 and TCSS1 pins, as shown in Table 6-1. The PLL_OUT pin is always
the same signal as select for TX CLOCK. If the user wants to slave the transmitter to the recovered
clock, then the RCLK pin must be tied to the TCLK pin externally.
Table 6-1. Transmit Clock Source
TCSS1
PIN 31
TCSS0
PIN 63 TRANSMIT CLOCK SOURCE
0 0 The TCLK pin is the source of transmit clock.
0 1 The PLL_CLK is the source of transmit clock.
1 0
The scaled signal present at MCLK as the transmit
clock.
1 1 The signal present at RCLK is the transmit clock.
6.2 Internal Termination
In Hardware Controller mode, the internal termination is automatically set according to the receive or
transmit mode selected. It can be disabled via the TITD and RITD pins. If internal termination is enabled
in E1 mode, the E1TS pin is use to select 75Ω or 120Ω termination. The E1TS pin applies to both
transmit and receive.
Table 6-2. Internal Termination
PIN NAME FUNCTION
TITD
PIN 5
Transmit Internal Termination Disable. Disables the internal transmit
termination. The internal transmit termination value is dependent on the state of
the TMODEx pins.
RITD
PIN 6
Receive Internal Termination Disable. Disables the internal receive
termination. The internal receive termination value is dependent on the state of
the RMODEx pins.
E1TS
PIN 9
E1 Termination Select. Selects 120Ω or 75Ω internal termination when one of
the E1 modes is selected and internal termination is enabled. IF E1 is selected for
both transmit and receive, then both terminations will be the same.
0 = 75Ω
1 = 120Ω
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6.3 Line Build-Out
Table 6-3. E1 Line Build-Out
L2
PIN 13
L1
PIN 12
L0
PIN 11 APPLICATION N
(NOTE 1)
RETURN
LOSS
Rt
(NOTE 1)
0 0 0 75Ω normal 1:2 N.M. 0
0 0 1 120Ω normal 1:2 N.M. 0
1 0 0 75Ω with high return loss (Note 2) 1:2 21dB 6.2Ω
1 0 1 120Ω with high return loss (Note 2) 1:2 21dB 11.6Ω
1 1 0 Reserved — — —
1 1 1 Reserved — — —
Table 6-4. T1 Line Build-Out
L2
PIN 13
L1
PIN 12
L0
PIN 11 APPLICATION N
(NOTE 1)
RETURN
LOSS
Rt
(NOTE 1)
0 0 0 DSX-1 (0 to 133 feet)/0dB CSU 1:2 N.M. 0
0 0 1 DSX-1 (133 to 266 feet) 1:2 N.M. 0
0 1 0 DSX-1 (266 to 399 feet) 1:2 N.M. 0
0 1 1 DSX-1 (399 to 533 feet) 1:2 N.M. 0
1 0 0 DSX-1 (533 to 655 feet) 1:2 N.M. 0
1 0 1 Reserved — — —
1 1 0 Reserved — — —
1 1 1 Reserved — — —
Note 1: Transformer turns ratio.
Note 2: TTD pin must be connected high in this mode.
N.M. = not meaningful
6.4 Receiver Operating Modes
Table 6-5. Receive Path Operating Mode
RMODE3
PIN 64
RMODE2
PIN 61
RMODE1
PIN 4
RMODE0
PIN 3 RECEIVE PATH OPERATING MODE
0 0 0 0 T1 D4
0 0 0 1 T1 ESF
0 0 1 0 J1 D4
0 0 1 1 J1 ESF
0 1 0 0 E1 FAS
0 1 0 1 E1 CAS
0 1 1 0 E1 CRC4
0 1 1 1 E1 CAS and CRC4
1 0 0 0 E1 G.703 2048kHz Synchronization Interface
1 0 0 1 64kHz + 8kHz Synchronization Interface
1 0 1 0 64kHz + 8kHz + 400Hz Synchronization Interface
1 0 1 1 6312kHz Synchronization Interface
1 1 0 0 Reserved
1 1 0 1 Reserved
1 1 1 0 Reserved
1 1 1 1 Reserved
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6.5 Transmitter Operating Modes
Table 6-6.Transmit Path Operating Mode
TMODE3
PIN 62
TMODE2
PIN 48
TMODE1
PIN 49
TMODE0
PIN 14 TRANSMIT PATH OPERATING MODE
0 0 0 0 T1 D4
0 0 0 1 T1 ESF
0 0 1 0 J1 D4
0 0 1 1 J1 ESF
0 1 0 0 E1 FAS
0 1 0 0 E1 FAS + CAS (Note 1)
0 1 0 1 Reserved
0 1 1 0 E1 CRC4
0 1 1 0 E1 CRC4 + CAS (Note 1)
0 1 1 1 Reserved
1 0 0 0 E1 G.703 2048kHz Synchronization Interface
1 0 0 1 64kHz + 8kHz Synchronization Interface
1 0 1 0 64kHz + 8kHz + 400Hz Synchronization Interface
1 0 1 1 6312kHz Synchronization Interface (Note 2)
1 1 0 0 Reserved
1 1 0 1 Reserved
1 1 1 0 Reserved
1 1 1 1 Reserved
Note 1: The DS26502 does not have an internal source for CAS signaling and multiframe alignment generation. CAS
signaling, and the multiframe alignment word, must be embedded in the transmit data (in the TS16 position) present
on the TSER pin and frame aligned to sync signal on the TS_8K_4 pin.
Note 2: In addition to setting the TMODE bits to 6312kHz Synchronization Interface mode, the Transmit PLL must also be
configured to transmit a 6312kHz signal through the Transmit PLL Control Register (TPCR.6 and TPCR.7).
6.6 MCLK Pre-Scaler
Table 6-7. MCLK Pre-Scaler for T1 Mode
MPS1
PIN 16
MPS0
PIN 15
JACKS0
PIN 46
MCLK
(MHz)
0 0 0 1.544
0 1 0 3.088
1 0 0 6.176
1 1 0 12.352
0 0 1 2.048
0 1 1 4.096
1 0 1 8.192
1 1 1 16.384
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Table 6-8. MCLK Pre-Scaler for E1 Mode
MPS1
PIN 16
MPS0
PIN 15
JACKS0
PIN 46
MCLK
(MHz)
0 0 0 2.048
0 0 1 Reserved
0 1 0 4.096
0 1 1 Reserved
1 0 0 8.192
1 0 1 Reserved
1 1 0 16.384
1 1 1 Reserved
6.7 Other Hardware Controller Mode Features
Table 6-9. Other Operational Modes
PIN
NAME DESCRIPTION
RSM
PIN 1
RS_8K Mode Select: Selects frame or multiframe pulse at RS_8K pin.
0 = frame mode
1 = multiframe mode
TSM
PIN2
TS_8K_4 Mode Select: In T1 or E1 operation, selects frame or multiframe mode for the
TS_8K_4 pin.
0 = frame mode
1 = multiframe mode
RLB
PIN 60
Remote Loopback Enable: In this loopback, data input to the framer portion of the
DS26502 will be transmitted back to the transmit portion of the LIU. Data will continue
to pass through the receive side framer of the DS26502 as it would normally and the data
from the transmit side formatter will be ignored.
0 = loopback disabled
1 = loopback enabled
TAIS
PIN 10
Transmit AIS
0 = transmit AIS alarm
1 = normal transmission
HBE
PIN 55
Receive and Transmit HDB3/B8ZS Enable
0 = HDB3/B8ZS disabled
1 = HDB3/B8ZS enabled
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7. PROCESSOR INTERFACE
The DS26502 is controlled via a nonmultiplexed (BIS[1:0] = 01) or a multiplexed (BIS[1:0] = 00)
parallel bus. There is also a serial bus mode option, as well as a hardware mode of operation. The bus
interface type is selected by BIS1 and BIS0 as shown in Table 7-1.
Table 7-1. Port Mode Select
BIS1 BIS0 PORT MODE
0 0 Parallel Port Mode (Multiplexed)
0 1 Parallel Port Mode (Nonmultiplexed)
1 0 Serial Port Mode (SPI)
1 1 Hardware Mode
7.1 Parallel Port Functional Description
In parallel mode, the DS26502 can operate with either Intel or Motorola bus timing configurations. If the
BTS pin is tied low, Intel timing will be selected; if tied high, Motorola timing will be selected. All
Motorola bus signals are listed in parentheses (). See the timing diagrams in the AC Electrical
Characteristics section for more details.
7.2 SPI Serial Port Interface Functional Description
A serial SPI bus interface is selected when bus select is 10 (BIS[1:0] = 10). In this mode, a master/slave
relationship is enabled on the serial port with three signal lines (SCK, MOSI and MISO) and a chip select
(CS), with the DS26502 acting as the slave. Port read/write timing is not related to the system read/write
timing, thus allowing asynchronous, half-duplex operation. See the AC Electrical Characteristics section
for the AC timing characteristics of the serial port.
7.2.1 Clock Phase and Polarity
Clock Phase and Polarity are selected by the CPHA and CPOL pins. The slave device should always be
configured to match the bus master. See the SPI Serial Port Mode section for detailed functional timing
diagrams.
7.2.2 Bit Order
The most significant bit (MSB) of each byte is transmitted first.
7.2.3 Control Byte
The bus master will transmit two control bytes following a chip select to a slave device. The MSB will be
a R/W bit (1=read, 0=write). The next 6 bits will be padded with 0s. The LSB of the first byte will be
A[7]. The second control byte will be the address bits (A[6:0]) of the target register, followed by a Burst
bit in the LSB position (1=Burst, 0=Non-burst).
7.2.4 Burst Mode
The last bit of the second control byte (LSB) is the Burst mode bit. When the Burst bit is enabled (set to
1) and a read operation is performed, the register address is automatically incremented after the LSB of
the previous byte read to the next register address. Data will be available on the next clock edge following
the LSB of the previous byte read. When the Burst bit is enabled (set to 1) and a write operation is
performed, the register address will be automatically incremented to the next byte boundary following the
LSB of the previous register write, and 8 more data bits will be expected on the serial bus. Burst accesses
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are terminated when CS is removed. If CS is removed before all 8 bits of the data are read, the remaining
data will be lost. If CS is removed before all 8 bits of data are written to the part, no write access will
occur and the target register will not be updated.
Note: During a Burst read access, data must be fetched internally to the part as the LSB of the previous
byte is transmitted out. If this pre-fetch read access occurs to a Clear-On-Read register or a FIFO register
address, and the Burst access is terminated without reading this byte out of the port, the data will be lost
and/or the register cleared. Users should not terminate their Burst Read accesses at the address byte
proceeding a Clear-On-Read register or a FIFO register. Data loss could occur due to the internal pre-
fetch operation performed by the interface.
7.2.5 Register Writes
The register write sequence is shown in the functional timing diagrams in Section 18. After a CS, the bus
master transmits a write control byte containing the R/W bit, the target register address, and the Burst bit.
These two control bytes will be followed by the data byte to be written. After the first data byte, if the
Burst bit is set, the DS26502 auto-increments its address counter and writes each byte received to the next
higher address location. After writing address FFh, the address counter rolls over to 00h and continues to
auto-increment.
7.2.6 Register Reads
The register read sequence is shown in Section 18. After a CS, the bus master transmits a read control
byte containing the R/W bit, the target register address, and the Burst bit. After these two control bytes,
the DS26502 responds with the requested data byte. After the first data byte, if the Burst bit is set, the
DS26502 auto-increments its address counter and transmits the byte stored in the next higher address
location. Note the warning mentioned above as data loss could potentially occur due to the data pre-fetch
that is required to support this mode. After reading address FFh, the address counter rolls over to 00h and
continues to auto-increment.
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7.3 Register Map
Table 7-2. Register Map Sorted By Address
ADDRESS TYPE REGISTER NAME REGISTER
ABBREVIATION
00 R/W Test Reset Register TSTRREG
01 R/W I/O Configuration Register 1 IOCR1
02 R/W I/O Configuration Register 2 IOCR2
03 R/W T1 Receive Control Register 1 T1RCR1
04 R/W T1 Receive Control Register 2 T1RCR2
05 R/W T1 Transmit Control Register 1 T1TCR1
06 R/W T1 Transmit Control Register 2 T1TCR2
07 R/W T1 Common Control Register T1CCR
08 R/W Mode Configuration Register MCREG
09 R/W Transmit PLL Control Register TPCR
0A — Reserved —
0B — Reserved —
0C — Reserved —
0D — Reserved —
0E — Reserved —
0F — Reserved —
10 R Device Identification Register IDR
11 R Information Register 1 INFO1
12 R Information Register 2 INFO2
13 R Interrupt Information Register IIR
14 R Status Register 1 SR1
15 R/W Interrupt Mask Register 1 IMR1
16 R Status Register 2 SR2
17 R/W Interrupt Mask Register 2 IMR2
18 R Status Register 3 SR3
19 R/W Interrupt Mask Register 3 IMR3
1A R Status Register 4 SR4
1B R/W Interrupt Mask Register 4 IMR4
1C R Information Register 3 INFO3
1D R/W E1 Receive Control Register E1RCR
1E R/W E1 Transmit Control Register E1TCR
1F R/W BOC Control Register BOCC
20 R/W Loopback Control Register LBCR
21-2F — Reserved —
30 R/W Line Interface Control 1 LIC1
31 R/W Line Interface Control 2 LIC2
32 R/W Line Interface Control 3 LIC3
33 R/W Line Interface Control 4 LIC4
34 R/W Transmit Line Build-Out Control TLBC
35-3F — Reserved —
40 R/W Transmit Align Frame Register TAF
41 R/W Transmit Non-Align Frame Register TNAF
42 R/W Transmit Si Align Frame TSiAF
43 R/W Transmit Si Non-Align Frame TSiNAF
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ADDRESS TYPE REGISTER NAME REGISTER
ABBREVIATION
44 R/W Transmit Remote Alarm Bits TRA
45 R/W Transmit Sa4 Bits TSa4
46 R/W Transmit Sa5 Bits TSa5
47 R/W Transmit Sa6 Bits TSa6
48 R/W Transmit Sa7 Bits TSa7
49 R/W Transmit Sa8 Bits TSa8
4A R/W Transmit Sa Bit Control Register TSACR
4B-4F — Reserved —
50 R Receive FDL Register RFDL
51 R/W Transmit FDL Register TFDL
52 R/W Receive Facility Data Link Match Register 1 RFDLM1
53 R/W Receive Facility Data Link Match Register 2 RFDLM2
54-55 — Reserved —
56 R Receive Align Frame Register RAF
57 R Receive Non-Align Frame Register RNAF
58 R Receive Si Align Frame RSiAF
59 R Receive Si Non-Align Frame RSiNAF
5A R Receive Remote Alarm Bits RRA
5B R Receive Sa4 Bits RSa4
5C R Receive Sa5 Bits RSa5
5D R Receive Sa6 Bits RSa6
5E R Receive Sa7 Bits RSa7
5F R Receive Sa8 Bits RSa8
60-EF — Reserved —
F0 R/W Test Register 1 TEST1*
F1 R/W Test Register 2 TEST2*
F2 R/W Test Register 3 TEST3*
F3 R/W Test Register 4 TEST4*
F4 R/W Test Register 5 TEST5*
F5 R/W Test Register 6 TEST6*
F6 R/W Test Register 7 TEST7*
F7 R/W Test Register 8 TEST8*
F8 R/W Test Register 9 TEST9*
F9 R/W Test Register 10 TEST10*
FA R/W Test Register 11 TEST11*
FB R/W Test Register 12 TEST12*
FC R/W Test Register 13 TEST13*
FD R/W Test Register 14 TEST14*
FE R/W Test Register 15 TEST15*
FF R/W Test Register 16 TEST16*
*TEST1 to TEST16 registers are used only by the factory.
DS26502
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7.3.1 Power-Up Sequence
The DS26502 contains an on-chip power-up reset function, which automatically clears the writeable
register space immediately after power is supplied to the device. The user can issue a chip reset at any
time. Issuing a reset will disrupt signals flowing through the DS26502 until the device is reprogrammed.
The reset can be issued through hardware using the TSTRST pin or through software using the SFTRST
function in the master mode register. The LIRST (LIC2.6) should be toggled from zero to one to reset the
line interface circuitry. (It will take the DS26502 about 40ms to recover from the LIRST bit being
toggled.)
7.3.2 Test Reset Register
Register Name: TSTRREG
Register Descript i on: Test Reset Register
Register Address: 00h
Bit # 7 6 5 4 3 2 1 0
Name — — TEST1 TEST0 — — — SFTRST
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Software Issued Reset (SFTRST). A zero-to-one transition causes the register space in the DS26502 to be cleared. A
reset clears all configuration and status registers. The bit automatically clears itself when the reset has completed.
Bits 1 to 3: Unused, must be set = 0 for proper operation.
Bits 4 and 5: Test Mode Bits (TEST0, TEST1). Test modes are used to force the output pins of the DS26502 into known
states. This can facilitate the checkout of assemblies during the manufacturing process and also be used to isolate devices from
shared buses.
TEST1 TEST0 Effect On Output Pins
0 0 Operate normally
0 1 Force all output pins into three-state (including all I/O pins and parallel port pins)
1 0 Force all output pins low (including all I/O pins except parallel port pins)
1 1 Force all output pins high (including all I/O pins except parallel port pins)
Bits 6 and 7: Unused, must be set = 0 for proper operation.
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7.3.3 Mode Configuration Register
Register Name: MCREG
Register Description: Mode Configuration Register
Register Address: 08h
Bit # 7 6 5 4 3 2 1 0
Name TMODE3 TMODE2 TMODE1 TMODE0 RMODE3 RMODE2 RMODE1 RMODE0
Default 0 0 0 0 0 0 0 0
HW
Mode
TMODE3
PIN 62
TMODE2
PIN 48
TMODE1
PIN 49
TMODE0
PIN 14
RMODE3
PIN 64
RMODE2
PIN 61
RMODE1
PIN 4
RMODE0
PIN 3
Bit 0 to 3: Receive Mode Configuration (RMODE[3:0]). Used to select the operating mode of the receive path for the
DS26502.
RMODE3 RMODE2 RMODE1 RMODE0 Receive Path Operating Mode
0 0 0 0 T1 D4
0 0 0 1 T1 ESF
0 0 1 0 J1 D4
0 0 1 1 J1 ESF
0 1 0 0 E1 FAS
0 1 0 1 E1 CAS
0 1 1 0 E1 CRC4
0 1 1 1 E1 CAS and CRC4
1 0 0 0 E1 G.703 2048kHz Synchronization Interface
1 0 0 1 64kHz + 8 kHz Synchronization Interface
1 0 1 0 64kHz + 8kHz + 400Hz Synchronization Interface
1 0 1 1 6312kHz Synchronization Interface
1 1 0 0 Reserved
1 1 0 1 Reserved
1 1 1 0 Reserved
1 1 1 1 Reserved
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Bits 4 to 7: Transmit Mode Configuration (TMODE[3:0]). Used to select the operating mode of the transmit path for the
DS26502.
TMODE3 TMODE2 TMODE1 TMODE0 Transmit Path Operating Mode
0 0 0 0 T1 D4
0 0 0 1 T1 ESF (Note: In this mode the TFSE (T1TCR2.6) bit should be
set = 0.)
0 0 1 0 J1 D4
0 0 1 1 J1 ESF
0 1 0 0 E1 FAS
0 1 0 0 E1 FAS + CAS (Note 1)
0 1 0 1 Reserved
0 1 1 0 E1 CRC4
0 1 1 0 E1 CRC4 + CAS (Note 1)
0 1 1 1 Reserved
1 0 0 0 E1 G.703 2048 kHz Synchronization Interface
1 0 0 1 64kHz + 8kHz Synchronization Interface
1 0 1 0 64kHz + 8kHz + 400Hz Synchronization Interface
1 0 1 1 6312kHz Synchronization Interface (Note 2)
1 1 0 0 Reserved
1 1 0 1 Reserved
Note 1: The DS26502 does not have an internal source for CAS signaling and multiframe alignment generation. CAS signaling, and the
multiframe alignment word, must be embedded in the transmit data (in the TS16 position) present on the TSER pin and frame
aligned to sync signal on the TS_8K_4 pin.
Note 2: In addition to setting the TMODE bits to 6312kHz Synchronization Interface mode, the Transmit PLL must also be configured to
transmit a 6312kHz signal through the Transmit PLL Control Register (TPCR.6 and TPCR.7)
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Register Name: TPCR
Register Description: Transmit PLL Control Register
Register Address: 09h
Bit # 7 6 5 4 3 2 1 0
Name TPLLOFS1 TPLLOFS0 PLLOS TPLLIFS1 TPLLIFS0 TPLLSS TCSS1 TCSS0
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0
TCSS1
PIN 31
TCSS0
PIN 63
For more information on all the bits in the Transmit PLL control register, refer to Figure 3-3.
Bits 0 and 1: Transmit Clock (TX CLOCK) Source Select (TCSS[1:0]). These bits control the output of the TX PLL
Clock Mux function. See Figure 3-3.
TCSS1 TCSS0 Transmit Clock (TX CLOCK) Source
(See Figure 3-3)
0 0 The TCLK pin is the source of transmit clock.
0 1 The PLL_CLK is the source of transmit clock.
1 0 The scaled signal present at MCLK as the transmit clock.
1 1 The signal present at RCLK is the transmit clock.
Bit 2: Transmit PLL_CLK Source Select (TPLLSS). Selects the reference signal for the TX PLL.
0 = Use the recovered network clock. This is the same clock available at the RCLK pin (output).
1 = Use the externally provided clock present at the TCLK pin.
Bit 3 and 4: Transmit PLL Input Frequency Select (TPLLIFS[0:1]). These bits are used to indicate the reference
frequency being input to the TX PLL.
TPLLIFS1 TPLLIFS0 Input Frequency
0 0 1.544MHz
0 1 2.048MHz
1 0 64kHz
1 1 6312kHz
Bit 5: PLL_OUT Select (PLLOS). This bit selects the source for the PLL_OUT pin. See Figure 3-3.
0 = PLL_OUT is sourced directly from the TX PLL.
1 = PLL_OUT is the output of the TX PLL mux.
Bits 6 and 7: Transmit PLL Output Frequency Select (TPLLOFS[1:0]). These bits are used to select the TX PLL output
frequency.
TPLLOFS1 TPLLOFS0 Output Frequency
0 0 1.544MHz
0 1 2.048MHz
1 0 64kHz
1 1 6312kHz
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7.4 Interrupt Handling
Various alarms, conditions, and events in the DS26502 can cause interrupts. For simplicity, these are all
referred to as events in this explanation. All STATUS registers can be programmed to produce interrupts.
Each status register has an associated interrupt mask register. For example, SR1 (Status Register 1) has an
interrupt control register called IMR1 (Interrupt Mask Register 1). Status registers are the only sources of
interrupts in the DS26502. On power-up, all writeable registers are automatically cleared. Since bits in
the IMRx registers have to be set = 1 to allow a particular event to cause an interrupt, no interrupts can
occur until the host selects which events are to product interrupts. Since there are potentially many
sources of interrupts on the DS26502, several features are available to help sort out and identify which
event is causing an interrupt. When an interrupt occurs, the host should first read the IIR register
(interrupt information register) to identify which status register(s) is producing the interrupt. Once that is
determined, the individual status register or registers can be examined to determine the exact source.
Once an interrupt has occurred, the interrupt handler routine should clear the IMRx registers to stop
further activity on the interrupt pin. After all interrupts have been determined and processed, the interrupt
hander routine should restore the state of the IMRx registers.
7.5 Status Registers
When a particular event or condition has occurred (or is still occurring in the case of conditions), the
appropriate bit in a status register will be set to a one. All the status registers operate in a latched fashion,
which means that if an event or condition occurs a bit is set to a one. It will remain set until the user reads
that bit. An event bit will be cleared when it is read and it will not be set again until the event has
occurred again. Condition bits such as RLOS, etc., will remain set if the alarm is still present.
The user will always precede a read of any of the status registers with a write. The byte written to the
register will inform the DS26502 which bits the user wishes to read and have cleared. The user will write
a byte to one of these registers, with a one in the bit positions he or she wishes to read and a zero in the
bit positions he or she does not wish to obtain the latest information on. When a one is written to a bit
location, the read register will be updated with the latest information. When a zero is written to a bit
position, the read register will not be updated and the previous value will be held. A write to the status
registers will be immediately followed by a read of the same register. This write-read scheme allows an
external microcontroller or microprocessor to individually poll certain bits without disturbing the other
bits in the register. This operation is key in controlling the DS26502 with higher-order languages.
Status register bits are divided into two groups: condition bits and event bits. Condition bits are typically
network conditions such as loss of frame, or all-ones detect. Event bits are typically markers such as the
one-second timer. Each status register bit is labeled as a condition or event bit. Some of the status
registers have bits for both the detection of a condition and the clearance of the condition. For example,
SR2 has a bit that is set when the device goes into a loss of frame state (SR2.0, a condition bit) and a bit
that is set (SR2.4, an event bit) when the loss of frame condition clears (goes in sync). Some of the status
register bits (condition bits) do not have a separate bit for the “condition clear” event but rather the status
bit can produce interrupts on both edges, setting, and clearing. These bits are marked as “double interrupt
bits.” An interrupt will be produced when the condition occurs and when it clears.
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7.6 Information Registers
Information registers operate the same as status registers except they cannot cause interrupts. INFO3
register is a read-only register and it reports the status of the E1 synchronizer in real time. INFO3
information bits are not latched, and it is not necessary to precede a read of these bits with a write.
7.7 Interrupt Information Registers
The Interrupt Information Registers provide an indication of which Status Registers (SR1 through SR4)
are generating an interrupt. When an interrupt occurs, the host can read IIR to quickly identify which of
the three status registers are causing the interrupt.
Register Name: IIR
Register Description: Interrupt Information Register
Register Address: 13h
Bit # 7 6 5 4 3 2 1 0
Name — — — — SR4 SR3 SR2 SR1
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Status Register 1 (SR1)
0 = Status Register 1 interrupt not active.
1 = Status Register 1 interrupt active.
Bit 1: Status Register 2 (SR2)
0 = Status Register 1 interrupt not active.
1 = Status Register 1 interrupt active.
Bit 2: Status Register 3 (SR3)
0 = Status Register 1 interrupt not active.
1 = Status Register 1 interrupt active.
Bit 3: Status Register 4 (SR4)
0 = Status Register 1 interrupt not active.
1 = Status Register 1 interrupt active.
Bits 4 to 7: Unused
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8. T1 FRAMER/FORMATTER CONTROL REGISTERS
The T1 framer portion of the DS26502 is configured via a set of five control registers. Typically, the
control registers are only accessed when the system is first powered up. Once the DS26502 has been
initialized, the control registers will only need to be accessed when there is a change in the system
configuration. There are two receive control registers (T1RCR1 and T1RCR2), two transmit control
registers (T1TCR1 and T1TCR2), and a common control register (T1CCR). Each of these registers is
described in this section.
8.1 T1 Control Registers
Register Name: T1RCR1
Register Description: T1 Receive Control Register 1
Register Address: 03h
Bit # 7 6 5 4 3 2 1 0
Name — ARC OOF1 OOF2 SYNCC SYNCT SYNCE RESYNC
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Resynchronize (RESYNC). When toggled from low to high, a resynchronization of the receive side framer is initiated.
Must be cleared and set again for a subsequent resync.
Bit 1: Sync Enable (SYNCE)
0 = auto resync enabled
1 = auto resync disabled
Bit 2: Sync Time (SYNCT)
0 = qualify 10 bits
1 = qualify 24 bits
Bit 3: Sync Criteria (SYNCC)
In D4 Framing Mode:
0 = search for Ft pattern, then search for Fs pattern
1 = cross couple Ft and Fs pattern
In ESF Framing Mode:
0 = search for FPS pattern only
1 = search for FPS and verify with CRC6
Bits 4 and 5: Out Of Frame Select Bits (OOF2, OOF1)
OOF2 OOF1 Out Of Frame Criteria
0 0 2/4 frame bits in error
0 1 2/5 frame bits in error
1 0 2/6 frame bits in error
1 1 2/6 frame bits in error
Bit 6: Auto Resync Criteria (ARC)
0 = resync on OOF or RLOS event
1 = resync on OOF only
Bit 7: Unused, must be set = 0 for proper operation.
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Register Name: T1RCR2
Register Description: T1 Receive Control Register 2
Register Address: 04h
Bit # 7 6 5 4 3 2 1 0
Name — — RB8ZS — — — RJC RD4YM
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0
HBE
PIN55 0 0 0 0 0
Bit 0: Receive Side D4 Yellow Alarm Select (RD4YM)
0 = zeros in bit 2 of all channels
1 = a one in the S-bit position of frame 12 (J1 Yellow Alarm Mode)
Bit 1: Receive Japanese CRC6 Enable (RJC)
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)
1 = use Japanese standard JT–G704 CRC6 calculation
Bits 2 to 4, 6, 7: Unused, must be set = 0 for proper operation.
Bit 5: Receive B8ZS Enable (RB8ZS)
0 = B8ZS disabled
1 = B8ZS enabled
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Register Name: T1TCR1
Register Description: T1 Transmit Control Register 1
Register Address: 05h
Bit # 7 6 5 4 3 2 1 0
Name TJC TFPT TCPT — — — — TYEL
Default 0 0 0 0 0 0 0 0
HW
Mode
RMODEx
PINS 0 0 0 0 0 0 0
Bit 0:Transmit Yellow Alarm (TYEL)
0 = do not transmit yellow alarm
1 = transmit yellow alarm
Bits 1 to 4: Unused, must be set = 0 for proper operation.
Bit 5: Transmit CRC Pass-Through (TCPT)
0 = source CRC6 bits internally
1 = CRC6 bits sampled at TSER during F-bit time
Bit 6: Transmit F-Bit Pass-Through (TFPT)
0 = F bits sourced internally
1 = F bits sampled at TSER
Bit 7: Transmit Japanese CRC6 Enable (TJC)
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)
1 = use Japanese standard JT–G704 CRC6 calculation
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Register Name: T1TCR2
Register Description: T1 Transmit Control Register 2
Register Address: 06h
Bit # 7 6 5 4 3 2 1 0
Name TB8ZS TFSE — FBCT2 FBCT1 TD4YM — TB7ZS
Default 0 1 0 0 0 0 0 0
HW
Mode
HBE
PIN 55 1 0 0 0 0 0 0
Bit 0: Transmit-Side Bit 7 Zero-Suppression Enable (TB7ZS)
0 = no stuffing occurs
1 = bit 7 forced to a 1 in channels with all 0s
Bits 1 and 5: Unused, must be set = 0 for proper operation.
Bit 2: Transmit-Side D4 Yellow Alarm Select (TD4YM)
0 = 0s in bit 2 of all channels
1 = a 1 in the S-bit position of frame 12
Bit 3: F-Bit Corruption Type 1 (FBCT1). A low-to-high transition of this bit causes the next three consecutive Ft (D4
framing mode) or FPS (ESF framing mode) bits to be corrupted causing the remote end to experience a loss of frame (loss of
synchronization).
Bit 4: F-Bit Corruption Type 2 (FBCT2). Setting this bit high enables the corruption of one Ft (D4 framing mode) or FPS
(ESF framing mode) bit in every 128 Ft or FPS bits as long as the bit remains set.
Bit 6: Transmit Fs-Bit Insertion Enable (TFSE). Only set this bit to a 1 in D4 framing applications. Must be set to 1 to
source the Fs pattern from the TFDL register. In all other modes this bit must be set = 0.
0 = Fs-bit insertion disabled
1 = Fs-bit insertion enabled
Bit 7: Transmit B8ZS Enable (TB8ZS)
0 = B8ZS disabled
1 = B8ZS enabled
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Register Name: T1CCR
Register Description: T1 Common Control Register
Register Address: 07h
Bit # 7 6 5 4 3 2 1 0
Name — — — TRAI-CI TAIS-CI — PDE —
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bits 0, 2, 5 to 7: Unused, must be set = 0 for proper operation.
Bit 1: Pulse-Density Enforcer Enable (PDE). The framer always examines the transmit and receive data streams for
violations of these, which are required by ANSI T1.403: No more than 15 consecutive zeros and at least N ones in each and
every time window of 8 x (N + 1) bits, where N = 1 through 23. When this bit is set to one, the DS26502 forces the transmitted
stream to meet this requirement no matter the content of the transmitted stream. When running B8ZS, this bit should be set to
zero, as B8ZS encoded data streams cannot violate the pulse-density requirements.
0 = disable transmit pulse-density enforcer
1 = enable transmit pulse-density enforcer
Bit 3: Transmit AIS-CI Enable (TAIS-CI). Setting this bit causes the AIS-CI code to be transmitted from the framer to the
LIU, as defined in ANSI T1.403.
0 = do not transmit the AIS-CI code
1 = transmit the AIS-CI code
Bit 4: Transmit RAI-CI Enable (TRAI-CI). Setting this bit causes the ESF RAI-CI code to be transmitted in the FDL bit
position.
0 = do not transmit the ESF RAI-CI code
1 = transmit the ESF RAI-CI code
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Table 8-1. T1 Alarm Criteria
ALARM SET CRITERIA CLEAR CRITERIA
Blue Alarm (AIS) (Note 1) Over a 3ms window, five or
fewer zeros are received
Over a 3ms window, six or more zeros
are received
Yellow Alarm (RAI)
D4 Bit-2 Mode (T1RCR2.0 = 0)
D4 12th F-bit Mode (T1RCR2.0
= 1; this mode is also referred to
as the “Japanese Yellow Alarm”)
ESF Mode
Bit 2 of 256 consecutive
channels is set to zero for at
least 254 occurrences
12th framing bit is set to one
for two consecutive
occurrences
16 consecutive patterns of
00FF appear in the FDL
Bit 2 of 256 consecutive channels is
set to zero for less than 254
occurrences
12th framing bit is set to zero for two
consecutive occurrences
14 or fewer patterns of 00FF hex out of
16 possible appear in the FDL
Red Alarm (RLOS) (Also
referred to as Loss Of Signal)
192 consecutive zeros are
received
14 or more ones out of 112 possible bit
positions are received, starting with the
first one received
Note: The definition of Blue Alarm (or Alarm Indication Signal) is an unframed, all-ones signal. Blue Alarm detectors should be able to
operate properly in the presence of a 10E-3 error rate, and they should not falsely trigger on a framed, all-ones signal. The Blue Alarm
criteria in the DS26502 has been set to achieve this performance.
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9. E1 FRAMER/FORMATTER CONTROL REGISTERS
The E1 framer portion of the DS26502 is configured via a set of two control registers. Typically, the
control registers are only accessed when the system is first powered up. Once the DS26502 has been
initialized, the control registers will only need to be accessed when there is a change in the system
configuration. There is one receive control register (E1RCR) and one transmit control register (E1TCR).
There are also two information registers and a status register, as well as an interrupt mask register. Each
of these registers is described in this section.
9.1 E1 Control Registers
Register Name: E1RCR
Register Description: E1 Receive Control Register
Register Address: 1Dh
Bit # 7 6 5 4 3 2 1 0
Name — RLOSA RHDB3 — — FRC SYNCE RESYNC
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0
HBE
PIN 55 0 0 0 0 0
Bit 0: Resync (RESYNC). When toggled from low to high, a resync is initiated. Must be cleared and set again for a
subsequent resync.
Bit 1: Sync Enable (SYNCE)
0 = auto resync enabled
1 = auto resync disabled
Bit 2: Frame Resync Criteria (FRC)
0 = resync if FAS received in error three consecutive times
1 = resync if FAS or bit 2 of non-FAS is received in error three consecutive times
Bits 3, 4, 7: Unused, must be set = 0 for proper operation.
Bit 5: Receive HDB3 Enable (RHDB3)
0 = HDB3 disabled
1 = HDB3 enabled
Bit 6: Receive Loss Of Signal (RLOS) Alternate Criteria (RLOSA). Defines the criteria for a Receive Loss Of Signal
condition.
0 = RLOS declared upon 255 consecutive zeros (125µs)
1 = RLOS declared upon 2048 consecutive zeros (1ms)
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Table 9-1. E1 Sync/Resync Criteria
FRAME OR
MULTIFRAME
LEVEL
SYNC CRITERIA RESYNC CRITERIA ITU SPEC.
FAS FAS present in frame N and
N + 2, and FAS not present in
frame N + 1
Three consecutive incorrect FAS
received
Alternate: (E1RCR.2 = 1) The above
criteria is met or three consecutive
incorrect bit 2 of non-FAS received
G.706
4.1.1
4.1.2
CRC4 Two valid MF alignment
words found within 8ms
915 or more CRC4 code words out of
1000 received in error
G.706
4.2 and 4.3.2
CAS Valid MF alignment word
found and previous time slot
16 contains code other than
all zeros
Two consecutive MF alignment
words received in error
G.732 5.2
Register Name: E1TCR
Register Description: E1 Transmit Control Register
Register Address: 1Eh
Bit # 7 6 5 4 3 2 1 0
Name TFPT — — TSiS — — THDB3 —
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0
HBE
PIN 55 0
Bits 0, 2, 3, 5, 6:Unused, must be set = 0 for proper operation.
Bit 1: Transmit HDB3 Enable (THDB3)
0 = HDB3 disabled
1 = HDB3 enabled
Bit 4: Transmit International Bit Select (TSiS)
0 = sample Si bits at TSER pin
1 = source Si bits from TAF and TNAF registers (in this mode, E1TCR1.7 must be set to 0)
Bit 7: Transmit Time Slot 0 Pass-Through (TFPT)
0 = FAS bits/Sa bits/remote alarm sourced internally from the TAF and TNAF registers
1 = FAS bits/Sa bits/remote alarm sourced from TSER
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9.2 E1 Information Registers
Register Name: INFO2
Register Descript i on: Information Register 2
Register Address: 12h
Bit # 7 6 5 4 3 2 1 0
Name — — — — — CRCRC FASRC CASRC
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: CAS Resync Criteria Met Event (C ASRC). Set when two consecutive CAS MF alignment words are received in
error.
Bit 1: FAS Resync Criteria Met Event (F AS RC . Set when three consecutive FAS words are received in error.
Bit 2: CRC Resync Criteria Met Event (CRCRC). Set when 915/1000 codewords are received in error.
Bits 3 to 7: Unused
Register Name: INFO3
Register Descript i on: Information Register 3 (Real Time)
Register Address: 1Ch
Bit # 7 6 5 4 3 2 1 0
Name CSC5 CSC4 CSC3 CSC2 CSC0 FASSA CASSA CRC4SA
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: CRC4 MF Sync Active (C RC 4S A ). Set while the synchronizer is searching for the CRC4 MF alig nment word.
Bit 1: CAS MF Sync Active (CASSA). Set while the synchronizer is searching for the CAS MF alignment word.
Bit 2: FAS Sync Active (FASSA). Set while the synchronizer is searching for alignment at the FAS level.
Bits 3 to 7: CRC4 Sync Counter Bits (CSC0 and CSC2 to CSC5). The CRC4 sync counter increments each time the 8ms-
CRC4 multiframe search times out. The counter is cleared when the framer has successfully obtained synchronization at the
CRC4 level. The counter can also be cleared by disabling CRC4 mode. This counter is useful for determining the amount of
time the framer has been searching for synchronization at the CRC4 level. ITU G.706 suggests that if synchronization at the
CRC4 level cannot be obtained within 400ms, then the search should be abandoned and proper action taken. The CRC4 sync
counter will rollover. CSC0 is the LSB of the 6-bit coun ter. (Note: The second LSB, CSC1, is not accessible. CSC1 is omitted
to allow resolution to >400ms using 5 bits.)
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Table 9-2. E1 Alarm Criteria
ALARM SET CRITERIA CLEAR CRITERIA ITU
SPEC.
RLOF An RLOF condition exists on power-up
prior to initial synchronization, when a
resync criteria has been met, or when a
manual resync has been initiated via
E1RCR.0
RLOS
255 or 2048 consecutive zeros received as
determined by E1RCR.0
In 255-bit times, at least 32
ones are received
G.775/G.962
RRA Bit 3 of non-align frame set to one for
three consecutive occasions
Bit 3 of non-align frame set to
zero for three consecutive
occasions
O.162
2.1.4
RUA1 Fewer than three zeros in two frames (512
bits)
More than two zeros in two
frames (512 bits)
O.162
1.6.1.2
RDMA Bit 6 of time slot 16 in frame 0 has been
set for two consecutive multiframes
V52LNK Two out of three Sa7 bits are zero G.965
Register Name: IDR
Register Description: Device Identification Register
Register Address: 10h
Bit # 7 6 5 4 3 2 1 0
Name ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0
Default 0 0 0 0 N N N N
HW
Mode X X X X X X X X
Bits 0 to 3: Chip Revision Bits (ID0 to ID3). The lower four bits of the IDR are used to display the die revision of the chip.
ID0 is the LSB of a decimal code that represents the chip revision.
Bits 4 to 7: Device ID (ID4 to ID7). The upper four bits of the IDR are used to display the DS26502 ID. The DS26502 ID is
0000.
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Register Name: SR2
Register Description: Status Register 2
Register Address: 16h
Bit # 7 6 5 4 3 2 1 0
Name RYELC RAISC RLOSC RLOFC RYEL RAIS RLOS RLOF
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X
RAIS
PIN 29
RLOS
PIN 32
LOF
PIN 30
Bit 0: Receive Loss of Frame Condition (RLOF). Set when the DS26502 is not synchronized to the received data stream.
Bit 1: Receive Loss Of Signal Condition (RLOS). Set when 255 (or 2048 if E1RCR.6 = 1) E1 mode or 192 T1 mode
consecutive zeros have been detected. In 6312kHz Synchronization Interface Mode, this bit will be set when the signal
received is out of range as defined by the G.703 Appendix II specification.
Bit 2: Receive Alarm Indication Signal (T1= Blue Alarm, E1= AIS) Condition (RAIS). Set when an unframed all-ones
code is received.
Bit 3: Receive Yellow Alarm Condition (RYEL). (T1 only) Set when a yellow alarm is received.
Bit 4: Receive Loss of Frame Clear Event (RLOFC). Set when the framer achieves synchronization; will remain set until
read.
Bit 5: Receive Loss Of Signal Clear Event (RLOSC). Set when loss of signal condition is no longer detected.
Bit 6: Receive Alarm Indication Signal Clear Event (RAISC). Set when the unframed all-ones condition is no longer
detected.
Bit 7: Receive Yellow Alarm Clear Event (RYELC). (T1 only) Set when the yellow alarm condition is no longer detected.
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Register Name: IMR2
Register Description: Interrupt Mask Register 2
Register Address: 17h
Bit # 7 6 5 4 3 2 1 0
Name RYELC RAISC RLOSC RLOFC RYEL RAIS RLOS RLOF
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Receive Loss of Frame Condition (RLOF)
0 = interrupt masked
1 = interrupt enabled–interrupts on rising edge only
Bit 1: Receive Loss Of Signal Condition (RLOS)
0 = interrupt masked
1 = interrupt enabled–interrupts on rising edge only
Bit 2: Receive Alarm Indication Signal Condition (RAIS)
0 = interrupt masked
1 = interrupt enabled–interrupts on rising edge only
Bit 3: Receive Yellow Alarm Condition (RYEL)
0 = interrupt masked
1 = interrupt enabled–interrupts on rising edge only
Bit 4: Receive Loss of Frame Clear Event (RLOFC)
0 = interrupt masked
1 = interrupt enabled
Bit 5: Receive Loss Of Signal Condition Clear (RLOSC)
0 = interrupt masked
1 = interrupt enabled
Bit 6: Receive Alarm Indication Signal Clear Event (RAISC)
0 = interrupt masked
1 = interrupt enabled
Bit 7: Receive Yellow Alarm Clear Event (RYELC)
0 = interrupt masked
1 = interrupt enabled
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10. I/O PIN CONFIGURATION OPTIONS
Register Name: IOCR1
Register Description: I/O Configuration Register 1
Register Address: 01h
Bit # 7 6 5 4 3 2 1 0
Name — RSMS2 RSMS1 RLOFF
CSM_TSDW TSM TSIO ODF
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0
RSM
PIN 1 0 0
TSM
PIN 2 0 0
Bit 0: Output Data Format (ODF)
0 = bipolar data at TPOS and TNEG
1 = NRZ data at TPOS; TNEG = 0
Bit 1: TS_8K_4 I/O Select (TSIO). This bit determines whether the TS_8K_4 pin is an input or and output. See Table 10-1.
0 = TS_8K_4 is an input
1 = TS_8K_4 is an output
Bit 2: TS_8K_4 Mode Select (TSM). In T1 or E1 operation, selects frame or multiframe mode for the TS_8K_4 pin. In
6312kHz or 64KCC mode, this bit should be set = 0. See Table 10-1.
0 = frame mode
1 = multiframe mode
Bit 3: Composite Clock Sync Mode_ Transmit Signaling Double-Wide Sync (CSM_TSDW). In 64 kHz Composite Clock
mode, this bit determines whether the TS_8K_4 pin is an 8kHz or a 400Hz reference input (TS_8K_4 pin in input mode,
IOCR1 = 0), or an 8kHz or 400Hz reference output (TS_8K_4 pin in output mode, IOCR1 = 1). In T1 mode, setting this bit =
1 and setting TSIO = 1 will cause the sync pulse output on TS_8K_4 to be two clocks wide during signaling frames. In E1 or
6312kHz mode this bit should be set = 0. See Table 10-1.
0 = (CC64K) 8kHz reference, (T1) normal sync pulses
1 = (CC64K) 400Hz reference, (T1) double-wide sync pulses during signaling frames
Bit 4: RLOF_CCE Output Function (RLOFF). In T1 or E1 receive mode this bit determines the function of the
RLOF_CCE pin. In 64KCC or 6312kHz receive mode, this bit should be set = 0.
0 = receive loss of frame (RLOF)
1 = loss-of-transmit clock (LOTC)
Bit 5: RS_8K Mode Select 1(RSMS1). In T1 or E1 receive mode, this bit selects a frame or multiframe output pulse at
RS_8K pin. IOCR.6 may be used to select other function for the RS_8K pin.
0 = frame mode
1 = multiframe mode
Bit 6: RS_8K Mode Select 2 (RSMS2). In T1 and E1 receive mode, this bit along with IOCR.5 selects the function of the
RS_8K pin.
T1 Mode: (when IOCR.5 set = 0)
0 = do not pulse double-wide in signaling frames
1 = do pulse double-wide in signaling frames
E1 Mode: (when IOCR.5 set = 1)
0 = RS_8K outputs CAS multiframe boundaries
1 = RS_8K outputs CRC4 multiframe boundaries
Bit 7: Unused, must be set = 0 for proper operation.
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Table 10-1. TS_8K_4 Pin Functions
TRANSMIT
MODE IOCR1.3 IOCR1.2 IOCR1.1 TS_8K_4
FUNCTION
T1/E1 0 0 0 Frame sync input
T1/E1 0 0 1 Frame sync output
T1/E1 0 1 0 Multiframe sync input
T1/E1 0 1 1 Multiframe sync output
64KCC 0 0 0 8kHz input reference
64KCC 0 0 1 8kHz output reference
64KCC 1 0 0 400Hz input reference
64KCC 1 0 1 400Hz output reference
Table 10-2. RLOF_CCE Pin Functions
RECEIVE
MODE IOCR1.4 RLOF_CCE PIN FUNCTION
T1/E1 0 Indicate loss of frame
T1/E1 1 Indicates loss of transmit clock
64KCC 0 Indicates composite clock error
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Register Name: IOCR2
Register Description: I/O Configuration Register 2
Register Address: 02h
Bit # 7 6 5 4 3 2 1 0
Name RCLKINV TCLKINV RS_8KINV TS_8K_4INV — — — —
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bits 0 to 3: Unused, must be set = 0 for proper operation.
Bit 4: TS_8K_4 Invert (TS_8K_4INV)
0 = no inversion
1 = invert
Bit 5: RS_8K Invert (RS_8KINV)
0 = no inversion
1 = invert
Bit 6: TCLK Invert (TCLKINV)
0 = no inversion
1 = invert
Bit 7: RCLK Invert (RCLKINV)
0 = no inversion
1 = invert
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11. T1 SYNCHRONIZATION STATUS MESSAGE
The DS26502 has a BOC controller to handle SSM services in T1 mode.
Table 11-1. T1 SSM Messages
QUALITY
LEVEL DESCRIPTION BOC CODE
1 Stratum 1 Traceable 0000010011111111
2 Synchronized Traceablity Unknown 0000100011111111
3 Stratum 2 Traceable 0000110011111111
4 Stratum 3 Traceable 0001000011111111
5 SONET Minimum Clock Traceable 0010001011111111
6 Stratum 4 Traceable 0010100011111111
7 Do Not Use For Synchronization 0011000011111111
User Assignable Reserved For Network Synchronization Use 0100000011111111
11.1 T1 Bit-Oriented Code (BOC) Controller
The DS26502 contains a BOC generator on the transmit side and a BOC detector on the receive side. The
BOC function is available only in T1 mode. In typical BITS applications, the BOC controller would be
used to transmit and receive Synchronization Status Messages in T1 mode over the data link.
11.2 Transmit BOC
Bits 0 through 5 in the TFDL register contain the BOC or synchronization status message to be
transmitted. Setting BOCC.0 = 1 causes the transmit BOC controller to immediately begin inserting the
BOC sequence into the FDL bit position. The transmit BOC controller automatically provides the abort
sequence. BOC messages will be transmitted as long as BOCC.0 is set. TFSE (T1TCR2.6) must be set =
0 when using the transmit BOC function.
To transmit a BOC, use the following:
1) Write 6-bit code into the TFDL register.
2) Set SBOC bit in BOCC register = 1.
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11.3 Receive BOC
The receive BOC function is enabled by setting BOCC.4 = 1. The RFDL register will now operate as the
receive BOC message and information register. The lower six bits of the RFDL register (BOC message
bits) are preset to all ones. When the BOC bits change state, the BOC change of state indicator, SR3.0
will alert the host. The host will then read the RFDL register to get the BOC message. A change of state
will occur when either a new BOC code has been present for time determined by the receive BOC filter
bits, RBF0 and RBF1, in the BOCC register.
To receive a BOC, use the following:
1) Set integration time via BOCC.1 and BOCC.2.
2) Enable the receive BOC function (BOCC.4 = 1).
3) Enable interrupt (IMR3.0 = 1).
4) Wait for interrupt to occur.
5) Read the RFDL register.
6) The lower six bits of the RFDL register is the message.
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Register Name: BOCC
Register Description: BOC Control Register
Register Address: 1Fh
Bit # 7 6 5 4 3 2 1 0
Name — — — RBOCE RBR RBF1 RBF0 SBOC
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Send BOC (SBOC). Set = 1 to transmit the BOC code placed in bits 0 to 5 of the TFDL register.
Bits 1 and 2: Receive BOC Filter Bits (RBF0, RBF1). The BOC filter sets the number of consecutive patterns that must be
received without error prior to an indication of a valid message.
RBF1 RBF0 CONSECUTIVE BOC CODES FOR VALID
SEQUENCE IDENTIFICATION
0 0 None
0 1 3
1 0 5
1 1 7
Bit 3: Receive BOC Reset (RBR). A 0-to-1 transition will reset the BOC circuitry. Must be cleared and set again for a
subsequent reset.
Bit 4: Receive BOC Enable (RBOCE). Enables the receive BOC function. The RFDL register will report the received BOC
code.
0 = receive BOC function disabled
1 = receive BOC function enabled. The RFDL register will report BOC messages
Bits 5 to 7: Unused, must be set = 0 for proper operation.
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Register Name: RFDL (RFDL register bit usage when BOCC.4 = 1)
Register Description: Receive FDL Register
Register Address: 50h
Bit # 7 6 5 4 3 2 1 0
Name — — RBOC5 RBOC4 RBOC3 RBOC2 RBOC1 RBOC0
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: BOC Bit 0 (RBOC0)
Bit 1: BOC Bit 1 (RBOC1)
Bit 2: BOC Bit 2 (RBOC2)
Bit 3: BOC Bit 3 (RBOC3)
Bit 4: BOC Bit 4 (RBOC4)
Bit 5: BOC Bit 5 (RBOC5)
Bits 6 and 7: This bit position is unused when BOCC.4 = 1.
Register Name: RFDLM1, RFDLM2
Register Description: Receive FDL Match Register 1
Receive FDL Match Register 2
Register Address: 52h, 53h
Bit # 7 6 5 4 3 2 1 0
Name RFDLM7 RFDLM6 RFDLM5 RFDLM4 RFDLM3 RFDLM2 RFDLM1 RFDLM0
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Receive FDL Match Bit 0 (RFDLM0). LSB of the FDL Match Code.
Bit 1: Receive FDL Match Bit 1 (RFDLM1)
Bit 2: Receive FDL Match Bit 2 (RFDLM2)
Bit 3: Receive FDL Match Bit 3 (RFDLM3)
Bit 4: Receive FDL Match Bit 4 (RFDLM4)
Bit 5: Receive FDL Match Bit 5 (RFDLM5)
Bit 6: Receive FDL Match Bit 6 (RFDLM6)
Bit 7: Receive FDL Match Bit 7 (RFDLM7). MSB of the FDL Match Code.
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Register Name: SR3
Register Description: Status Register 3
Register Address: 18h
Bit # 7 6 5 4 3 2 1 0
Name RAIS-CI LOTC BOCC RFDLAD RFDLF TFDLE RMTCH RBOC
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Receive BOC Detector Change-of-State Event (RBOC). Set whenever the BOC detector sees a change of state to a
valid BOC. The setting of this bit prompts the user to read the RFDL register.
Bit 1: Receive FDL Match Event (RMTCH). Set whenever the contents of the RFDL register matches RFDLM1 or
RFDLM2.
Bit 2: TFDL Register Empty Event (TFDLE). Set when the transmit FDL buffer (TFDL) empties.
Bit 3: RFDL Register Full Event (RFDLF). Set when the receive FDL buffer (RFDL) fills to capacity.
Bit 4: RFDL Abort Detect Event (RFDLAD). Set when eight consecutive ones are received on the FDL.
Bit 5: BOC Clear Event (BOCC). Set when 30 FDL bits occur without an abort sequence.
Bit 6: Loss Of Transmit Clock Event (LOTC). Set when the signal at the TCLK pin has not transitioned for approximately
15 periods of the scaled MCLK.
Bit 7: Receive AIS-CI Event (RAIS-CI). (T1 Only) Set when the receiver detects the AIS-CI pattern as defined in ANSI
T1.403.
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Register Name: IMR3
Register Description: Interrupt Mask Register 3
Register Address: 19h
Bit # 7 6 5 4 3 2 1 0
Name RAIS-CI LOTC BOCC RFDLAD RFDLF TFDLE RMTCH RBOC
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Receive BOC Detector Change-of-State Event (RBOC)
0 = interrupt masked
1 = interrupt enabled
Bit 1: Receive FDL Match Event (RMTCH)
0 = interrupt masked
1 = interrupt enabled
Bit 2: TFDL Register Empty Event (TFDLE)
0 = interrupt masked
1 = interrupt enabled
Bit 3: RFDL Register Full Event (RFDLF)
0 = interrupt masked
1 = interrupt enabled
Bit 4: RFDL Abort Detect Event (RFDLAD)
0 = interrupt masked
1 = interrupt enabled
Bit 5: BOC Clear Event (BOCC).
0 = interrupt masked
1 = interrupt enabled
Bit 6: Loss Of Transmit Clock Event (LOTC)
0 = interrupt masked
1 = interrupt enabled
Bit 7: Receive AIS-CI Event (RAIS-CI)
0 = interrupt masked
1 = interrupt enabled
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Register Name: SR4
Register Description: Status Register 4
Register Address: 1Ah
Bit # 7 6 5 4 3 2 1 0
Name — RSA1 RSA0 TMF TAF RMF RCMF RAF
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Receive Align Frame Event (RAF). (E1 only) Set every 250µs at the beginning of align frames. Used to alert the host
that Si and Sa bits are available in the RAF and RNAF registers.
Bit 1: Receive CRC4 Multiframe Event (RCMF). (E1 only) Set on CRC4 multiframe boundaries; will continue to be set
every 2ms on an arbitrary boundary if CRC4 is disabled.
Bit 2: Receive Multiframe Event (RMF)
E1 Mode: Set every 2ms (regardless if CAS signaling is enabled or not) on receive multiframe boundaries. Used to
alert the host that signaling data is available.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 3: Transmit Align Frame Event (TAF). (E1 only) Set every 250µs at the beginning of align frames. Used to alert the host
that the TAF and TNAF registers need to be updated.
Bit 4: Transmit Multiframe Event (TMF)
E1 Mode: Set every 2ms (regardless if CRC4 is enabled) on transmit multiframe boundaries. Used to alert the host
that signaling data needs to be updated.
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.
Bit 5: Receive Signaling All Zeros Event (RSA0). (E1 only) Set when over a full MF, time slot 16 contains all zeros.
Bit 6: Receive Signaling All Ones Event (RSA1). (E1 only) Set when the contents of time slot 16 contains fewer than three
zeros over 16 consecutive frames. This alarm is not disabled in the CCS signaling mode.
Bit 7: Unused
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Register Name: IMR4
Register Description: Interrupt Mask Register 4
Register Address: 1Bh
Bit # 7 6 5 4 3 2 1 0
Name — RSA1 RSA0 TMF TAF RMF RCMF RAF
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Receive Align Frame Event (RAF)
0 = interrupt masked
1 = interrupt enabled
Bit 1: Receive CRC4 Multiframe Event (RCMF)
0 = interrupt masked
1 = interrupt enabled
Bit 2: Receive Multiframe Event (RMF)
0 = interrupt masked
1 = interrupt enabled
Bit 3: Transmit Align Frame Event (TAF)
0 = interrupt masked
1 = interrupt enabled
Bit 4: Transmit Multiframe Event (TMF)
0 = interrupt masked
1 = interrupt enabled
Bit 5: Receive Signaling All Zeros Event (RSA0)
0 = interrupt masked
1 = interrupt enabled
Bit 6: Receive Signaling All Ones Event (RSA1)
0 = interrupt masked
1 = interrupt enabled
Bit 7: Unused, must be set = 0 for proper operation.
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Register Name: TFDL
Register Description: Transmit FDL Register
Register Address: 51h
Bit # 7 6 5 4 3 2 1 0
Name TFDL7 TFDL6 TFDL5 TFDL4 TFDL3 TFDL2 TFDL1 TFDL0
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 1 1 1 0 0
Note: Also used to insert Fs framing pattern in D4 framing mode.
The transmit FDL register (TFDL) contains the FDL information that is to be inserted on a byte-basis into the outgoing T1 data
stream. The LSB is transmitted first.
Bit 0: Transmit FDL Bit 0 (TFDL0). LSB of the transmit FDL code.
Bit 1: Transmit FDL Bit 1 (TFDL1)
Bit 2: Transmit FDL Bit 2 (TFDL2)
Bit 3: Transmit FDL Bit 3 (TFDL3)
Bit 4: Transmit FDL Bit 4 (TFDL4)
Bit 5: Transmit FDL Bit 5 (TFDL5)
Bit 6: Transmit FDL Bit 6 (TFDL6)
Bit 7: Transmit FDL Bit 7 (TFDL7). MSB of the transmit FDL code.
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12. E1 SYNCHRONIZATION STATUS MESSAGE
The DS26502 provides access to both the transmit and receive Sa/Si bits. In E1, the Sa bits are used to
transmit and receive the SSM. The primary method to access the Sa (and Si) bits is based on CRC4
multiframe access. An alternate method is based on double-frame access.
Table 12-1. E1 SSM Messages
QUALITY
LEVEL DESCRIPTION Sa BIT
MESSAGE
0 Quality unknown (existing sync network) 0000
1 Reserved 0001
2 Rec. G.811 (Traceable to PRS) 0010
3 Reserved 0011
4 SSU-A (Traceable to SSU type A, see G.812) 0100
5 Reserved 0101
6 Reserved 0110
7 Reserved 0111
8 SSU-B (Traceable to SSU type B, see G.812) 1000
9 Reserved 1001
10 Reserved 1010
11 Synchronous Equipment Timing Source 1011
12 Reserved 1100
13 Reserved 1101
14 Reserved 1110
15 Do not use for synchronization 01111
In E1 operation, SSMs are transmitted using one of the Sa bits—Sa4, Sa5, Sa6, Sa7, or Sa8. The SSM is
transmitted MSB first in the first frame of the multiframe. Each multiframe will contain two SSMs, one in
each sub-multiframe. An SSM is declared valid when the message in three sub-multiframes are alike.
12.1 Sa/Si Bit Access Based on CRC4 Multiframe
On the receive side, there is a set of eight registers (RSiAF, RSiNAF, RRA, RSa4 to RSa8) that report the
Si and Sa bits as they are received. These registers are updated on CRC4 multiframes. A bit in status
register 4 (SR4.1) indicates the multiframe boundary. The host can use the SR4.1 bit to know when to
read these registers. The user has 2ms to retrieve the data before it is lost. The MSB of each register is the
first received. See the following register descriptions for more details.
On the transmit side, there is also a set of eight registers (TSiAF, TSiNAF, TRA, TSa4 to TSa8) that, via
the transmit Sa bit control register (TSaCR), can be programmed to insert both Si and Sa data. Data is
sampled from these registers with the setting of the transmit multiframe bit in status register 2 (SR4.4).
The host can use the SR4.4 bit to know when to update these registers. It has 2ms to update the data or
else the old data will be retransmitted. The MSB of each register is the first bit transmitted. See the
following register descriptions for details.
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Register Name: RSiAF
Register Description: Receive Si Bits of the Align Frame
Register Address: 58h
Bit # 7 6 5 4 3 2 1 0
Name SiF0 SiF2 SiF4 SiF6 SiF8 SiF10 SiF12 SiF14
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Si Bit of Frame 14(SiF14)
Bit 1: Si Bit of Frame 12(SiF12)
Bit 2: Si Bit of Frame 10(SiF10)
Bit 3: Si Bit of Frame 8(SiF8)
Bit 4: Si Bit of Frame 6(SiF6)
Bit 5: Si Bit of Frame 4(SiF4)
Bit 6: Si Bit of Frame 2(SiF2)
Bit 7: Si Bit of Frame 0(SiF0)
Register Name: RSiNAF
Register Description: Receive Si Bits of the Non-Align Frame
Register Address: 59h
Bit # 7 6 5 4 3 2 1 0
Name SiF1 SiF3 SiF5 SiF7 SiF9 SiF11 SiF13 SiF15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Si Bit of Frame 15(SiF15)
Bit 1: Si Bit of Frame 13(SiF13)
Bit 2: Si Bit of Frame 11(SiF11)
Bit 3: Si Bit of Frame 9(SiF9)
Bit 4: Si Bit of Frame 7(SiF7)
Bit 5: Si Bit of Frame 5(SiF5)
Bit 6: Si Bit of Frame 3(SiF3)
Bit 7: Si Bit of Frame 1(SiF1)
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Register Name: RRA
Register Description: Receive Remote Alarm
Register Address: 5Ah
Bit # 7 6 5 4 3 2 1 0
Name RRAF1 RRAF3 RRAF5 RRAF7 RRAF9 RRAF11 RRAF13 RRAF15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Remote Alarm Bit of Frame 15(RRAF15)
Bit 1: Remote Alarm Bit of Frame 13(RRAF13)
Bit 2: Remote Alarm Bit of Frame 11(RRAF11)
Bit 3: Remote Alarm Bit of Frame 9(RRAF9)
Bit 4: Remote Alarm Bit of Frame 7(RRAF7)
Bit 5: Remote Alarm Bit of Frame 5(RRAF5)
Bit 6: Remote Alarm Bit of Frame 3(RRAF3)
Bit 7: Remote Alarm Bit of Frame 1(RRAF1)
Register Name: RSa4
Register Description: Receive Sa4 Bits
Register Address: 5Bh
Bit # 7 6 5 4 3 2 1 0
Name RSa4F1 RSa4F3 RSa4F5 RSa4F7 RSa4F9 RSa4F11 RSa4F13 RSa4F15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Sa4 Bit of Frame 15(RSa4F15)
Bit 1: Sa4 Bit of Frame 13(RSa4F13)
Bit 2: Sa4 Bit of Frame 11(RSa4F11)
Bit 3: Sa4 Bit of Frame 9(RSa4F9)
Bit 4: Sa4 Bit of Frame 7(RSa4F7)
Bit 5: Sa4 Bit of Frame 5(RSa4F5)
Bit 6: Sa4 Bit of Frame 3(RSa4F3)
Bit 7: Sa4 Bit of Frame 1(RSa4F1)
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Register Name: RSa5
Register Description: Receive Sa5 Bits
Register Address: 5Ch
Bit # 7 6 5 4 3 2 1 0
Name RSa5F1 RSa5F3 RSa5F5 RSa5F7 RSa5F9 RSa5F11 RSa5F13 RSa5F15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Sa5 Bit of Frame 15(RSa5F15)
Bit 1: Sa5 Bit of Frame 13(RSa5F13)
Bit 2: Sa5 Bit of Frame 11(RSa5F11)
Bit 3: Sa5 Bit of Frame 9(RSa5F9)
Bit 4: Sa5 Bit of Frame 7(RSa5F7)
Bit 5: Sa5 Bit of Frame 5(RSa5F5)
Bit 6: Sa5 Bit of Frame 3(RSa5F3)
Bit 7: Sa5 Bit of Frame 1(RSa5F1)
Register Name: RSa6
Register Description: Receive Sa6 Bits
Register Address: 5Dh
Bit # 7 6 5 4 3 2 1 0
Name RSa6F1 RSa6F3 RSa6F5 RSa6F7 RSa6F9 RSa6F11 RSa6F13 RSa6F15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Sa6 Bit of Frame 15(RSa6F15)
Bit 1: Sa6 Bit of Frame 13(RSa6F13)
Bit 2: Sa6 Bit of Frame 11(RSa6F11)
Bit 3: Sa6 Bit of Frame 9(RSa6F9)
Bit 4: Sa6 Bit of Frame 7(RSa6F7)
Bit 5: Sa6 Bit of Frame 5(RSa6F5)
Bit 6: Sa6 Bit of Frame 3(RSa6F3)
Bit 7: Sa6 Bit of Frame 1(RSa6F1)
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Register Name: RSa7
Register Description: Receive Sa7 Bits
Register Address: 5Eh
Bit # 7 6 5 4 3 2 1 0
Name RSa7F1 RSa7F3 RSa7F5 RSa7F7 RSa7F9 RSa7F11 RSa7F13 RSa7F15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Sa7 Bit of Frame 15(RSa7F15)
Bit 1: Sa7 Bit of Frame 13(RSa7F13)
Bit 2: Sa7 Bit of Frame 11(RSa7F11)
Bit 3: Sa7 Bit of Frame 9(RSa7F9)
Bit 4: Sa7 Bit of Frame 7(RSa7F7)
Bit 5: Sa7 Bit of Frame 5(RSa7F5)
Bit 6: Sa7 Bit of Frame 3(RSa7F3)
Bit 7: Sa7 Bit of Frame 1(RSa4F1)
Register Name: RSa8
Register Description: Receive Sa8 Bits
Register Address: 5Fh
Bit # 7 6 5 4 3 2 1 0
Name RSa8F1 RSa8F3 RSa8F5 RSa8F7 RSa8F9 RSa8F11 RSa8F13 RSa8F15
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Sa8 Bit of Frame 15(RSa8F15)
Bit 1: Sa8 Bit of Frame 13(RSa8F13)
Bit 2: Sa8 Bit of Frame 11(RSa8F11)
Bit 3: Sa8 Bit of Frame 9(RSa8F9)
Bit 4: Sa8 Bit of Frame 7(RSa8F7)
Bit 5: Sa8 Bit of Frame 5(RSa8F5)
Bit 6: Sa8 Bit of Frame 3(RSa8F3)
Bit 7: Sa8 Bit of Frame 1(RSa8F1)
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Register Name: TSiAF
Register Description: Transmit Si Bits of the Align Frame
Register Address: 42h
Bit # 7 6 5 4 3 2 1 0
Name TsiF0 TsiF2 TsiF4 TsiF6 TsiF8 TsiF10 TsiF12 TsiF14
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Si Bit of Frame 14(TsiF14)
Bit 1: Si Bit of Frame 12(TsiF12)
Bit 2: Si Bit of Frame 10(TsiF10)
Bit 3: Si Bit of Frame 8(TsiF8)
Bit 4: Si Bit of Frame 6(TsiF6)
Bit 5: Si Bit of Frame 4(TsiF4)
Bit 6: Si Bit of Frame 2(TsiF2)
Bit 7: Si Bit of Frame 0(TsiF0)
Register Name: TSiNAF
Register Description: Transmit Si Bits of the Non-Align Frame
Register Address: 43h
Bit # 7 6 5 4 3 2 1 0
Name TsiF1 TsiF3 TsiF5 TsiF7 TsiF9 TsiF11 TsiF13 TSiF15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Si Bit of Frame 15(TSiF15)
Bit 1: Si Bit of Frame 13(TsiF13)
Bit 2: Si Bit of Frame 11(TsiF11)
Bit 3: Si Bit of Frame 9(TsiF9)
Bit 4: Si Bit of Frame 7(TsiF7)
Bit 5: Si Bit of Frame 5(TsiF5)
Bit 6: Si Bit of Frame 3(TsiF3)
Bit 7: Si Bit of Frame 1(TsiF1)
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Register Name: TRA
Register Description: Transmit Remote Alarm
Register Address: 44h
Bit # 7 6 5 4 3 2 1 0
Name TRAF1 TRAF3 TRAF5 TRAF7 TRAF9 TRAF11 TRAF13 TRAF15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Remote Alarm Bit of Frame 15(TRAF15)
Bit 1: Remote Alarm Bit of Frame 13(TRAF13)
Bit 2: Remote Alarm Bit of Frame 11(TRAF11)
Bit 3: Remote Alarm Bit of Frame 9(TRAF9)
Bit 4: Remote Alarm Bit of Frame 7(TRAF7)
Bit 5: Remote Alarm Bit of Frame 5(TRAF5)
Bit 6: Remote Alarm Bit of Frame 3(TRAF3)
Bit 7: Remote Alarm Bit of Frame 1(TRAF1)
Register Name: TSa4
Register Description: Transmit Sa4 Bits
Register Address: 45h
Bit # 7 6 5 4 3 2 1 0
Name TSa4F1 TSa4F3 TSa4F5 TSa4F7 TSa4F9 TSa4F11 TSa4F13 TSa4F15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Sa4 Bit of Frame 15(TSa4F15)
Bit 1: Sa4 Bit of Frame 13(TSa4F13)
Bit 2: Sa4 Bit of Frame 11(TSa4F11)
Bit 3: Sa4 Bit of Frame 9(TSa4F9)
Bit 4: Sa4 Bit of Frame 7(TSa4F7)
Bit 5: Sa4 Bit of Frame 5(TSa4F5)
Bit 6: Sa4 Bit of Frame 3(TSa4F3)
Bit 7: Sa4 Bit of Frame 1(TSa4F1)
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Register Name: TSa5
Register Description: Transmit Sa5 Bits
Register Address: 46h
Bit # 7 6 5 4 3 2 1 0
Name TSa5F1 TSa5F3 TSa5F5 TSa5F7 TSa5F9 TSa5F11 TSa5F13 TSa5F15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Sa5 Bit of Frame 15(TSa5F15)
Bit 1: Sa5 Bit of Frame 13(TSa5F13)
Bit 2: Sa5 Bit of Frame 11(TSa5F11)
Bit 3: Sa5 Bit of Frame 9(TSa5F9)
Bit 4: Sa5 Bit of Frame 7(TSa5F7)
Bit 5: Sa5 Bit of Frame 5(TSa5F5)
Bit 6: Sa5 Bit of Frame 3(TSa5F3)
Bit 7: Sa5 Bit of Frame 1(TSa5F1)
Register Name: TSa6
Register Description: Transmit Sa6 Bits
Register Address: 47h
Bit # 7 6 5 4 3 2 1 0
Name TSa6F1 TSa6F3 TSa6F5 TSa6F7 TSa6F9 TSa6F11 TSa6F13 TSa6F15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Sa6 Bit of Frame 15(TSa6F15)
Bit 1: Sa6 Bit of Frame 13(TSa6F13)
Bit 2: Sa6 Bit of Frame 11(TSa6F11)
Bit 3: Sa6 Bit of Frame 9(TSa6F9)
Bit 4: Sa6 Bit of Frame 7(TSa6F7)
Bit 5: Sa6 Bit of Frame 5(TSa6F5)
Bit 6: Sa6 Bit of Frame 3(TSa6F3)
Bit 7: Sa6 Bit of Frame 1(TSa6F1)
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Register Name: TSa7
Register Description: Transmit Sa7 Bits
Register Address: 48h
Bit # 7 6 5 4 3 2 1 0
Name TSa7F1 TSa7F3 TSa7F5 TSa7F7 TSa7F9 TSa7F11 TSa7F13 TSa7F15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Sa7 Bit of Frame 15(TSa7F15)
Bit 1: Sa7 Bit of Frame 13(TSa7F13)
Bit 2: Sa7 Bit of Frame 11(TSa7F11)
Bit 3: Sa7 Bit of Frame 9(TSa7F9)
Bit 4: Sa7 Bit of Frame 7(TSa7F7)
Bit 5: Sa7 Bit of Frame 5(TSa7F5)
Bit 6: Sa7 Bit of Frame 3(TSa7F3)
Bit 7: Sa7 Bit of Frame 1(TSa4F1)
Register Name: TSa8
Register Description: Transmit Sa8 Bits
Register Address: 49h
Bit # 7 6 5 4 3 2 1 0
Name TSa8F1 TSa8F3 TSa8F5 TSa8F7 TSa8F9 TSa8F11 TSa8F13 TSa8F15
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Sa8 Bit of Frame 15(TSa8F15)
Bit 1: Sa8 Bit of Frame 13(TSa8F13)
Bit 2: Sa8 Bit of Frame 11(TSa8F11)
Bit 3: Sa8 Bit of Frame 9(TSa8F9)
Bit 4: Sa8 Bit of Frame 7(TSa8F7)
Bit 5: Sa8 Bit of Frame 5(TSa8F5)
Bit 6: Sa8 Bit of Frame 3(TSa8F3)
Bit 7: Sa8 Bit of Frame 1(TSa8F1)
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Register Name: TSACR
Register Description: Transmit Sa Bit Control Register
Register Address: 4Ah
Bit # 7 6 5 4 3 2 1 0
Name SiAF SiNAF RA Sa4 Sa5 Sa6 Sa7 Sa8
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Additional Bit 8 Insertion Control Bit (Sa8)
0 = do not insert data from the TSa8 register into the transmit data stream
1 = insert data from the TSa8 register into the transmit data stream
Bit 1: Additional Bit 7 Insertion Control Bit (Sa7)
0 = do not insert data from the TSa7 register into the transmit data stream
1 = insert data from the TSa7 register into the transmit data stream
Bit 2: Additional Bit 6 Insertion Control Bit (Sa6)
0 = do not insert data from the TSa6 register into the transmit data stream
1 = insert data from the TSa6 register into the transmit data stream
Bit 3: Additional Bit 5 Insertion Control Bit (Sa5)
0 = do not insert data from the TSa5 register into the transmit data stream
1 = insert data from the TSa5 register into the transmit data stream
Bit 4: Additional Bit 4 Insertion Control Bit (Sa4)
0 = do not insert data from the TSa4 register into the transmit data stream
1 = insert data from the TSa4 register into the transmit data stream
Bit 5: Remote Alarm Insertion Control Bit (RA)
0 = do not insert data from the TRA register into the transmit data stream
1 = insert data from the TRA register into the transmit data stream
Bit 6: International Bit in Non-Align Frame Insertion Control Bit (SiNAF)
0 = do not insert data from the TSiNAF register into the transmit data stream
1 = insert data from the TSiNAF register into the transmit data stream
Bit 7: International Bit in Align Frame Insertion Control Bit (SiAF)
0 = do not insert data from the TSiAF register into the transmit data stream
1 = insert data from the TSiAF register into the transmit data stream
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12.2 Alternate Sa/Si Bit Access Based on Double-Frame
On the receive side, the RAF and RNAF registers will always report the data as it received in the Sa and
Si bit locations. The RAF and RNAF registers are updated on align frame boundaries. The setting of the
receive align frame bit in status register 4 (SR4.0) will indicate that the contents of the RAF and RNAF
have been updated. The host can use the SR4.0 bit to know when to read the RAF and RNAF registers.
The host has 250µs to retrieve the data before it is lost.
On the transmit side, data is sampled from the TAF and TNAF registers with the setting of the transmit
align frame bit in status register 4 (SR4.3). The host can use the SR4.3 bit to know when to update the
TAF and TNAF registers. It has 250µs to update the data or else the old data will be retransmitted. If the
TAF an TNAF registers are only being used to source the align frame and non-align frame-sync
patterns, then the host need only write once to these registers. Data for the Si bit can come from the Si
bits of the RAF and TNAF registers, the TSiAF and TSiNAF registers, or passed through from the TSER
pin.
Register Name: RAF
Register Description: Receive Align Frame Register
Register Address: 56h
Bit # 7 6 5 4 3 2 1 0
Name Si FAS6 FAS5 FAS4 FAS3 FAS2 FAS1 FAS0
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Frame Alignment Signal Bit 0 (FAS0). In normal operation this bit will be = 1.
Bit 1: Frame Alignment Signal Bit 1 (FAS1). In normal operation this bit will be = 1.
Bit 2: Frame Alignment Signal Bit 2 (FAS2). In normal operation this bit will be = 0.
Bit 3: Frame Alignment Signal Bit 3 (FAS3). In normal operation this bit will be = 1.
Bit 4: Frame Alignment Signal Bit 4 (FAS4). In normal operation this bit will be = 1.
Bit 5: Frame Alignment Signal Bit 5 (FAS5). In normal operation this bit will be = 0.
Bit 6: Frame Alignment Signal Bit 6 (FAS6). In normal operation this bit will be = 0.
Bit 7: International Bit (Si)
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Register Name: RNAF
Register Description: Receive Non-Align Frame Register
Register Address: 57h
Bit # 7 6 5 4 3 2 1 0
Name Si 1 A Sa4 Sa5 Sa6 Sa7 Sa8
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bit 0: Additional Bit 8 (Sa8)
Bit 1: Additional Bit 7 (Sa7)
Bit 2: Additional Bit 6 (Sa6)
Bit 3: Additional Bit 5 (Sa5)
Bit 4: Additional Bit 4 (Sa4)
Bit 5: Remote Alarm (A)
Bit 6: Frame Nonalignment Signal Bit (1). In normal operation this bit will be = 1.
Bit 7: International Bit (Si)
Register Name: TAF
Register Description: Transmit Align Frame Register
Register Address: 40h
Bit # 7 6 5 4 3 2 1 0
Name Si 0 0 1 1 0 1 1
Default 0 0 0 1 1 0 1 1
HW
Mode 0 0 0 1 1 0 1 1
Bit 0: Frame Alignment Signal Bit (1)
Bit 1: Frame Alignment Signal Bit (1)
Bit 2: Frame Alignment Signal Bit (0)
Bit 3: Frame Alignment Signal Bit (1)
Bit 4: Frame Alignment Signal Bit (1)
Bit 5: Frame Alignment Signal Bit (0)
Bit 6: Frame Alignment Signal Bit (0)
Bit 7: International Bit (Si)
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Register Name: TNAF
Register Description: Transmit Non-Align Frame Register
Register Address: 41h
Bit # 7 6 5 4 3 2 1 0
Name Si 1 A Sa4 Sa5 Sa6 Sa7 Sa8
Default 0 1 0 0 0 0 0 0
Bit 0: Additional Bit 8 (Sa8)
Bit 1: Additional Bit 7 (Sa7)
Bit 2: Additional Bit 6 (Sa6)
Bit 3: Additional Bit 5 (Sa5)
Bit 4: Additional Bit 4 (Sa4)
Bit 5: Remote Alarm (used to transmit the alarm A)
Bit 6: Frame Nonalignment Signal Bit (1)
Bit 7: International Bit (Si)
DS26502
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13. LINE INTERFACE UNIT (LIU)
The LIU in the DS26502 contains three sections: the receiver, which handles clock and data recovery; the
transmitter, which generates waveshapes and drives the network line; and the jitter attenuator. These three
sections are controlled by the line interface control registers (LIC1–LIC4), which are described below.
The DS26502 can switch among T1, J1, E1, and 6312kHz without changing any external circuits. A
different transformer is used for 64KCC networks. For a list of recommended transformer part numbers,
contact technical support at www.maxim-ic.com/support. Figure 13-1 shows a network connection using
minimal components. In this configuration the DS26502, using a fixed 120Ω external termination, can
connect to T1, J1, E1, 64KCC, or 6312kHz. The receiver can adjust the 120Ω termination to 100Ω, 110Ω
or 75Ω. The transmitter can adjust its output impedance to provide high return loss characteristics for
75Ω, 100Ω, 110Ω, and 120Ω lines. Other components may be added to this configuration to meet safety
and network protection requirements. This is covered in the Recommended Circuits section (Section
13.8).
Figure 13-1. Basic Network Connection
TTIP
TRING
RTIP
RRING
DS26502
TRANSMIT
LINE
RECEIVE
LINE
10
μ
F
60 60
0.01
μ
F
BACKPLANE
CONNECTIONS
1:1
2:1
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13.1 LIU Operation
The LIU interfaces the T1, E1, 64KCC, and 6312kHz signals to the various types of network media
through coupling transformers. The LIU transmit and receive functions are independent. For example, the
receiver can be in T1 mode while the transmitter is in E1 mode. The 6312kHz transmission is an
exception to the other modes. For transmission, 6312kHz is only available as a 0 to 3.3V signal on the
TCLKO pin. It is not output to the TTIP and TRING pins for coupling to twisted pair. Because the G.703
specifications of the transmit pulse shape for Japanese 6312kHz are unclear, the user can externally filter
this signal to generate a sine wave type of signal. However, on the receive side, 6312kHz can be input
through the receive transformer to the RTIP and RRING pins.
13.2 LIU Receiver
The analog AMI/HDB3 E1 waveform, AMI/B8ZS T1 waveform, or AMI 64KCC waveform is
transformer-coupled into the RTIP and RRING pins of the DS26502. The user has the option to use
internal termination, software-selectable for 75/100/110/120Ω applications, or external termination. The
LIU recovers clock and data from the analog signal and passes it through the jitter attenuation mux.
(Note: The jitter attenuator is only available in T1 or E1 mode.) The DS26502 contains an active filter
that reconstructs the analog-received signal for the nonlinear losses that occur in long-haul T1 and E1
transmission. The receiver is configurable for various T1 and E1 monitor applications. The device has a
usable receive sensitivity of 0dB to –43dB for E1 and 0dB to –36dB for T1, which allows the device to
operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6000ft (T1) in length.
The DS26502’s LIU is designed to be fully software selectable for E1 and T1 without the need to change
any external resistors for the receive-side. The receiver will allow the user to configure the DS26502 for
75Ω, 100Ω, 110Ω, or 120Ω receive termination by setting the RT0(LIC4.0), RT1(LIC4.1), and
RT2(LIC4.2). When using the internal termination feature, the resistors labeled R in Figure 13-4 should
be 60Ω each. If external termination is used, RT0, RT1, and RT2 should be set to zero and the resistors
labeled R in Figure 13-4 will need to be 37.5Ω, 50Ω, 55Ω, or 60Ω each, depending on the required
termination.
There are two ranges of receive sensitivity for T1 and E1, which is selectable by the user. The EGL bit of
LIC1 (LIC1.4) selects the full or limited sensitivity.
Normally, the clock that is output at the RCLK pin is the recovered clock from the waveform presented at
the RTIP and RRING inputs. If the jitter attenuator is placed in the receive path (as is the case in most
applications), the jitter attenuator restores the RCLK to an approximate 50% duty cycle. If the jitter
attenuator is either placed in the transmit path or is disabled, the RCLK output can exhibit slightly shorter
high cycles of the clock. This is due to the highly over-sampled digital clock recovery circuitry. See the
Receive AC Timing Characteristics section for more details. When no signal is present at RTIP and
RRING, a receive loss of signal (RLOS) condition will occur and the signal at RCLK will be derived
from the scaled signal present on the MCLK pin JACLK.
13.2.1 Receive Level Indicator
The DS26502 will report the signal strength at RTIP and RRING in 2.5dB increments via RL3-RL0
located in the Information Register 1 (INFO1). This feature is helpful when trouble shooting line
performance problems.
DS26502 T1/E1/J1/64KCC BITS Element
79 of 125
13.2.2 Receive G.703 Section 13 Synchronization Signal
The DS26502 can receive a 2.048MHz square-wave synchronization clock as specified in Section 13 of
ITU G.703. To use the DS26502 in this mode, set the mode configuration bits in the Mode Configuration
Register (MCREG).
13.2.3 Monitor Mode
Monitor applications in both E1 and T1 require various flat gain settings for the receive-side circuitry.
The DS26502 can be programmed to support these applications via the monitor mode control bits MM1
and MM0 in the LIC3 register.
Figure 13-2. Typical Monitor Application
13.3 LIU Transmitter
The DS26502 uses a phase-lock loop along with a precision digital-to-analog converter (DAC) to create
the waveforms that are transmitted onto the E1 or T1 line. The waveforms created by the DS26502 meet
the latest ETSI, ITU, ANSI, and AT&T specifications. The waveform that is to be generated is set by the
transmit mode bits (TMODE[3:0]) in the MCREG register, as well as the L2/L1/L0 bits in register LIC1
if applicable.
ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs
require an accuracy of ±32ppm for T1 interfaces. The transmit clock can be sourced from the recovered
clock (RCLK), the pre-scaled MCLK, the TCLK pin or the TX PLL. See the TX PLL clock mux diagram
in Figure 3-3. Due to the nature of the design of the transmitter in the DS26502, very little jitter (less than
0.005UIP-P broadband from 10Hz to 100kHz) is added to the jitter present on the selected transmit clock
source. Also, the waveforms created are independent of the duty cycle of TCLK. The transmitter in the
DS26502 couples to the transmit twisted pair (or coaxial cable in some applications) via a 1:2 step-up
transformer. For the device to create the proper waveforms, the transformer used must meet the
specifications listed in Table 13-1. The DS26502 has the option of using software-selectable transmit
termination.
PRIMARY
T1/E1 TERMINATING
DEVICE
MONITOR
PORT JACK
T1/E1 LINE
X
F
M
R
DS26502
Rt
Rm Rm
SECONDARY T1/E1
TERMINATING
DEVICE
DS26502
80 of 125
The transmit line drive has two modes of operation: fixed gain or automatic gain. In the fixed gain mode,
the transmitter outputs a fixed current into the network load to achieve a nominal pulse amplitude. In the
automatic gain mode, the transmitter adjusts its output level to compensate for slight variances in the
network load. See the Transmit Line Build-Out Control (TLBC) register for details.
13.3.1 Transmit Short-Circuit Detector/Limiter
The DS26502 has an automatic short-circuit limiter that limits the source current to approximately 50mA
(rms) on the network side of the transformer in E1 modes of operations and 70mA (RMS) on the network
side of the transformer in T1 modes of operation. These values are approximate and are not guaranteed by
production testing. This feature can be disabled by setting the SCLD bit (LIC2.1) = 1. TCLE (SR1.2)
provides a real-time indication of when the current limiter is activated. If the current limiter is disabled,
TCLE will indicate that a short-circuit condition exist. Status Register SR1.2 provides a latched version
of the information, which can be used to activate an interrupt when enable via the IMR1 register. When
set low, the TPD bit (LIC1.0) will power-down the transmit line driver and three-state the TTIP and
TRING pins.
13.3.2 Transmit Open-Circuit Detector
The DS26502 can also detect when the TTIP or TRING outputs are open circuited. TOCD (SR1.1) will
provide a real-time indication of when an open circuit is detected. SR1 provides a latched version of the
information (SR1.1), which can be used to activate an interrupt when enable via the IMR1 register. The
functionality of these bits is not guaranteed by production testing.
13.3.3 Transmit BPV Error Insertion
When IBPV (LIC2.5) is transitioned from a zero to a one, the device waits for the next occurrence of
three consecutive ones to insert a BPV. IBPV must be cleared and set again for another BPV error
insertion.
13.3.4 Transmit G.703 Section 10 Synchronization Signal (E1 Mode)
The DS26502 can transmit the 2.048MHz square-wave synchronization clock. To transmit the 2.048MHz
clock, when in E1 mode, set the mode configuration bits in the Mode Configuration Register (MCREG).
13.4 MCLK Pre-Scaler
A 2.048MHz x 2N (where N = 0 to 3), 1.544MHz x 2N (where N = 0 to 3), or 12.8MHz (available in CPU
interface mode only) clock must be applied to MCLK. A pre-scaler (divide by 2, 4, or 8) and PLLs are
selected to product an internal 2.048MHz or 1.544MHz clock. ITU specification G.703 requires an accuracy
of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces.
A pre-scaler divides the 16.384MHz, 12.8MHz, 8.192MHz, or 4.096MHz clock down to 2.048MHz. An on-
board PLL for the jitter attenuator converts the 2.048MHz clock to a 1.544MHz rate for T1 applications.
Setting JACKS0 (LIC2.3) to logic 0 bypasses this PLL.
13.5 Jitter Attenuator
The jitter attenuator is only available in T1 and E1 modes. The DS26502’s jitter attenuator can be set to a
depth of either 32 bits or 128 bits via the JABDS bit (LIC1.2). The 128-bit mode is used in applications
where large excursions of wander are expected. The 32-bit mode is used in delay-sensitive applications.
The characteristics of the attenuation are shown in Figure 13-10 and Figure 13-11. The jitter attenuator
can be placed in either the receive path or the transmit path by appropriately setting or clearing the JAS
bit (LIC1.3). If the part is configured for hardware mode and the jitter attenuator is enabled, it will
DS26502 T1/E1/J1/64KCC BITS Element
81 of 125
automatically be placed in the receive path. The jitter attenuator can also be disabled (in effect, removed)
by setting the DJA bit (LIC1.1). Either the recovered clock from the clock/data recovery block or the
clock applied at the TCLK pin is adjusted to create a smooth jitter-free clock that is used to clock data out
of the jitter attenuator FIFO. It is acceptable to provide a gapped/bursty clock at the TCLK pin if the
jitter attenuator is placed on the transmit side. If the incoming jitter exceeds either 120 UIP-P (buffer
depth is 128 bits) or 28 UIP-P (buffer depth is 32 bits), then the DS26502 will divide the internal nominal
32.768MHz (E1) or 24.704MHz (T1) clock by either 15 or 17 instead of the normal 16 to keep the buffer
from overflowing. When the device divides by either 15 or 17, it also sets the Jitter Attenuator Limit Trip
(JALT) bit in Status Register 1 (SR1.4).
13.6 CMI (Code Mark Inversion) Option
The DS26502 provides a CMI interface for connection to optical transports. This interface is a unipolar
1T2B type of signal. Ones are encoded as either a logical one or zero level for the full duration of the
clock period. Zeros are encoded as a zero-to-one transition at the middle of the clock period.
Figure 13-3. CMI Coding
Transmit and receive CMI is enabled via LIC4.7. When this register bit is set, the TTIP pin will output
CMI-coded data at normal levels. This signal can be used to directly drive an optical interface. When
CMI is enabled, the user can also use HDB3/B8ZS coding. When this register bit is set, the RTIP pin will
become a unipolar CMI input. The CMI signal will be processed to extract and align the clock with data.
01 11001
CLOCK
DATA
CMI
DS26502
82 of 125
13.7 LIU Control Registers
Register Name: LIC1
Register Description: Line Interface Control 1
Register Address: 30h
Bit # 7 6 5 4 3 2 1 0
Name L2 L1 L0 EGL JAS JABDS DJA TPD
Default 0 0 0 0 0 0 0 0
HW
Mode
L2
PIN 13
L1
PIN 12
L0
PIN 11 0 0 0 0 1
Bit 0: Transmit Power-Down (TPD)
0 = powers down the transmitter and three-states the TTIP and TRING pins
1 = normal transmitter operation
Bit 1: Disable Jitter Attenuator (DJA). Note: The jitter attenuator is only available in T1 and E1 modes.
0 = jitter attenuator enabled
1 = jitter attenuator disabled
Bit 2/Jitter Attenuator Buffer Depth Select (JABDS). Note: The jitter attenuator is only available in T1 and E1 modes.
0 = 128 bits
1 = 32 bits (use for delay-sensitive applications)
Bit 3: Jitter Attenuator Select (JAS). Note: The jitter attenuator is only available in T1 and E1 modes.
0 = place the jitter attenuator on the receive side
1 = place the jitter attenuator on the transmit side
Bit 4: Receive Equalizer Gain Limit (EGL). This bit controls the sensitivity of the receive equalizer.
T1 Mode: 0 = -36dB (long haul)
1 = -15dB (limited long haul)
E1 Mode: 0 = -43dB (long haul)
1 = -12dB (short haul)
Bits 5 to 7: Line Build-Out Select (L0 to L2). When using the internal termination, the user needs only to select 000 for 75Ω
operation or 001 for 120Ω operation. This selects the proper voltage levels for 75Ω or 120Ω operation. Using TT0, TT1, and
TT2 of the LICR4 register, users can then select the proper internal source termination. Line build-outs 100 and 101 are for
backwards compatibility with older products only.
E1 Mode
L2 L1 L0 APPLICATION N (NOTE 1) RETURN
LOSS Rt (NOTE 1)
0 0 0 75Ω normal 1:2 N.M. 0
0 0 1 120Ω normal 1:2 N.M. 0
1 0 0 75Ω with high return loss (Note 2) 1:2 21dB 6.2Ω
1 0 1 120Ω with high return loss (Note 2) 1:2 21dB 11.6Ω
Note 1: Transformer turns ratio.
Note 2: TT0, TT1, and TT2 of LIC4 register must be set to zero in this configuration.
N.M. = not meaningful
DS26502 T1/E1/J1/64KCC BITS Element
83 of 125
T1 Mode
L2 L1 L0 APPLICATION N (NOTE 1) RETURN
LOSS Rt (NOTE 1)
0 0 0 DSX-1 (0 to 133 feet)/0dB CSU 1:2 N.M. 0
0 0 1 DSX-1 (133 to 266 feet) 1:2 N.M. 0
0 1 0 DSX-1 (266 to 399 feet) 1:2 N.M. 0
0 1 1 DSX-1 (399 to 533 feet) 1:2 N.M. 0
1 0 0 DSX-1 (533 to 655 feet) 1:2 N.M. 0
1 0 1 Reserved — — —
1 1 0 Reserved — — —
1 1 1 Reserved — — —
Note 1: Transformer turns ratio.
N.M. = not meaningful
Register Name: TLBC
Register Description: Transmit Line Build-Out Control
Register Address: 34h
Bit # 7 6 5 4 3 2 1 0
Name — AGCE GC5 GC4 GC3 GC2 GC1 GC0
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bits 0 to 5: Gain Control Bits 0–5 (GC0–GC5). The GC0 through GC5 bits control the gain setting for the non-automatic
gain mode. Use the tables below for setting the recommended values. The LB (line build-out) column refers to the value in the
L0–L2 bits in LIC1 (Line Interface Control 1) register.
NETWORK MODE LB GC5 GC4 GC3 GC2 GC1 GC0
0 1 0 0 1 1 0
1 0 1 1 0 1 1
2 0 1 1 0 1 0
3 1 0 0 0 0 0
4 1 0 0 1 1 1
5 1 0 0 1 1 1
6 0 1 0 0 1 1
T1, Impedance Match Off
7 1 1 1 1 1 1
0 0 1 1 1 1 0
1 0 1 0 1 0 1
2 0 1 0 1 0 1
3 0 1 1 0 1 0
4 1 0 0 0 1 0
5 1 0 0 0 0 0
6 0 0 1 1 0 0
T1, Impedance Match On
7 1 1 1 1 1 1
0 1 0 0 0 0 1
1 1 0 0 0 0 1
4 1 0 1 0 1 0
E1, Impedance Match Off
5 1 0 1 0 0 0
0 0 1 1 0 1 0
E1, Impedance Match On 1 0 1 1 0 1 0
Bit 6: Automatic Gain Control Enable (AGCE)
0 = use Transmit AGC, TLBC bits 0–5 are “don’t care”
1 = do not use Transmit AGC, TLBC bits 0–5 set nominal level
Bit 7: Unused, must be set = 0 for proper operation.
DS26502 T1/E1/J1/64KCC BITS Element
84 of 125
Register Name: LIC2
Register Description: Line Interface Control 2
Register Address: 31h
Bit # 7 6 5 4 3 2 1 0
Name JACKS1 LIRST IBPV TAIS JACKS0 RCCFE SCLD CLDS
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0
TAIS
PIN 10
JACKS
PIN 46 0 0 0
Bit 0: Custom Line Driver Select (CLDS). Setting this bit to a one will redefine the operation of the transmit line driver.
When this bit is set to a one and LIC1.5 = LIC1.6 = LIC1.7 = 0, then the device will generate a square wave at the TTIP and
TRING outputs instead of a normal waveform. When this bit is set to a one and LIC1.5 = LIC1.6 = LIC1.7 ≠ 0, then the device
will force TTIP and TRING outputs to become open-drain drivers instead of their normal push-pull operation. This bit should
be set to zero for normal operation of the device. Note: This bit should be set = 0 in 64KCC and 6312kHz transmit modes.
Bit 1: Short Circuit Limit Disable (in E1 mode) (SCLD). Controls the 50mA (rms) current limiter. Note: Not applicable in
6312kHz mode.
0 = enable 50mA current limiter
1 = disable 50mA current limiter
Bit 2: Receive Composite Clock Filter Enable (RCCFE). (64KCC mode only) Setting this bit will enable the PLL filter on
the received 64kHz composite clock. Note: the 8kHz and 400Hz output are not filtered.
0 = Receive Composite Clock Filter Disabled
1 = Receive Composite Clock Filter Enabled
Bit 3: Jitter Attenuator Clock Select 0 (JACKS0). This bit, along with JACKS1 (LIC2.7), MPS0 (LIC4.6), and MPS1
(LIC4.7), controls the source for JA CLOCK from the MCLK pin. Note: This bit must be configured even if the jitter
attenuator is disabled. The clock and data recovery engine also uses the JA CLOCK. Setting this bit enables the 2.048MHz to
1.544MHz conversion PLL for T1 applications. See the table in the LIC4 register description for more details on setting up the
JA CLOCK source.
0 = 2.048MHz to 1.544MHz PLL bypassed
1 = 2.048MHz to 1.544MHz PLL enabled
Bit 4: Transmit Alarm Indication Signal (TAIS)
0 = transmit an unframed all-ones code
1 = transmit data normally
Bit 5: Insert BPV (IBPV). A zero-to-one transition on this bit will cause a single BPV to be inserted into the transmit data
stream. Once this bit has been toggled from a zero to a one, the device waits for the next occurrence of three consecutive ones
to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted. Note: This function not
supported in 64KCC and 6312kHz modes.
Bit 6: Line Interface Reset (LIRST). Setting this bit from a zero to a one will initiate an internal reset that resets the clock
recovery state machine and recenters the jitter attenuator. Normally this bit is only toggled on power-up. Must be cleared and
set again for a subsequent reset.
Bit 7: Jitter Attenuator Clock Select 1 (JACKS1). This bit, along with JACKS0 (LIC2.3), MPS0 (LIC4.6), and MPS1
(LIC4.7), controls the source for JA CLOCK from the MCLK pin. Note: This bit must be configured even if the jitter
attenuator is disabled. The clock and data recovery engine also uses the JA CLOCK. Setting this bit enables the 12.8MHz to
2.048MHz conversion PLL. See the table in the LIC4 register description for more details on setting up the JA CLOCK source.
0 = 12.8MHz to 2.048MHz PLL bypassed
1 = 12.8MHz to 2.048MHz PLL enabled
DS26502 T1/E1/J1/64KCC BITS Element
85 of 125
Register Name: LIC3
Register Description: Line Interface Control 3
Register Address: 32h
Bit # 7 6 5 4 3 2 1 0
Name CMIE CMII — MM1 MM0 — — TAOZ
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0 0 0 0
Bit 0: Transmit Alternate Ones and Zeros (TAOZ). Transmit a …101010… pattern at TTIP and TRING.
0 = disabled
1 = enabled
Bits 1, 2, and 5: Unused, must be set = 0 for proper operation.
Bits 3 and 4: Monitor Mode (MM0 to MM1)
MM1 MM0 INTERNAL LINEAR GAIN BOOST (dB)
0 0 Normal operation (no boost)
0 1 20
1 0 26
1 1 32
Bit 6: CMI Invert (CMII)
0 = CMI normal at TTIP and RTIP
1 = invert CMI signal at TTIP and RTIP
Bit 7: CMI Enable (CMIE)
0 = disable CMI mode
1 = enable CMI mode
DS26502 T1/E1/J1/64KCC BITS Element
86 of 125
Register Name: LIC4
Register Description: Line Interface Control 4
Register Address: 33h
Bit # 7 6 5 4 3 2 1 0
Name MPS1 MPS0 TT2 TT1 TT0 RT2 RT1 RT0
Default 0 0 0 0 0 0 0 0
HW
Mode
MPS1
PIN 16
MPS0
PIN 15 — — — — — —
Bits 0 to 2: Receive Termination Select (RT0 to RT2)
RT2 RT1 RT0 INTERNAL RECEIVE
TERMINATION CONFIGURATION
0 0 0 Internal Receive-Side Termination Disabled
0 0 1 Internal Receive-Side 75Ω Enabled
0 1 0 Internal Receive-Side 100Ω Enabled
0 1 1 Internal Receive-Side 120Ω Enabled
1 0 0 Internal Receive-Side 110Ω Enabled
1 0 1 Internal Receive-Side Termination Disabled
1 1 0 Internal Receive-Side Termination Disabled
1 1 1 Internal Receive-Side Termination Disabled
Bits 3 to 5:Transmit Termination Select (TT0 to TT2)
TT2 TT1 TT0 INTERNAL TRANSMIT
TERMINATION CONFIGURATION
0 0 0 Internal Transmit-Side Termination Disabled
0 0 1 Internal Transmit-Side 75Ω Enabled
0 1 0 Internal Transmit-Side 100Ω Enabled
0 1 1 Internal Transmit-Side 120Ω Enabled
1 0 0 Internal Transmit-Side 110Ω Enabled
1 0 1 Internal Transmit-Side Termination Disabled
1 1 0 Internal Transmit-Side Termination Disabled
1 1 1 Internal Transmit-Side Termination Disabled
Bits 6 and 7: MCLK Pre-Scaler (MPS0 to MPS1) (T1 Mode)
MCLK (MHz) MPS1 MPS0 JACKS (LIC2.3)
1.544 0 0 0
3.088 0 1 0
6.176 1 0 0
12.352 1 1 0
2.048 0 0 1
4.096 0 1 1
8.192 1 0 1
16.384 1 1 1
Bits 6 and 7: MCLK Pre-Scaler (MPS0 to MPS1) (E1 Mode)
MCLK (MHz) MPS1 MPS0 JACKS0 (LIC2.3) JACKS1 (LIC2.7)
2.048 0 0 0 0
4.096 0 1 0 0
8.192 1 0 0 0
12.8 0 0 0 1
16.384 1 1 0 0
DS26502 T1/E1/J1/64KCC BITS Element
87 of 125
Register Name: INFO1
Register Description: Information Register 1
Register Address: 11h
Bit # 7 6 5 4 3 2 1 0
Name — — — — RL3 RL2 RL1 RL0
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bits 0 to 3: Receive Level Bits (RL0 to RL3). Real-time bits.
RL3 RL2 RL1 RL0 RECEIVE LEVEL (dB)
0 0 0 0 Greater than -2.5
0 0 0 1 -2.5 to -5.0
0 0 1 0 -5.0 to -7.5
0 0 1 1 -7.5 to -10.0
0 1 0 0 -10.0 to -12.5
0 1 0 1 -12.5 to -15.0
0 1 1 0 -15.0 to -17.5
0 1 1 1 -17.5 to -20.0
1 0 0 0 -20.0 to -22.5
1 0 0 1 -22.5 to -25.0
1 0 1 0 -25.0 to -27.5
1 0 1 1 -27.5 to -30.0
1 1 0 0 -30.0 to –32.5
1 1 0 1 -32.5 to -35.0
1 1 1 0 -35.0 to -37.5
1 1 1 1 Less than -37.5
Bits 4 to 7: Unused
DS26502 T1/E1/J1/64KCC BITS Element
88 of 125
Register Name: SR1
Register Description: Status Register 1
Register Address: 14h
Bit # 7 6 5 4 3 2 1 0
Name — — — JALT — TCLE TOCD —
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bits 0, 3, 5 to 7: Unused, must be set = 0 for proper operation.
Bit 1: Transmit Open Circuit Detect Condition (TOCD). Set when the device detects that the TTIP and TRING outputs are
open-circuited. Note: This function not supported in transmit 6312kHz mode and is not guaranteed by production testing.
Bit 2: Transmit Current Limit Exceeded Condition (TCLE). Set when the current limiter is activated whether the current
limiter is enabled or not. This is set at approximately 50mA (RMS) on the network side of the transformer in E1 operating
modes and 70mA (RMS) on the network side of the transformer in T1 operating modes. These values are approximate and are
not guaranteed by production testing. Note: This function not supported in transmit CMI, 64kHz or 6312kHz mode.
Bit 4: Jitter Attenuator Limit Trip Event (JALT). Set when the jitter attenuator FIFO reaches to within 4 bits of its useful
limit. Will be cleared when read. Useful for debugging jitter-attenuation operation. Note: The jitter attenuator is only available
in T1 and E1 modes.
DS26502 T1/E1/J1/64KCC BITS Element
89 of 125
Register Name: IMR1
Register Description: Interrupt Mask Register 1
Register Address: 15h
Bit # 7 6 5 4 3 2 1 0
Name — — — JALT — TCLE TOCD —
Default 0 0 0 0 0 0 0 0
HW
Mode X X X X X X X X
Bits 0, 3, 5 to 7: Unused, must be set = 0 for proper operation.
Bit 1: Transmit Open Circuit Detect Condition (TOCD)
0 = interrupt masked
1 = interrupt enabled–generates interrupts on rising and falling edges
Bit 2: Transmit Current Limit Exceeded Condition (TCLE)
0 = interrupt masked
1 = interrupt enabled–generates interrupts on rising and falling edges
Bit 4: Jitter Attenuator Limit Trip Event (JALT)
0 = interrupt masked
1 = interrupt enabled
DS26502
90 of 125
13.8 Recommended Circuits
Figure 13-4. Software-Selected Termination, Metallic Protection
DS26502
DVDD
DVSS
TVSS
TVDD
RVSS
RVDD
0.01 uF 0.1 uF
68 uF
0.1 uF
0.1 uF
3.3 V
3.3 V
TTIP
TRING
RTIP
RRING
S1
S2
S3
S4
T1
T2
T3
T4
2:1
1:1
F1
F2
TX
TIP
TX
RING
RX
TIP
RX
RING
60 60
0.1 uF
10uF
Table 13-1. Component List (Software-Selected Termination, Metallic
Protection)
NAME DESCRIPTION
F1 and F2 1.25A slow blow fuse
S1 and S2 25V (max) transient suppressor
S3 andS4 77V (max) transient suppressor
Transformer 1:1CT and 1:136CT (5.0V, SMT) (Note 1)
T1 and T2 Transformer 1:1CT and 1:2CT (3.3V, SMT) (Note 1)
T3 and T4 Dual common-mode choke (SMT)
Note 1: T3 and T4 are optional. For more information, contact the Telecom Support Group at
www.maxim-ic.com/support.
Note 2: The layout from the transformers to the network interface is critical. Traces should be at least 25
mils wide and separated from other circuit lines by at least 150 mils. The area under this portion
of the circuit should not contain power planes.
Note 3: Some T1 (never in E1) applications source or sink power from the network-side center taps of
the Rx/Tx transformers.
Note 4: A list of transformer part numbers and manufacturers is available by contacting
www.maxim-ic.com/support.
DS26502
91 of 125
Figure 13-5. Software-Selected Termination, Longitudinal Protection
DS26502
DVDD
DVSS
TVSS
TVDD
RVSS
RVDD
0.01 uF 0.1 uF
68 uF
0.1 uF
0.1 uF
3.3 V
3.3 V
TTIP
TRING
RTIP
RRING
S1
S2
S3
S4
S5
S6
S7
S8
T1
T2
T3
T4
2:1
1:1
F1
F2
F3
F4
TX
TIP
TX
RING
RX
TIP
RX
RING
60 60
0.1 uF
10uF
Table 13-2. Component List (Software-Selected Termination, Longitudinal
Protection)
NAME DESCRIPTION
F1 to F4 1.25A slow blow fuse
S1 and S2 25V (max) transient suppressor (Note 1)
S3, S4, S5, S6 180V (max) transient suppressor (Note 1)
S7 and S8 40V (max) transient suppressor
Transformer 1:1CT and 1:136CT (5.0V, SMT) (Note 2)
T1 and T2 Transformer 1:1CT and 1:2CT (3.3V, SMT) (Note 2)
T3 and T4 Dual common-mode choke (SMT)
Note 1: T3 and T4 are optional. For more information, contact the Telecom Support Group at
www.maxim-ic.com/support.
Note 2: A list of alternate transformer part numbers and manufacturers is available at
www.maxim-ic.com/support.
Note 3: The layout from the transformers to the network interface is critical. Traces should be at least 25
mils wide and separated from other circuit lines by at least 150 mils. The area under this portion
of the circuit should not contain power planes.
Note 4: Some T1 (never in E1) applications source or sink power from the network-side center taps of
the Rx/Tx transformers.
Note 5: The ground trace connected to the S2/S3 pair and the S4/S5 pair should be at least 50 mils wide
to conduct the extra current from a longitudinal power-cross event.
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 13-6. E1 Transmit Pulse Template
Figure 13-7. T1 Transmit Pulse Template
0
-0.1
-0.2
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
0
TIME (ns)
SCALED AMPLITUDE
50 100 150 200 250-50-100-150-200-250
269ns
194ns
219ns
(in 75 ohm systems, 1.0 on the scale = 2.37Vpeak
in 120 ohm systems, 1.0 on the scale = 3.00Vpeak)
G.703
Template
0
-0.1
-0.2
-0.3
-0.4
-0.5
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
-500 -300 -100 0 300 500 700
-400 -200 200 400 600100
TIME (ns)
NORMALIZED AMPLITUDE
T1.102/87, T1.403,
CB 119 (Oct. 79), &
I.431 Template
-0.77
-0.39
-0.27
-0.27
-0.12
0.00
0.27
0.35
0.93
1.16
-500
-255
-175
-175
-75
0
175
225
600
750
0.05
0.05
0.80
1.15
1.15
1.05
1.05
-0.07
0.05
0.05
-0.77
-0.23
-0.23
-0.15
0.00
0.15
0.23
0.23
0.46
0.66
0.93
1.16
-500
-150
-150
-100
0
100
150
150
300
430
600
750
-0.05
-0.05
0.50
0.95
0.95
0.90
0.50
-0.45
-0.45
-0.20
-0.05
-0.05
UI Time Amp.
MAXIMUM CURVE
UI Time Amp.
MINIMUM CURVE
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 13-8. Jitter Tolerance (T1 Mode)
Figure 13-9. Jitter Tolerance (E1 Mode)
UNIT INTERVALS (UIpp)
FREQUENCY (Hz)
1K
100
10
1
0.1
10 100 1K 10K 100K
DS26502
Tolerance
1
TR 62411 (Dec. 90)
ITU-T G.823
FREQUENCY (Hz)
UNIT INTERVALS (UIpp)
1k
100
10
1
0.1
10 100 1k 10k 100k
DS26502
Tolerance
1
Minimum Tolerance
Level as per
ITU G.823
40
1.5
0.2
20 2.4k 18k
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 13-10. Jitter Attenuation (T1 Mode)
Figure 13-11. Jitter Attenuation (E1 Mode)
FREQUENCY (Hz)
0dB
-20dB
-40dB
-60dB
1 10 100 1K 10K
JITTER ATTENUATION (dB)
100K
TR 62411 (Dec. 90)
Prohibited Area
Curve B
Curve A
DS26502
T1 MODE
FREQUENCY (Hz)
0dB
-20dB
-40dB
-60dB
1 10 100 1K 10K 100K
ITU G.7XX
Prohibited Area
TBR12
Prohibited
Area
DS26502
E1 MODE
JITTER ATTENUATION (dB)
DS26502 T1/E1/J1/64KCC BITS Element
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14. LOOPBACK CONFIGURATION
Register Name: LBCR
Register Description: Loopback Control Register
Register Address: 20h
Bit # 7 6 5 4 3 2 1 0
Name — — — — LLB RLB — —
Default 0 0 0 0 0 0 0 0
HW
Mode 0 0 0 0 0
RLB
PIN 60 0 0
Bits 0, 1, 4 to 7: Unused, must be set = 0 for proper operation.
Bit 2: Remote Loopback (RLB). In this loopback, data received at RTIP and RRING will be looped back to the transmit LIU.
Received data will continue to pass through the receive side framer of the DS26502 as it would normally and the data from the
transmit side formatter will be ignored.
0 = loopback disabled
1 = loopback enabled
Bit 3: Local Loopback (LLB). In this loopback, data will continue to be transmitted as normal through the transmit side of the
DS26502. Data being received at RTIP and RRING will be replaced with the data being transmitted. Data in this loopback will
pass through the jitter attenuator if enabled.
0 = loopback disabled
1 = loopback enabled
DS26502 T1/E1/J1/64KCC BITS Element
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15. 64kHz SYNCHRONIZATION INTERFACE
The 64kHz synchronization interface conforms to G.703 requirements for Centralized Timing (option A),
Contradirectional Timing, and 64kHz Appendix II. It consists of a composite clock, where a 64kHz clock
signal is generated or decoded, along with embedded frequencies of 8kHz and 400Hz. Those signals
consist of AMI code with an 8kHz bipolar violation removed at every 400Hz. There are two separate
modes referred to in the specification, one with both the 64kHz clock and the 8kHz clock, and the second
with the 64kHz clock, the 8kHz clock, and the 400Hz clock.
Figure 15-1. 64kHz Composite Clock Mode Signal Format
15.1 Receive 64kHz Synchronization Interface Operation
In the receive path, the three clock frequencies are decoded from the AMI waveform with bipolar
violations that is received at the LIU interface. The 8kHz frequency and the 400Hz frequency are decoded
from the presence or absence of bipolar violations as described in G.703.
Table 15-1. Specification of 64kHz Clock Signal at Input Port
Frequency a) 64kHz + 8kHz or
b) 64kHz + 8kHz + 400Hz
Signal format a) AMI with 8kHz bipolar violation,
b) AMI with 8kHz bipolar violation removed at every 400Hz
Alarm condition Alarm should not be occurred against the amplitude ranged
0.63-1.1 V0-P
Violation
No
Violation
Violation
Violation Violation
No
Violation
125 us 125 us 125 us 125 us
8 kHz
400 Hz
DS26502 T1/E1/J1/64KCC BITS Element
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15.2 Transmit 64kHz Synchronization Interface Operation
In the transmit path, the framer will generate the appropriate AMI waveform with the correct bipolar
violations as described by G.703. If an 8kHz signal is present on the TS_8K_4 pin, the bipolar violations
will be generated synchronously with this signal. If it is absent, the part will arbitrarily generate the
bipolar violation at an 8kHz frequency.
Table 15-2. Specification of 64kHz Clock
Signal at Output Port
Frequency a) 64kHz + 8kHz or
b) 64kHz + 8kHz + 400Hz
Load impedance 110Ω resistive
Transmission media Symmetric pair cable
Pulse width (FWHM) ≤ 7.8 ± 0.78µs
Amplitude ≤1 V0-P ± 0.1 V
DS26502
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16. 6312kHz SYNCHRONIZATION INTERFACE
The DS26502 has a 6312kHz Synchronization Interface mode of operation that conforms with Appendix
II.2 of G.703, with the exception that the DS26502 transmits a square wave as opposed to the sine wave
that is defined in the G.703 specification.
16.1 Receive 6312kHz Synchronization Interface Operation
On the receive interface, a 6312kHz sine wave is accepted conforming to the input port requirements of
G.703 Appendix II. Alternatively, a 6312kHz square wave will also be accepted. A 6312kHz square wave
is output on RCLK in the receive direction. RS_8K and 400Hz are not driven in this mode and will be
three-stated.
Table 16-1. Specification of 6312kHz Clock
Signal at Input Port
Frequency 6312kHz
Signal format Sinusoidal wave
Alarm condition Alarm should not be occurred against
the amplitude ranged
-16dBm to +3dBm
16.2 Transmit 6312kHz Synchronization Interface Operation
On the transmit interface, a nominally 50% duty cycle, 6312kHz square wave at standard logic levels is
available from the PLL_OUT pin. In normal operation, the TCLKO pin will output the same signal.
However, if remote loopback is enabled then TCLKO will be replaced with the recovered receive clock.
See Figure 3-1. The G.703 requirements for the 6312kHz transmitted signal are shown in Table 16-2. The
user must provide an external circuit to convert the TCLKO or PLL_OUT signal to the level and
impedance required by G.703. The RSER and TS_8K-4 pins are ignored in this mode. TTIP and TRING
will be three-stated in this mode.
Table 16-2. Specification of 6312kHz Clock
Signal at Output Port
Frequency 6312kHz
Load impedance 75Ω resistive
Transmission media Coaxial pair cable
Amplitude 0dBm ± 3dBm
DS26502 T1/E1/J1/64KCC BITS Element
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17. JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT
The DS26502 supports the standard IEEE 1149.1 instruction codes SAMPLE/PRELOAD, BYPASS, and
EXTEST. Optional public instructions included are HIGHZ, CLAMP, and IDCODE. The DS26502
contains the following as required by IEEE 1149.1 Standard Test Access Port and Boundary Scan
Architecture:
Test Access Port (TAP)
TAP Controller
Instruction Register
Bypass Register
Boundary Scan Register
Device Identification Register
Details on Boundary Scan Architecture and the Test Access Port can be found in IEEE 1149.1-1990,
IEEE 1149.1a-1993, and IEEE 1149.1b-1994.
The Test Access Port has the necessary interface pins: JTRST, JTCLK, JTMS, JTDI, and JTDO. See the
pin descriptions for details.
Figure 17-1. JTAG Functional Block Diagram
JTDI JTMS JTCLK
J
TRST JTDO
TEST ACCESS PORT
CONTROLLER
VDD VDD VDD
BOUNDRY SCAN
REGISTER
BYPASS
REGISTER
INSTRUCTION
REGISTER
IDENTIFICATION
REGISTER
MUX
SELECT
OUTPUT ENABLE
10kΩ 10kΩ 10k
Ω
DS26502 T1/E1/J1/64KCC BITS Element
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TAP Controller State Machine
The TAP controller is a finite state machine that responds to the logic level at JTMS on the rising edge of
JTCLK. See Figure 17-2.
Test-Logic-Reset
Upon power-up, the TAP controller will be in the test-logic-reset state. The instruction register will
contain the IDCODE instruction. All system logic of the device will operate normally.
Run-Test-Idle
The run-test-idle is used between scan operations or during specific tests. The instruction register and test
registers will remain idle.
Select-DR-Scan
All test registers retain their previous state. With JTMS LOW, a rising edge of JTCLK moves the
controller into the capture-DR state and will initiate a scan sequence. JTMS HIGH during a rising edge
on JTCLK moves the controller to the select-IR-scan state.
Capture-DR
Data can be parallel-loaded into the test-data registers selected by the current instruction. If the
instruction does not call for a parallel load or the selected register does not allow parallel loads, the test
register will remain at its current value. On the rising edge of JTCLK, the controller will go to the shift-
DR state if JTMS is LOW or it will go to the exit1-DR state if JTMS is HIGH.
Shift-DR
The test-data register selected by the current instruction will be connected between JTDI and JTDO and
will shift data one stage toward its serial output on each rising edge of JTCLK. If a test register selected
by the current instruction is not placed in the serial path, it will maintain its previous state.
Exit1-DR
While in this state, a rising edge on JTCLK will put the controller in the update-DR state, which
terminates the scanning process, if JTMS is HIGH. A rising edge on JTCLK with JTMS LOW will put
the controller in the pause-DR state.
Pause-DR
Shifting of the test registers is halted while in this state. All test registers selected by the current
instruction will retain their previous state. The controller will remain in this state while JTMS is LOW. A
rising edge on JTCLK with JTMS HIGH will put the controller in the exit2-DR state.
Exit2-DR
A rising edge on JTCLK with JTMS HIGH while in this state will put the controller in the update-DR
state and terminate the scanning process. A rising edge on JTCLK with JTMS LOW will enter the shift-
DR state.
Update-DR
A falling edge on JTCLK while in the update-DR state will latch the data from the shift register path of
the test registers into the data output latches. This prevents changes at the parallel output due to changes
in the shift register.
DS26502 T1/E1/J1/64KCC BITS Element
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Select-IR-Scan
All test registers retain their previous state. The instruction register will remain unchanged during this
state. With JTMS LOW, a rising edge on JTCLK moves the controller into the capture-IR state and will
initiate a scan sequence for the instruction register. JTMS HIGH during a rising edge on JTCLK puts the
controller back into the test-logic-reset state.
Capture-IR
The capture-IR state is used to load the shift register in the instruction register with a fixed value. This
value is loaded on the rising edge of JTCLK. If JTMS is HIGH on the rising edge of JTCLK, the
controller will enter the exit1-IR state. If JTMS is LOW on the rising edge of JTCLK, the controller will
enter the shift-IR state.
Shift-IR
In this state, the shift register in the instruction register is connected between JTDI and JTDO and shifts
data one stage for every rising edge of JTCLK toward the serial output. The parallel register as well as all
test registers remain at their previous states. A rising edge on JTCLK with JTMS HIGH will move the
controller to the exit1-IR state. A rising edge on JTCLK with JTMS LOW will keep the controller in the
shift-IR state while moving data one stage thorough the instruction shift register.
Exit1-IR
A rising edge on JTCLK with JTMS LOW will put the controller in the pause-IR state. If JTMS is HIGH
on the rising edge of JTCLK, the controller will enter the update-IR state and terminate the scanning
process.
Pause-IR
Shifting of the instruction shift register is halted temporarily. With JTMS HIGH, a rising edge on JTCLK
will put the controller in the exit2-IR state. The controller will remain in the pause-IR state if JTMS is
LOW during a rising edge on JTCLK.
Exit2-IR
A rising edge on JTCLK with JTMS LOW will put the controller in the update-IR state. The controller
will loop back to shift-IR if JTMS is HIGH during a rising edge of JTCLK in this state.
Update-IR
The instruction code shifted into the instruction shift register is latched into the parallel output on the
falling edge of JTCLK as the controller enters this state. Once latched, this instruction becomes the
current instruction. A rising edge on JTCLK with JTMS LOW, will put the controller in the run-test-idle
state. With JTMS HIGH, the controller will enter the select-DR-scan state.
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 17-2. TAP Controller State Diagram
1
0
0
1
11
1
1
1
11
11
11
00
00
0
1
00
00
11
00
00
Select
DR-Scan
Capture DR
Shift DR
Exit DR
Pause DR
Exit2 DR
Update DR
Select
IR-Scan
Capture IR
Shift IR
Exit IR
Pause IR
Exit2 IR
Update IR
Test Logic
Reset
Run Test/
Idle
0
DS26502 T1/E1/J1/64KCC BITS Element
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17.1 Instruction Register
The instruction register contains a shift register as well as a latched parallel output and is 3 bits in length.
When the TAP controller enters the shift-IR state, the instruction shift register will be connected between
JTDI and JTDO. While in the shift-IR state, a rising edge on JTCLK with JTMS LOW will shift the data
one stage toward the serial output at JTDO. A rising edge on JTCLK in the exit1-IR state or the exit2-IR
state with JTMS HIGH will move the controller to the update-IR state. The falling edge of that same
JTCLK will latch the data in the instruction shift register to the instruction parallel output.
Table 17-1. Instruction Codes for IEEE 1149.1 Architecture
INSTRUCTION SELECTED REGISTER INSTRUCTION CODES
SAMPLE/PRELOAD Boundary Scan 010
BYPASS Bypass 111
EXTEST Boundary Scan 000
CLAMP Bypass 011
HIGHZ Bypass 100
IDCODE Device Identification 001
SAMPLE/PRELOAD
This is a mandatory instruction for the IEEE 1149.1 specification that supports two functions. The digital
I/Os of the device can be sampled at the boundary scan register without interfering with the normal
operation of the device by using the capture-DR state. SAMPLE/PRELOAD also allows the device to
shift data into the boundary scan register via JTDI using the shift-DR state.
BYPASS
When the BYPASS instruction is latched into the parallel instruction register, JTDI connects to JTDO
through the one-bit bypass test register. This allows data to pass from JTDI to JTDO not affecting the
device’s normal operation.
EXTEST
This allows testing of all interconnections to the device. When the EXTEST instruction is latched in the
instruction register, the following actions occur. Once enabled via the Update-IR state, the parallel
outputs of all digital output pins will be driven. The boundary scan register will be connected between
JTDI and JTDO. The Capture-DR will sample all digital inputs into the boundary scan register.
CLAMP
All digital outputs of the device will output data from the boundary scan parallel output while connecting
the bypass register between JTDI and JTDO. The outputs will not change during the CLAMP instruction.
HIGHZ
All digital outputs of the device will be placed in a high-impedance state. The BYPASS register will be
connected between JTDI and JTDO.
DS26502 T1/E1/J1/64KCC BITS Element
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IDCODE
When the IDCODE instruction is latched into the parallel instruction register, the identification test
register is selected. The device identification code will be loaded into the identification register on the
rising edge of JTCLK following entry into the capture-DR state. Shift-DR can be used to shift the
identification code out serially via JTDO. During test-logic-reset, the identification code is forced into the
instruction register’s parallel output. The ID code will always have a 1 in the LSB position. The next 11
bits identify the manufacturer’s JEDEC number and number of continuation bytes followed by 16 bits for
the device and 4 bits for the version Table 17-2. Table 17-3 lists the device ID codes.
Table 17-2. ID Code Structure
MSB LSB
Version
Contact Factory Device ID JEDEC 1
4 bits 16 bits 00010100001 1
Table 17-3. Device ID Codes
DEVICE 16-BIT ID
DS26502 0035h
17.2 Test Registers
IEEE 1149.1 requires a minimum of two test registers: the bypass register and the boundary scan register.
An optional test register has been included with the DS26502 design. This test register is the
identification register and is used with the IDCODE instruction and the test-logic-reset state of the TAP
controller.
17.2.1 Boundary Scan Register
This register contains both a shift register path and a latched parallel output for all control cells and
digital I/O cells and is n bits in length. See for all the cell bit locations and definitions.
17.2.2 Bypass Register
This is a single 1-bit shift register used with the BYPASS, CLAMP, and HIGHZ instructions that
provides a short path between JTDI and JTDO.
17.2.3 Identification Register
The identification register contains a 32-bit shift register and a 32-bit latched parallel output. This register
is selected during the IDCODE instruction and when the TAP controller is in the test-logic-reset state.
DS26502 T1/E1/J1/64KCC BITS Element
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Table 17-4. Boundary Scan Control Bits
CELL # NAME TYPE CONTROL
CELL
0 AD1 Output3 1
1 AD1_7_CTRL Controlr
2 AD0 Output3 3
3 AD0_CTRL Controlr
4 WR_RW observe_only
5 RD_DS observe_only
6 CS observe_only
7 BIS1 observe_only
8 BIS0 observe_only
9 BTS observe_only
10 THZE observe_only
11 TMODE1 observe_only
12 TMODE2 observe_only
13 PLL_CLK observe_only
14 INT Output3 15
15 INT_CTRL Controlr
16 TSTRST observe_only
17 RLOS observe_only
18 TCSS1 observe_only
19 RLOF_CCE observe_only
20 RAIS observe_only
21 RSER observe_only
22 OUT_400HZ observe_only
23 RS_8K observe_only
24 RCLK observe_only
25 TS_8K_4 Output3 26
26 TS_8K_4_CTRL Controlr
27 TSER observe_only
28 TPOSO observe_only
DS26502 T1/E1/J1/64KCC BITS Element
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CELL # NAME TYPE CONTROL
CELL
29 TNEGO observe_only
30 TCLKO observe_only
31 TCLK observe_only
32 ALE_A7 observe_only
33 A6 observe_only
34 A5 observe_only
35 A4 observe_only
36 A3 observe_only
37 A2 observe_only
38 A1 observe_only
39 A0 observe_only
40 AD7 Output3 1
41 AD6 Output3 1
42 AD5 Output3 1
43 AD4 Output3 1
44 AD3 Output3 1
45 AD2 Output3 1
DS26502 T1/E1/J1/64KCC BITS Element
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18. FUNCTIONAL TIMING DIAGRAMS
18.1 Processor Interface
18.1.1 Parallel Port Mode
See the AC Timing section.
18.1.2 SPI Serial Port Mode
Figure 18-1. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 0
Figure 18-2. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 0
Figure 18-3. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 1
1 A7
0 0 0 0 0 0
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
LSB MSB
SCK
C
S
MOSI
MISO
B
A6 A5 A4 A3 A2 A1
LSBMSB
A0
SCK
C
S
1 A7
0 0 0 0 0 0
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
LSB MSB
MOSI
MISO
B
A6 A5 A4 A3 A2 A1
LSBMSB
A0
SCK
C
S
1 A7
0 0 0 0 0 0
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
LSB MSB
MOSI
MISO
B
A6 A5 A4 A3 A2 A1
LSBMSB
A0
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 18-4. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 1
Figure 18-5. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 0
Figure 18-6. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 0
SCK
C
S
1 A7
0 0 0 0 0 0
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
LSB MSB
MOSI
MISO
B
A6 A5 A4 A3 A2 A1
LSBMSB
A0
0 0
LSB MSB
SCK
C
S
MOSI
MISO
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
A4 A3 A2 A1 A0
LSBMSB
0 0 0 0 0 A7 A6 A5 B
SCK
C
S
0 0
LSB MSB
MOSI
MISO
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
A4 A3 A2 A1 A0
LSBMSB
0 0 0 0 0 A7 A6 A5 B
DS26502 T1/E1/J1/64KCC BITS Element
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Figure 18-7. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 1
Figure 18-8. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 1
SCK
C
S
0 0
LSB MSB
MOSI
MISO
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
A
4
A
3
A
2
A
1
A
0
LSBMSB
0 0 0 0 0
A
7
A
6
A
5B
SCK
C
S
0 0
LSB MSB
MOSI
MISO
D7 D6 D5 D4 D3 D2 D1 D0
LSBMSB
A
4
A
3
A
2
A
1
A
0
LSBMSB
0 0 0 0 0
A
7
A
6
A
5B
DS26502
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19. OPERATING PARAMETERS
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to Ground………………………………………………………-1.0V to +6.0V
Operating Temperature Range for DS26502L…………………………………………………………0°C to +70°C
Operating Temperature Range for DS26502LN……………………………………………-40°C to +85°C (Note 1)
Storage Temperature Range………………………………………………………………………...-55°C to +125°C
Soldering Temperature……………………………………… ………….….See IPC/JEDEC J-STD-20 Specification
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation
sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect reliability.
Note 1: Specifications to -40°C are guaranteed by design (GBD) and not production tested.
Table 19-1. Thermal Characteristics
PARAMETER MIN TYP MAX NOTES
Ambient Temperature -40°C +85°C 2
Junction Temperature +125°C
Theta-JA (θJA) in Still Air +46.3°C/W 3
Table 19-2. Theta-JA (θJA) vs. Airflow
FORCED AIR
(meters per second) THETA-JA (θJA)
0 +45.3°C/W
1 +37.2°C/W
2.5 +34.4°C/W
Note 2: The package is mounted on a four-layer JEDEC standard test board.
Note 3: Theta-JA (θJA) is the junction-to-ambient thermal resistance, when the package is mounted on a
four-layer JEDEC standard test board.
Table 19-3. Recommended DC Operating Conditions
(TA = 0°C to +70°C for DS26502L; TA = -40°C to +85°C for DS26502LN.) (Note 4)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Logic 1 VIH 2.0 5.5 V 4
Logic 0 VIL -0.3 +0.8 V 4
Supply VDD 3.135 3.3 3.465 V 5
Note 4: Guaranteed by design (GBD).
Note 5: Applies to RVDD, TVDD, and DVDD.
Table 19-4. Capacitance
(TA = +25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Input Capacitance CIN 5 pF
Output Capacitance COUT 7 pF
DS26502
111 of 125
Table 19-5. DC Characteristics
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26502L; VDD = 3.3V ±5%, TA = -40°C to +85°C for
DS26502LN.)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Supply Current IDD 85 150 mA
Input Leakage IIL -1.0 +1.0
μA 6
Output Leakage ILO 1.0
μA 7
Output Current (2.4V) IOH -1.0 mA
Output Current (0.4V) IOL +4.0 mA
Note 6: 0.0V < VIN < VDD
Note 7: Applied to INT when three-stated.
DS26502 T1/E1/J1/64KCC BITS Element
112 of 125
20. AC TIMING PARAMETERS AND DIAGRAMS
Capacitive test loads are 40pF for bus signals and 20pF for all others.
20.1 Multiplexed Bus
Table 20-1. AC Characteristics, Multiplexed Parallel Port
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26502L; VDD = 3.3V ±5%, TA = -40°C to +85°C for
DS26502LN.) (Note 1, Figure 20-1, Figure 20-2, and Figure 20-3)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Cycle Time tCYC 200 ns
Pulse Width, DS Low or RD High PWEL 100 ns
Pulse Width, DS High or RD Low PWEH 100 ns
Input Rise/Fall Times tR, tF 20 ns
R/W Hold Time tRWH 10 ns
R/W Setup Time Before DS High tRWS 50 ns
CS Setup Time Before DS, WR, or
RD Active tCS 20 ns
CS Hold Time tCH 0 ns
Read-Data Hold Time tDHR 10 50 ns
Write-Data Hold Time tDHW 5 ns
Muxed Address Valid to AS or
ALE Fall tASL 15 ns
Muxed Address Hold Time tAHL 10 ns
Delay Time DS, WR, or RD to AS
or ALE Rise tASD 20 ns
Pulse Width AS or ALE High PWASH 30 ns
Delay Time, AS or ALE to DS,
WR, or RD tASED 10 ns
Output Data Delay Time from DS
or RD tDDR 80 ns
Data Setup Time tDSW 50 ns
Note 1: The timing parameters in this table are guaranteed by design (GBD).
DS26502 T1/E1/J1/64KCC BITS Element
113 of 125
Figure 20-1. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 00)
Figure 20-2. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 00)
ASH
PW
tCYC
tASD
tASD PW
PW
EH
EL
t
t
t
t
t
t
AHL
CH
CS
ASL
ASED
CS
AD0-AD7
DHR
tDDR
ALE
RD
WR
ASH
PW
tCYC
tASD
tASD PW
PW
EH
EL
t
t
t
t
t
t
t
AHL DSW
DHW
CH
CS
ASL
ASED
CS
AD0-AD7
RD
WR
ALE
DS26502 T1/E1/J1/64KCC BITS Element
114 of 125
Figure 20-3. Motorola Bus Timing (BTS = 1 / BIS[1:0] = 00)
t
A
SD
A
SH
PW
t
t
A
SL
A
HL tCS
t
A
SL
t
t
t
DSW
DHW
t
CH
tt
t
DDR DHR
RWH
t
A
SED PW
EH
tRWS
A
HL
PW
EL tCYC
A
S
D
S
A
D0-AD7
(write)
A
D0-AD7
(read)
R
/
W
C
S
A
8 & A9
DS26502
115 of 125
20.2 Nonmultiplexed Bus
Table 20-2. AC Characteristics, Non-Mux Parallel Port
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26502L; VDD = 3.3V ±5%, TA = -40°C to +85°C for
DS26502LN.) (Note 1, Figure 20-4, Figure 20-5, Figure 20-6, and Figure 20-7)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Setup Time for A0 to A7, Valid to
CS Active t1 0 ns
Setup Time for CS Active to
Either RD, WR, or DS Active t2 0 ns
Delay Time from Either RD or
DS Active to Data Valid t3 75 ns
Hold Time from Either RD, WR,
or DS Inactive to CS Inactive t4 0 ns
Hold Ti me fr om CS Inactive to
Data Bus Three-State t5 5 20 ns
Wait Time from Either WR or DS
Activate to Latch Data t6 75 ns
Data Setup Time to Either WR or
DS Inactive t7 10 ns
Data Hold Time from Either WR
or DS Inactive t8 10 ns
Address Hold from Either WR or
DS Inactive t9 10 ns
Note 1: The timing parameters in this table are guaranteed by design (GBD).
DS26502 T1/E1/J1/64KCC BITS Element
116 of 125
Figure 20-4. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 01)
Figure 20-5. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 01)
A
ddress Valid
Data Valid
A
0 to A7
D0 to D7
W
R
C
S
R
D
0ns min
0ns min
75ns max
0ns min
5ns min/20ns max
t1
t2 t3 t4
t5
Address Valid A0 to A7
D0 to D7
R
D
C
S
W
R
0ns min
0ns min 75ns min
0ns min
10ns
min
10ns
min
t1
t2 t6 t4
t7 t8
DS26502 T1/E1/J1/64KCC BITS Element
117 of 125
Figure 20-6. Motorola Bus Read Timing (BTS = 1 / BIS[1:0] = 01)
Figure 20-7. Motorola Bus Write Timing (BTS = 1 / BIS[1:0] = 01)
Address Valid
Data Valid
A0 to A7
D0 to D7
R/
W
C
S
D
S
0ns min.
0ns min.
75ns max.
0ns min.
5ns min. / 20ns max.
t1
t2 t3 t4
t5
Address Valid A0 to A7
D0 to D7
R/
W
C
S
D
S
0ns min.
0ns min. 75ns min.
0ns min.
10ns
min.
10ns
min.
t1
t2 t6 t4
t7 t8
DS26502 T1/E1/J1/64KCC BITS Element
118 of 125
20.3 Serial Bus
Table 20-3. AC Characteristics, Serial Bus
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26502L; VDD = 3.3V ±5%, TA = -40°C to +85°C for
DS26502LN.) (Note 1, Figure 20-8 and Figure 20-9)
CHARACTERISTIC (NOTE 3) SYMBOL MIN MAX UNITS DIAGRAM
NUMBER
(NOTE 2)
Operating Frequency
Slave fBUS(S) 10 MHz
1 Cycle Time: Slave tCYC(S) 100 ns
2 Enable Lead Time tLEAD(S) 15 ns
3 Enable Lag Time tLAG(S) 15 ns
4 Clock (CLK) High Time
Slave tCLKH(S) 50 ns
5 Clock (CLK) Low Time
Slave tCLKL(S) 50 ns
6 Data Setup Time (inputs)
Slave tSU(S) 5 ns
7 Data Hold Time (inputs)
Slave tH(S) 15 ns
CPHA = 0 tA(CP0) 0 40
8 Access Time, Slave
(Note 4) CPHA = 1 tA(CP1) 0 20
ns
9 Disable Time, Slave (Note 5) tDIS(S) 25 ns
10 Data Valid Time, After Enable Edge
Slave (Note 6) tV(S) 40 ns
11 Data Hold Time, Outputs, After Enable Edge
Slave tHD(S) 5 ns
Note 1: The timing parameters in this table are guaranteed by design (GBD).
Note 2: Numbers refer to dimensions in the following Figure 20-8 and Figure 20-9.
Note 3: All timing is shown with respect to 20% VDD and 70% VDD, unless otherwise noted. 100pF load on all SPI pins.
Note 4: Time to data active from high-impedance state.
Note 5: Hold time to high-impedance state.
Note 6: With 100pF on all SPI pins.
DS26502 T1/E1/J1/64KCC BITS Element
119 of 125
Figure 20-8. SPI Interface Timing Diagram, CPHA = 0, BIS[1:0] = 10
Figure 20-9. SPI Interface Timing Diagram, CPHA = 1, BIS[1:0] = 10
MSB LSB
BITS 6-1
SLAVE LSB
SLAVE MSB BITS 6-1
2
1
3
4
4
5
5
9
11
NOTE
CS
INPUT
CLK INPUT
CPOL = 0
CLK INPUT
CPOL = 1
MISO
OUTPUT
MOSI
INPUT
6 710
8
10
NOTE: NOT DEFINED, BUT USUALLY LSB OF CHARACTER PREVIOUSLY
TRANSMITTED
MSB LSB
BITS 6-1
SLAVE MSB SLAVE LSB
BITS 6-1
2
1 3
4
4
5
5
6 7
8
9
11
11
10
NOTE
CS
INPUT
CLK INPUT
CPOL = 0
CLK INPUT
CPOL = 1
MISO
INPUT
MOSI
OUTPUT
NOTE: NOT DEFINED, BUT USUALLY MSB OF CHARACTER JUST RECEIVED.
DS26502 T1/E1/J1/64KCC BITS Element
120 of 125
20.4 Receive Side AC Characteristics
Table 20-4. Receive Side AC Characteristics
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26502L; VDD = 3.3V ±5%, TA = -40°C to +85°C for
DS26502LN.) (Note 1 and Figure 20-10)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
488 ns 2
648 ns 3
15.6 µs 4
RCLK Period tCP
158.4 ns 5
tCH 200 ns 6
tCL 200 ns 6
tCH 7.5 µs 6
RCLK Pulse Width
tCL 7.5 µs 5
tCH 150 ns 7
tCL 150 ns 7
tCH 7.5 µs 4
RCLK Pulse Width
tCL 7.5 µs 4
RCLK to RSER Delay tD1 20 ns
RCLK to RS_8K, 400Hz Delay tD2 50 ns
Note 1: The timing parameters in this table are guaranteed by design (GBD).
Note 2: E1 mode.
Note 3: T1 or J1 mode.
Note 4: 64KCC mode.
Note 5: 6312kHz mode.
Note 6: Jitter attenuator enabled in the receive path.
Note 7: Jitter attenuator disabled or enabled in the transmit path.
DS26502 T1/E1/J1/64KCC BITS Element
121 of 125
Figure 20-10. Receive Timing, T1, E1, 64KCC Mode
tD1
tD2
RSER
RS_8K1
RCLK
E1 = MSB of Channel 1
T1 = F-Bit
tD2
RS_8K2
tD2
400HZ3
NOTES:
1) RS_8K OUTPUT IN T1 OR E1 MODE.
2) RS_8K OUTPUT IN 64KCC MODE.
3) 400Hz OUTPUT ACTIVE ONLY IN 64KCC MODE, HIGH IMPEDANCE IN
ALL OTHER MODES.
DS26502 T1/E1/J1/64KCC BITS Element
122 of 125
20.5 Transmit Side AC Characteristics
Table 20-5. Transmit Side AC Characteristics
(VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Note 1 and Figure 20-11)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
488 ns 2
648 ns 3
15.6 µs 4
TCLK Period tCP
158.4 ns 5
tCH 75 ns
TCLK Pulse Width tCL 75 ns
TCLK Rise and Fall Times tR, tF 25 ns
TX CLOCK Setup to TSER,
TS_8K_4 tSU 20 ns 6, 7
Delay TX CLOCK to TS_8K_4 tD2 50 ns 7, 8
Delay TCLK to PLL_OUT,
TX CLOCK tD3 3 Ns 7, 9
Delay TCLKO to TPOSO and
TNEGO tDD 50 ns
Note 1: The timing parameters in this table are guaranteed by design (GBD).
Note 2: E1 mode.
Note 3: T1 or J1 mode.
Note 4: 64KCC mode.
Note 5: 6312kHz mode.
Note 6: TS_8K_4 in input mode.
Note 7: TX CLOCK is an internal signal.
Note 8: TS_8K_4 in output mode.
Note 9: TX CLOCK is an internal signal that samples TSER and TS_8K_4 when TS_8K_4 is in input mode.
DS26502 T1/E1/J1/64KCC BITS Element
123 of 125
Figure 20-11. Transmit Timing, T1, E1, 64KCC Mode
TSER
TS_8K_41
tD2
tHD
tSU
TS_8K_42
tSU
tF
t
R
TCLK
t
t
CL
tCH
CP
TX CLOCK3
PLL_OUT
tD3
RCLK, JA CLOCK4
(REFER TO THE TRANSMIT PLL BLOCK DIAGRAM, Figure 3-3.)
NOTE 1: TS_8K_4 IN OUTPUT MODE.
NOTE 2: TS_8K_4 IN INPUT MODE.
NOTE 3: TX CLOCK IS THE INTERNAL CLOCK THAT DRIVES THE TRANSMIT SECTION. THE
SOURCE OF THIS SIGNAL DEPENDS ON THE CONFIGURATION OF THE TRANSMIT PLL. IF TX
CLOCK IS GENERATED BY THE TRANSMIT PLL (CONVERSION FROM ANOTHER CLOCK RATE)
THEN THE USER SHOULD OUTPUT THAT SIGNAL ON THE PLL_OUT PIN AND USE THAT SIGNAL
TO REFERENCE TSER AND TS_8K_4 IF TS_8K_4 IS IN THE INPUT MODE.
NOTE 4: RCLK (THE RECOVERED LINE CLOCK) AND JA CLOCK (AN INTERNAL CLOCK DERIVED
FROM MCLK) MAY BE SELECTED AS THE SOURCE FOR THE TRANSMIT PLL OR USED
UNCONVERTED FOR TX CLOCK.
DS26502
124 of 125
21. REVISION HISTORY
REVISION
DATE DESCRIPTION PAGES
CHANGED
070904 New product release. —
032405
Updated Table 2-1 and Table 2-2.
Updated Figure 3-1.
Replaced the older recommended LIU circuits in Section 13.8 with newer
versions (Figure 13-4 and Figure 13-5, Table 13-1 and Table 13-2)
Added timing information to Table 20-4 and updated Figure 20-11.
081105
Corrected the bit order of the TPCR register (bits 3 and 4 were reversed).
Corrected the polarity for the TAIS pin description in hardware operation
mode.
Added values to Table 19-2.
101805
Changed Section 13.4 to read “2.048 x 2N (where N = 1 to 3)” instead of
“2.048 x N (where N = 1 to 4)”
Edited Figure 3-4 to show 12.8MHz clock option and added references
throughout relevant sections of the document.
Added JACKS1 bit to LIC2.7—This feature is available in Rev B1 and later.
020906
Section 13.3.1, Section 13.3.2, SR1 Bits 1 and 2: Clarified the open circuit and
short circuit wording.
Added package drawing link to Package Information section, along with
updated package drawing.
Removed reference to E1RCR and E1TCR bit 3 (this bit functionality
has been moved to the MCREG). 48
053107 Replaced Figure 13-4 and Figure 13-5 to show 10μF cap on TTIP. 90, 91
100507
In the Absolute Maximum Ratings (Section 19), added Note 1:
Specifications at -40
°
C are guaranteed by design GBD and not
production tested. to Operating Temp Range for DS26502LN.
Renumbered notes for Table 19-1 to Table 19-5.
111, 112
Clarified RITD and TITD descriptions. 16
For E1TS description, changed 0 = 120Ω and 1 = 75Ω to 0 = 75Ω and
1 = 120Ω. 19
121707
Corrected Note 2 in the LIC1[7:5] register description to include TT2
along with TT0 and TT1. 82
042208 In Section 13, corrected the wording to clearly indicate that different
transformers are required for T1, J1, E1, and 6312kHz modes and for
64KCC mode. 77
DS26502
125 of 125
Maxim/Dallas Semiconductor cannot assume responsibili ty for use of any circuitry other than circuitry entirely embodied in a Maxim/Dal las Semiconductor product.
No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2008 Maxim Integrated Products
The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation.
22. PACKAGE INFORMATION
(The package drawing(s) in this data sheet may not reflect the most current specifications. The package number
provided for each package is a link to the latest package outline information.)
22.1 64-Pin LQFP (56-G4019-001)
