DESCRIPTION
The 78Q2123 and 78Q2133, MicroPHYTM, are the
smallest 10BASE-T/100BASE-TX Fast Ethernet
transceivers in the market. They include integrated
MII, ENDECs, scrambler/descrambler, dual-speed
clock recovery, and full-featured auto-negotiation
functions. The transmitter includes an on-chip pulse-
shaper and a low-power line driver. The receiver has
an adaptive equalizer and a baseline restoration
circuit required for accurate clock and data recovery.
The transceiver interfaces to Category-5 unshielded
twisted pair (Cat-5 UTP) cabling for 100BASE-TX
applications, and Category-3 unshielded twisted pair
(Cat-3 UTP) for 10BASE-T applications. The MDI is
connected to the line media via dual 1:1 isolation
transformers. No external filter is required. Interface
to the MAC is accomplished through an IEEE-802.3
compliant Media Independent Interface (MII). The
78Q2123/78Q2133 are intended to serve the
embedded Ethernet market, tailored specifically to the
needs of game consoles, broadband modems,
printers, set top boxes and audio/visual equipment. It
is designed for low-power consumption and operates
from a single 3.3V supply. The 78Q2123 is rated for
commercial temperature range and the 78Q2133 is
rated for industrial temperature range.
FEATURES
xSmallest 10/100 PHY available
x10BASE-T/100BASE-TX IEEE-802.3 compliant
TX and RX functions requiring a dual 1:1 isolation
transformer interface to the line
xIntegrated MII, 10BASE-T/100BASE-TX ENDEC,
100BASE-TX scrambler/descrambler, and
full-featured auto-negotiation function
xFull duplex operation capable
xAutomatic MDI/MDI-X cross over correction
xRegister-programmable transmit amplitude
xAutomatic polarity correction during auto-
negotiation and 10BASE-T signal reception
xPower-saving and power-down modes including
transmitter disable
x2 Programmable LED indicators (Link and
Activity by default)
xUser programmable Interrupt pin
x
Packages:
32-QFN (5x5 mm) and 32-TQFN (5x5mm)
xLow Power (~290mW)
xSingle 3.3 V r0.3V Supply
x78Q2123 rated for 0°C to 70°C operation
x78Q2133 rated for -40°C to 85°C operation
RXC
TXC
RXD
TXD
SMI
MII
100M
10M
Scrambler,
Parallel/Serial
Parallel/Serial,
Manchester Encoder
MRZ/NRZI
MLT3 Encoder
TX CLK GEN
Auto
Auto
MDI-X
Mux
Tx/Rx
Rx/Tx
Carrier Sense,
Collision Detect
CLK
Recovery
10M
100M
Adaptive EQ,
Baseline Wander Correct,
MLT3 Decode, NRZI/NRZ
Clock Reference LEDs
CLKIN 25MHz
Link
Act
Rev. 2.0 1
DATA SHEET
78Q2123/78Q2133 MicroPHY
10/100BASE-TX Transceiver
SimplifyingSystemIntegration
TM
Pulse Shaper
and Filter
Manchester Decoder,
Parallel/Serial
MII
Registers Serial/Parallel
Descrambler,
5B/4B Decoder
78Q2123/78Q2133 Data Sheet DS_21x3_001
Table of Contents
1 Functional Description .......................................................................................................................... 5
1.1
General
........................................................................................................................................... 5
1.1.1 Power Management............................................................................................................ 5
1.1.2 Analog Biasing and Supply Regulation................................................................................ 5
1.1.3 Clock Selection.................................................................................................................... 5
1.1.4 Transmit Clock Generation.................................................................................................. 5
1.1.5 Receive Signal Qualification................................................................................................ 6
1.1.6 Receive Clock Recovery ..................................................................................................... 6
1.2
100BASE-TX OPERATION........................................................................................................... 6
1.2.1 100BASE-TX Transmit........................................................................................................ 6
1.2.2 100BASE-TX Receive......................................................................................................... 6
1.2.3 PCS Bypass Mode (Auto-negotiate must be off)................................................................. 6
1.3
10BASE-T OPERATION ............................................................................................................... 7
1.3.1 10BASE-T Transmit ............................................................................................................ 7
1.3.2 10BASE-T Receive ............................................................................................................. 7
1.3.3 Polarity Correction............................................................................................................... 7
1.3.4 SQE TEST .......................................................................................................................... 7
1.3.5 Natural Loopback ................................................................................................................ 7
1.3.6 Repeater Mode ................................................................................................................... 7
1.4
Auto-Negotiation
............................................................................................................................ 8
1.5
MediaIndependentInterface
......................................................................................................... 9
1.5.1 MII Transmit and Receive Operation................................................................................... 9
1.5.2 Station Management Interface ............................................................................................ 9
1.6
AdditionalFeatures
......................................................................................................................10
1.6.1 LED Indicators...................................................................................................................10
1.6.2 Interrupt Pin.......................................................................................................................10
1.6.3 Automatic MDI/ MDI-X Configuration ................................................................................10
2 Pin Description.....................................................................................................................................11
2.1
Legend
..........................................................................................................................................11
2.2
MII (Media Independent Interface)
..............................................................................................11
2.3
Control and Status
.......................................................................................................................12
2.4
MDI (Media Dependent Interface)
...............................................................................................12
2.5
Oscillator/Clock
............................................................................................................................12
2.6
Power Supply and Ground
...........................................................................................................12
2.7
LED Signals (Programmability Is Secondary Requirement)
......................................................13
3 Register Description...........................................................................................................................14
3.1
MR0: Control Register
.................................................................................................................15
3.2
MR1: Status Register
...................................................................................................................16
3.3
MR2: PHY Identifier Register 1
...................................................................................................17
3.4
MR3: PHY Identifier Register 2
...................................................................................................17
3.5
MR4: Auto-Negotiation Advertisement Register
.........................................................................17
3.6
MR5: Auto-Negotiation Link Partner Ability Register
................................................................18
3.7
MR6: Auto-Negotiation Expansion Register
...............................................................................18
3.8
MR16: Vendor Specific Register
.................................................................................................18
3.9
MR17: Interrupt Control/Status Register
.....................................................................................20
3.10
MR18: DiagnosticRegister
..........................................................................................................21
3.11
MR19: Transceiver Control
.........................................................................................................21
3.12
MR20:Reserved
..........................................................................................................................21
3.13
MR21:Reserved
..........................................................................................................................21
3.14
MR22:Reserved
..........................................................................................................................21
3.15
MR23: LED Configuration Register
.............................................................................................22
3.16
MR24: MDI/MDIX Control Register
.............................................................................................22
2
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4 Electrical Specifications......................................................................................................................23
4.1
AbsoluteMaximum Ratings
.........................................................................................................23
4.2
RecommendedOperatingConditions
.........................................................................................23
4.3
DCCharacteristics
.......................................................................................................................23
4.4
Digital I/O Characteristics
............................................................................................................24
4.5
Digital Timing Characteristics
......................................................................................................25
4.5.2 MII Transmit Interface .......................................................................................................25
4.5.3 MII Receive Interface.........................................................................................................26
4.6
MDIO Interface Input Timing
........................................................................................................26
4.6.1 MDIO Interface Output Timing ..........................................................................................27
4.6.2 MDIO Interface Output Timing ..........................................................................................28
4.6.3 100BASE-TX System Timing ............................................................................................29
4.6.4 10BASE-T System Timing.................................................................................................29
4.7
Analog Electrical Characteristics
.................................................................................................30
4.7.1 100BASE-TX Transmitter..................................................................................................30
4.7.2 100BASE-TX Transmitter (Informative).............................................................................30
4.7.3 100BASE-TX Receiver......................................................................................................30
4.7.4 10BASE-T Transmitter ......................................................................................................31
4.7.5 10BASE-T Transmitter (Informative) .................................................................................31
4.7.6 10BASE-T Receiver ..........................................................................................................31
4.8
Isolation Transformers .................................................................................................................33
4.9
ReferenceCrystal
.........................................................................................................................33
4.9.1 External XTLP Oscillator Characteristics...........................................................................34
5 Package Pin Designations ..................................................................................................................35
6 Package Information............................................................................................................................36
7 Ordering Information...........................................................................................................................36
Revision History...........................................................................................................................................37
3
78Q2123/78Q2133 Data Sheet DS_21x3_001
Figures
Figure 1: RST Pulse Duration ...........................................................................................................................25
Figure 2: Transmit Inputs to the 78Q2123/78Q2133........................................................................................25
Figure 3: Receive Outputs from the 78Q2123/78Q2133 .................................................................................26
Figure 4: MDIO as an Input to the 78Q2123/78Q2133 ....................................................................................26
Figure 5: MDIO as an Output to the 78Q2123/78Q2133............................................................................. 27
Figure 6: MDIO Interface Output Timing...................................................................................................... 28
Figure 7: Application Diagram for 78Q2123/78Q2133 .....................................................................................32
Figure 8: External XTLP Oscillator Characteristics ...................................................................................... 34
Figure 9: Package Pin Designations.................................................................................................................35
4
DS_21x3_001 78Q2123/78Q2133 Data Sheet
1 Functional Description
1.1
General
1.1.1 Power Management
The 78Q2123 and 78Q2133 have three power saving modes:
xChip Power-Down
xReceive Power Management
xTransmit High Impedance Mode
Chip power-down is activated by setting the PWRDN bit in MII register MR0.11. When the chip is in
power-down mode, all on-chip circuitry is shut off, and the device consumes minimum power. While in
the power-down state, the 78Q2123/78Q2133 still respond to management transactions.
Receive power management (RXCC mode) is activated by setting the RXCC bit in MII register MR16.0.
In this mode of operation, the adaptive equalizer, the clock recovery phase lock loop (PLL), and all other
receive circuitry will be powered down when no valid MLT-3 signal is present at the UTP receive line
interface. As soon as a valid signal is detected, all circuits will automatically be powered up to resume
normal operation. During this mode of operation, RX_CLK will be inactive when there is no data being
received. Note that the RXCC mode is not supported during 10BASE-T operation.
Transmit high impedance mode is activated by setting the TXHIM bit in MII register MR16.12. In this
mode of operation, the transmit UTP drivers are in a high impedance state and TX_CLK is tri-stated. A
weak internal pull-up is enabled on TX_CLK. The receive circuitry remains fully operational. The default
state of MR16.12 is a logic low for disabling the transmit high impedance mode. Only a reset condition will
automatically clear MR16.12. The transmitter is fully functional when MR16.12 is cleared. This feature is
useful when configuring a system for Wake-On LAN (when the 78Q2123/78Q2133 are coupled with a
Wake-On LAN capable MAC).
1.1.2 Analog Biasing and Supply Regulation
The 78Q2123/78Q2133 require no external component to generate on-chip bias voltages and currents.
High accuracy is maintained through a closed-loop trimmed biasing network.
On-chip digital logic runs off an internal voltage regulator. Hence only a single 3.3V (r0.3V) supply is
required to power-up the device. The on-chip regulator is not affected by the power-down mode.
1.1.3 Clock Selection
The 78Q2123/78Q2133 have an on-chip crystal oscillator which can also be driven by an external oscillator.
In this mode of operation, a 25 MHz crystal should be connected between the XTLP and XTLN pins.
Alternatively, an external 25 MHz clock input can be connected to the XTLP pin. In this mode of operation,
a crystal is not required and the XTLN pin must be tied to ground.
1.1.4 Transmit Clock Generation
The transmitter uses an on-chip frequency synthesizer to generate the transmit clock. In 100BASE-TX
operation, the synthesizer multiplies the reference clock by 5 to obtain the internal 125 MHz serial transmit
clock. In 10BASE-T mode, it generates an internal 20MHz transmit clock by multiplying the reference
25 MHz clock by 4/5. The synthesizer references either the local 25 MHz crystal oscillator, or the externally
applied clock, depending on the selected mode of operation.
5
78Q2123/78Q2133 Data Sheet DS_21x3_001
1.1.5 Receive Signal Qualification
The integrated signal qualifier has separate squelch and unsquelch thresholds. It also includes a built-in timer
to ensure fast and accurate signal detection and line noise rejection. Upon detection of two or more valid
10BASE-T or 100BASE-TX pulses on the line receive port, signal detect is indicated. The signal detect
threshold is then lowered by about 40%. All adaptive circuits are released from their initial states and allowed
to lock onto the incoming data. In 100BASE-TX operation, signal detect is de-asserted when no signal is
presented for a period of about 1.2 μs. In 10BASE-T operation, signal detect is de-asserted whenever no
Manchester data is received. In either case, the signal detect threshold will return to the squelched level
whenever the signal detect indication is de-asserted. Signal detect is also used to control the operation of the
clock/data recovery circuit to assure fast acquisition.
1.1.6 Receive Clock Recovery
In 100BASE-TX mode, the 125 MHz receive clock is extracted using a digital DLL-based loop. When no
receive signal is present, the CDR is directed to lock onto the 125 MHz transmit serial clock. When signal
detect is asserted, the CDR will use the received MLT-3 signal as the clock reference. The recovered clock is
used to re-time the data signal and for conversion of the data to NRZ format.
In 10BASE-T mode, the 20 MHz receive clock is recovered digitally from the Manchester data using a
DLL locked to the reference clock. When Manchester-coded preambles are detected, the CDR
immediately re-aligns the phase of the clock to synchronize with the incoming data. Hence clock
acquisition is fast and immediate.
1.2
100BASE-TX OPERATION
1.2.1 100BASE-TX Transmit
The 78Q2123/78Q2133 contain all of the necessary circuitry to convert the transmit MII signaling from a
MAC to an IEEE-802.3 compliant data-stream driving Cat-5 UTP cabling. The internal PCS interface
maps 4 bit nibbles from the MII to 5 bit code groups as defined in Table 24-1 of IEEE-802.3. These 5 bit
code groups are then scrambled and converted to a serial stream before being sent to the MLT-3 pulse
shaping circuitry and line driver. The pulse-shaper uses current modulation to produce the desired output
waveform. Controlled rise/fall time in the MLT-3 signal is achieved using an accurately controlled voltage
ramp generator. The line driver requires an external 1:1 isolation transformer to interface with the line
media. The center-tap of the primary side of the transformer must be connected to the Vcc supply (3.3V
r0.3V).
1.2.2 100BASE-TX Receive
The 78Q2123/78Q2133 receive a 125MBaud MLT-3 signal through a 1:1 transformer. The signal then
goes through a combination of adaptive offset adjustment (baseline wander correction) and adaptive
equalization. The effect of these circuits is to sense the amount of dispersion and attenuation caused by
the cable and transformer, and restore the received pulses to logic levels. The amount of gain and
equalization applied to the pulses varies with the detected attenuation and dispersion and, therefore, with
the length of the cable. The 78Q2123/78Q2133 can compensate for cable loss of up to 10dB at 16 MHz.
This loss is represented as test_chan_5 in Annex A of the ANSI X3.263:199X. The equalized MLT-3 data
signal is bi-directionally sliced and the resulting NRZI bit-stream is presented to the CDR where it is
re-timed and decoded to NRZ format. The re-timed serial data passes through a serial-to-parallel
converter, then descrambled and aligned into 5 bit code groups. The receive PCS interface maps these
code groups to 4 bit data for the MII as outlined in Table 24-1 in Clause 24 of IEEE-802.3.
1.2.3 PCS Bypass Mode (Auto-negotiate must be off)
The PCS Bypass mode is entered by setting register bit MR 16.1. In this mode the 78Q2123/78Q2133
accept scrambled 5 bit code words at the TX_ER and TXD[3:0] pins, TX_ER being the MSB of the data
input. The 5 bit code groups are converted to MLT-3 signal for transmission.
6
DS_21x3_001 78Q2123/78Q2133 Data Sheet
The received MLT-3 signal is converted to 5 bit NRZ code groups and output from the RX_ER and
RXD[3:0] pins, RX_ER being the MSB of the data output. The RX_DV and TX_EN pins are unused in
PCS Bypass mode.
1.3
10BASE-T OPERATION
1.3.1 10BASE-T Transmit
The 78Q2123/78Q2133 take 4-bit parallel NRZ data via the MII interface and passes it through a parallel
to serial converter. The data is then passed through a Manchester encoder, pre-emphasis pulse-shaper,
media filter, and finally to the twisted-pair line driver. The pulse-shaper and filter ensure the output
waveforms meet the voltage template and spectral content requirements detailed in Clause 14 of
IEEE-802.3. Interface to the twisted-pair media is through a center-tapped 1:1 transformer. No external
filtering is required. During auto-negotiation and 10BASE-T idle periods, link pulses are transmitted.
The 78Q2123/78Q2133 employ an onboard timer to prevent the MAC from capturing a network through
excessively long transmissions. When this timer expires, the chip enters the jabber state and
transmission is halted. The jabber state is exited after the MII goes idle for 500r250 ms.
1.3.2 10BASE-T Receive
The 78Q2123/78Q2133 receive Manchester-encoded 10BASE-T data through the twisted pair inputs and
re-establishes logic levels through a slicer with a smart squelch function. The slicer automatically adjusts
its level after detection of valid data with the appropriate levels. Data is passed on to the CDR where the
clock is recovered, and the data is re-timed and decoded. From there, data enters the serial-to-parallel
converter for transmission to the MAC via the Media Independent Interface. Interface to the twisted-pair
media is through an external 1:1 transformer. Polarity information is detected and corrected within
internal circuitry.
1.3.3 Polarity Correction
The 78Q2123/78Q2133 are capable of either automatic or manual polarity reversal for 10BASE-T and
auto-negotiation functions. Register bits MR16.5 and MR16.4 control this feature. The default is
automatic mode where MR16.5 is low and MR16.4 indicates if the detection circuitry has inverted the
input signal. To enter manual mode, MR16.5 should be set high and MR16.4 will then control the signal
polarity.
1.3.4 SQE TEST
The 78Q2123/78Q2133 support the Signal Quality Error (SQE) function detailed in IEEE-802.3. At an
interval of 1Ps after each negative transition of the TX_EN pin in 10BASE-T mode, the COL pin will go
high for a period of 1 Ps. SQE is not signaled during transmission after collision is detected. SQE is
automatically disabled when repeater mode is enabled. This function can be disabled through register bit
MR16.11.
1.3.5 Natural Loopback
When enabled, whenever the 78Q2123/78Q2133 are transmitting and not receiving on the twisted pair
media (10BASE-T Half Duplex mode), data on the TXD3-0 pins are looped back onto the RXD3-0 pins.
During a collision, data from the RXI pins is routed to the RXD3-0 pins. The natural loopback function is
enabled through register bit MR16.10. This feature is off by default.
1.3.6 Repeater Mode
When register bit MR16.15 is set, the 78Q2123/78Q2133 are placed in repeater mode. In this mode, full
duplex operation is prohibited, CRS responds only to receive activity and, in 10BASE-T mode, the SQE
test function is disabled.
7
78Q2123/78Q2133 Data Sheet DS_21x3_001
1.4
Auto-Negotiation
The 78Q2123/78Q2133 support the auto-negotiation functions of Clause 28 of IEEE-802.3 for 10/100
Mbps operation over copper wiring. This function can be enabled via register settings. The
auto-negotiation function defaults to ON and bit MR0.12 (ANEGEN) is high after reset. Software can
disable the auto-negotiation function by writing to bit MR0.12.
The contents of register MR4 are sent to the 78Q2123/78Q2133’s link partner during auto-negotiation via
fast link pulse coding.
The default values of the auto-negotiation registers are set as follows:
Register.Bits Function Default Value
0.13 Speed Select 1 (100 BASE TX)
0.12 AN Enable 1 (enabled)
0.8 Duplex 1 (full duplex)
4.8/1.14 100BASE-TX
Full Duplex
1
4.7/1.13 100 BASE-TX 1
4.6/1.12 10 BASE-T
Full Duplex
1
4.5/1.11 10 BASE-T 1
These default values can be changed by writing different values to the registers, then restarting
auto-negotiation.
With auto-negotiation enabled, the 78Q2123/78Q2133 will start sending fast link pulses at power on, loss
of link or upon a command to restart. At the same time, it will look for either 10BASE-T idle, 100BASE-TX
idle, or fast link pulses from its link partner. If either idle pattern is detected, the 78Q2123/78Q2133
configure themselves in half-duplex mode at the appropriate speed. If it detects fast link pulses, it
decodes and analyzes the link code transmitted by the link partner. When three identical link code words
are received (ignoring the acknowledge bit) the link code word is stored in register MR5. Upon receiving
three more identical link code words, with the acknowledge bit set, the 78Q2123/78Q2133 configure
themselves to the highest priority technology common to the two link partners. The technology priorities
are, in descending order:
100BASE-TX, Full Duplex
100BASE-TX, Half Duplex
10BASE-T, Full Duplex
10BASE-T, Half Duplex
Once auto-negotiation is complete, register bits MR18.11:10 will reflect the actual speed and duplex that
was chosen.
If auto-negotiation fails to establish a link for any reason, register bit MR18.12 will reflect this and auto
negotiation will restart from the beginning. Writing a ‘1’ to bit MR0.9 (RANEG) will also cause
auto-negotiation to restart.
8
DS_21x3_001 78Q2123/78Q2133 Data Sheet
1.5
MediaIndependentInterface
1.5.1 MII Transmit and Receive Operation
The MII interface on the 78Q2123/78Q2133 provide independent transmit and receive paths for both
10Mb/s and 100Mb/s data rates as described in Clause 22 of the IEEE-802.3 standard.
The transmit clock, TX_CLK, provides the timing reference for the transfer of TX_EN, TXD3-0, and
TX_ER signals from the MAC to the 78Q2123/78Q2133. TXD3-0 is captured on the rising edge of
TX_CLK when TX_EN is asserted. TX_ER is also captured on the rising edge of TX_CLK and is
asserted by the MAC to request that an error code group is to be transmitted. The assertion of TX_ER is
ignored when the 78Q2123/78Q2133 are operating in 10BASE-T mode.
The receive clock, RX_CLK, provides the timing reference to transfer RX_DV, RXD3-0, and RX_ER
signals from the 78Q2123/78Q2133 to the MAC. RX_DV transitions synchronously with respect to
RX_CLK and is asserted when the 78Q2123/78Q2133 are presenting valid data on RXD3-0. RX_ER is
asserted and is synchronous to RX_CLK when a code group violation has been detected in the current
receive packet.
1.5.2 Station Management Interface
The station management interface consists of circuitry which implements the serial protocol as described
in Clause 22.2.4.4 of IEEE-802.3. A 16-bit shift register receives serial data applied to the MDIO pin at
the rising-edge of the MDC clock signal. Once the preamble is received, the station management control
logic looks for the start-of-frame sequence and a read or write op-code, followed by the PHYAD and
REGAD fields. The default address for the 78Q2123/78Q2133 is 1. For a read operation, the MDIO port
becomes enabled as an output and the register data is loaded into a shift register for transmission. The
78Q2123/78Q2133 can work with a one-bit preamble rather than the 32 bits prescribed by IEEE-802.3.
This allows for faster programming of the registers. If a register does not exist at an address indicated by
the REGAD field or if the PHYAD field does not match the 78Q2123/78Q2133 PHYAD, a read of the
MDIO port will return all ones. For a write operation, the data is shifted in and loaded into the appropriate
register after the sixteenth data bit has been received. Writes to registers not supported by the
78Q2123/78Q2133 are ignored.
When the PHYAD field is all zeros, the Station Management Entity (STA) is requesting a broadcast data
transaction. All PHYs sharing the same Management Interface must respond to this broadcast request.
The 78Q2123/78Q2133 will respond to the broadcast data transaction.
9
78Q2123/78Q2133 Data Sheet DS_21x3_001
1.6
AdditionalFeatures
1.6.1 LED Indicators
There are two LED pins that can be used to indicate various states of operation of the
78Q2123/78Q2133. The function of these pins is programmable via the MR23 register as shown in the
table below:
LEDState Indication
0 1 = Link OK (Default LED0)
1 1 = RX or TX Activity (Default LED1)
2 1 = TX Activity
3 1 = RX Activity
4 1 = Collision
5 1 = 100 BASE-TX mode
6 1 = 10 BASE-T mode
7 1 = Full Duplex
8 1= Link OK & Blink = RX or TX Activity
The default status of these LEDs are “Link OK” for LED0 and “RX or TX Activity for LED1.
1.6.2 Interrupt Pin
The 78Q2123 and 78Q2133 have an Interrupt pin (INTR) that is asserted whenever any of the eight
interrupt bits of MR17.7:0 are set. These interrupt bits can be disabled via the MR17.15:8 Interrupt
Enable bits. The Interrupt Polarity bit, MR16.14, controls the active level of the INTR pin. When the INTR
pin is not asserted, the pin is held in a high impedance state. An external pull-up or pull-down resistor may
be required for use with the INTR pin.
1.6.3 Automatic MDI/ MDI-X Configuration
The 78Q2123 and 78Q2133 implement the automatic MDI/MDI-X configuration detailed in IEEE-802.3
2002. This function eliminates the need for cross over cables when connecting to another device. When
auto-switching is enabled, the 78Q2123/78Q2133 will attempt to detect activity on its given configuration.
If no activity is seen for 60 ms, the device will switch to the other configuration depending on a random
number sequence. The initial seed of the random number generator can be set via MR24.3:0. In
addition, the part includes an asynchronous MDIX reset that varies from 1.29 seconds to 1.57 seconds to
ensure lock step will not occur between two devices.
The 78Q2123 and 78Q2133 will also allow for auto-switching while the part is not in auto-negotiation
mode. The IEEE 802.3 specification will not work in this case if the other device is in auto-negotiation
mode. The 78Q2123 and 78Q2133 default to auto MDIX enabled with parallel detection. Register bits
MR24.6 and MR24.7 are both defaulted to 1. The 78Q2123 and 78Q2133 will resolve the proper
configuration within 5 seconds.
10
DS_21x3_001 78Q2123/78Q2133 Data Sheet
2 Pin Description
2.1
Legend
Type Description Type Description
A Analog Pin CI TTL-level Input
CIU TTL-level Input with Pull-up CIO TTL-compatible Bi-directional Pin
CIS TTL-level Input with Schmitt Trigger COZ Tristate-able CMOS Output
CO CMOS Output
S Supply G Ground
2.2
MII(MediaIndependentInterface)
Signal Pin Type Description
TX_CLK 15 COZ TRANSMIT CLOCK: TX_CLK is a continuous clock, which provides a
timing reference for the TX_EN, TX_ER and TXD[3:0] signals from the
MAC. The clock frequency is 25 MHz in 100BASE-TX mode and 2.5 MHz
in 10BASE-T mode. This pin is tri-stated in isolate mode and the TXHIM
mode.
TX_EN 16 CI TRANSMIT ENABLE: TX_EN is asserted by the MAC to indicate that
valid data for transmission is present on the TXD[3:0] pins.
TXD[3:0] [20:17] CI TRANSMIT DATA: TXD[3:0] receives data from the MAC for transmission
on a nibble basis. This data is captured on the rising edge of TX_CLK
when TX_EN is high.
TX_ER 14 CI TRANSMIT ERROR: TX_ER is asserted high by the MAC to request that
an error code-group be transmitted when TX_EN is high. In PCS bypass
mode, this pin becomes the MSB of the transmit 5-bit code group.
CRS 22 COZ CARRIER SENSE: When the 78Q2123/78Q2133 are not in repeater
mode, CRS is high whenever a non-idle condition exists on either the
transmitter or the receiver. In repeater mode, CRS is only active when a
non-idle condition exists on the receiver. This pin is tri-stated in isolate
mode.
COL 21 COZ COLLISION: COL is asserted high when a collision has been detected on
the media. In 10BASE-T mode COL is also used for the SQE test function.
This pin is tri-stated in isolate mode. During half duplex operation, the
rising edge of COL will occasionally occur upon the rising edge of
TX_CLK.
RX_CLK 12 COZ RECEIVE CLOCK: RX_CLK is a continuous clock, which provides a
timing reference to the MAC for the RX_DV, RX_ER and RXD[3:0] signals.
The clock frequency is 25 MHz in 100BASE-TX mode and 2.5 MHz in
10BASE-T mode. To reduce power consumption in 100BASE-TX mode,
the 78Q2123/78Q2133 provide an optional mode, enabled through
MR16.0, in which RX_CLK is held inactive (low) when no receive data is
detected. This pin is tri-stated in isolate mode.
RX_DV 11 COZ RECEIVE DATA VALID: RX_DV is asserted high to indicate that valid
data is present on the RXD[3:0] pins. In 100BASE-TX mode, it transitions
high with the first nibble of the preamble and is pulled low when the last
data nibble has been received. In 10BASE-T mode it transitions high when
the start-of-frame delimiter (SFD) is detected. This pin is tri-stated in
isolate mode.
11
78Q2123/78Q2133 Data Sheet DS_21x3_001
RXD[3:0] [5:8] COZ RECEIVE DATA: Received data is provided to the MAC via RXD[3:0].
These pins are tri-stated in isolate mode.
RX_ER 13 COZ RECEIVE ERROR: RX_ER is asserted high when an error is detected
during frame reception. In PCS bypass mode, this pin becomes the MSB of
the receive 5-bit code group. This pin is tri-stated in isolate mode.
MDC 2 CIS MANAGEMENT DATA CLOCK: MDC is the clock used for transferring
data via the MDIO pin.
MDIO 1 CIO MANAGEMENT DATA INPUT/OUTPUT: MDIO is a bi-directional port
used to access management registers within the 78Q2123/78Q2133. This
pin requires an external pull-up resistor as specified in IEEE-802.3.
2.3
Control and Status
Signal Pin Type Description
RST 23 CIS ACTIVE LOW RESET: When pulled low the pin resets the chip. The reset
pulse must be long enough to guarantee stabilization of the supply
voltage and startup of the oscillator. Refer to the Electrical Specifications
for the reset pulse requirements. There are two other ways to reset the
chip:
1. Through the internal power-on-reset (activated when the chip is
being powered up).
2. Through the MII register bit (MR 0.15).
INTR 32 COZ INTERRUPT PIN: This pin is used to signal an interrupt to the media
access controller. The pin is held in the high impedance state when an
interrupt is not indicated. The pin will be forced high or low to signal an
interrupt depending upon the value of the INPOL bit (MR16.14). The
events which trigger an interrupt can be programmed via the Interrupt
Control Register located at address MR17.
2.4
MDI(MediaDependent Interface)
Signal Pin Type Description
TXOP,
TXON
30,31 A TRANSMIT OUTPUT POSITIVE/NEGATIVE: Transmitter differential
outputs for both 10base-T and 100base-TX.
RXIP,
RXIN
28,27 A RECEIVE INPUT POSITIVE/NEGATIVE: Receiver differential inputs for
both 10BASE-T and 100BASE-TX.
2.5
Oscillator/Clock
Signal Pin Type Description
XTLP 24 A CRYSTAL INPUT: Should be connected to a 25 MHz crystal. If an
externally generated TTL compatibility clock signal is used, that signal is
applied here.
XTLN 25 A
CRYSTAL OUTPUT: Should be connected to a 25 MHz crystal. When an
external clock source is being used, this pin must be grounded.
2.6
Power Supply andGround
Signal Pin Type Description
PW R 9, 26 S +3.3VDC SUPPLY
GND 10, 29 G GROUND
12
DS_21x3_001 78Q2123/78Q2133 Data Sheet
2.7
LEDSignals(ProgrammabilityIsSecondaryRequirement)
Signal Pin Type Description
LED0 4 CO PROGRAMMABLE LED. Active low. Default status: LINK OK. Active to
indicate link with far end PHY.
LED1 3 CO PROGRAMMABLE LED. Active low. Default status: RX or TX ACTIVITY.
Active to indicate TX or RX activity on the MDI.
Other LED options selectable via MR23:
TRANSMIT: ON when there is a transmission (normally OFF).
RECEIVE: ON when there is a reception (normally OFF).
COLLISION: In half duplex mode, this is a collision indicator and turns-ON when
a collision occurs. In full duplex mode, this LED is held OFF.
BASE-TX: ON for 100BASE-TX connection and OFF for other
connections. LEDBTX is OFF during auto-negotiation.
BASE-T: ON for 10BASE-T connection and OFF for other connections.
LEDBT is OFF during auto-negotiation.
FULL DUPLEX: ON when in full duplex mode and OFF when in half
duplex mode.
LINK/ACT: ON for link, blink for activity.
13
78Q2123/78Q2133 Data Sheet DS_21x3_001
3 Register Description
The 78Q2123/78Q2133 implement 13 16-bit registers, which are accessible via the MDIO and MDC pins.
The supported registers are shown below in the following table. Attempts to read unsupported registers
will be ignored and the MDIO pin will not be enabled as an output, as per the IEEE 802.3 specification.
All of the registers except those that are unique to the 78Q2123/78Q2133 will respond to the broadcast
PHYAD value of ‘00000’. The registers specific to the 78Q2123/78Q2133 occupy address space
MR16-24.
Address Symbol Name Default (Hex)
0 MR0 Control (3100)
1 MR1 Status (7849)
2 MR2 PHY Identifier 1 000E
3 MR3 PHY Identifier 2 7237
4 MR4 Auto-Negotiation Advertisement (01E1)
5 MR5 Auto-Negotiation Link Partner Ability 0000
6 MR6 Auto-Negotiation Expansion 0000
7 MR7 Not Implemented 0000
8-14 MR8-14 Reserved 0000
15 MR15 Not Implemented 0000
16 MR16 Vendor Specific (0140)
17 MR17 Interrupt Control/Status Register 0000
18 MR18 Diagnostic Register 0000
19 MR19 Transceiver Control 4XXX
20-22 MR20-22 Reserved 0000
23 MR23 LED Configuration Register 0010
24 MR24 MDI/MDIX Control Register (00C0)
Legend
Type Description Type Description
R Readable by management. W Writeable by management.
WC Writeable by management. Self
Clearing.
RC Readable by management.
Cleared upon a read operation.
0/1 Default value upon power up or
reset.
14
DS_21x3_001 78Q2123/78Q2133 Data Sheet
3.1
MR0:ControlRegister
Bit Symbol Type Default Description
0.15 RESET R/WC 0 Reset: Setting this bit to ‘1’ resets the device and sets all
registers to their default states. This bit is self-clearing.
0.14 LOOPBK R/W 0 Loopback: When this bit is set to ‘1’, input data at TXD[3:0] is
output at RXD[3:0]. No transmission of data on the network
medium occurs and receive data on the network medium is
ignored. By default, the loopback signal path encompasses
most of the digital functional blocks. This bit allows for
diagnostic testing.
0.13 SPEEDSL R/W 1 Speed Selection: This bit determines the speed of operation
of the 78Q2123/78Q2133. Setting this bit to ‘1’ indicates
100Base-TX operation and a ‘0’ indicates 10Base-T mode.
This bit will default to a ‘1’ upon reset. When auto-negotiation
is enabled, this bit will not be writable and will have no effect
on the 78Q2123/78Q2133. If auto-negotiation is not enabled,
this bit may be written to force manual configuration.
0.12 ANEGEN R/W 1 Auto-Negotiation Enable: The auto-negotiation process is
enabled by setting this bit to ‘1’. This bit will default to ‘1’. If
this bit is cleared to ‘0’, manual speed and duplex mode
selection is accomplished through bits 0.13 (SPEEDSL) and
0.8 (DUPLEX) of the Control Register.
0.11 PWRDN R/W 0 Power-Down: The device may be placed in a low power
consumption state by setting this bit to ‘1’. While in the power-
down state, the device will still respond to management
transactions.
0.10 ISO R/W 0 Isolate: When set to ‘1’, the device will present a high-
impedance on its MII output pins. This allows for multiple
PHY’s to be attached to the same MII interface. When the
device is isolated, it still responds to management
transactions.
0.9 RANEG R/WC 0 Restart Auto-Negotiation: Normally, the Auto-Negotiation
process is started at power up. The process can be restarted
by setting this bit to ‘1’. This bit is self-clearing.
0.8 DUPLEX R/W 1 Duplex Mode: This bit determines whether the device
supports full- duplex or half-duplex. A ‘1’ indicates full-duplex
operation and a ‘0’ indicates half-duplex. This bit will default
to ‘1’ upon reset. When auto-negotiation is enabled, this bit
will not be writable and will have no effect on the
78Q2123/78Q2133. If auto-negotiation is not enabled, this bit
may be written to force manual configuration.
0.7 COLT R/W 0 Collision Test: When this bit is set to ‘1’, the device will assert
the COL signal in response to the assertion of the TX_EN
signal. Collision test is disabled if the PCSBP bit, MR16.1, is
high. Collision test can be activated regardless of the duplex
mode of operation.
0.6:0 RSVD R 0 Reserved
15
78Q2123/78Q2133 Data Sheet DS_21x3_001
3.2
MR1:StatusRegister
Bits 1.15 through 1.11 reflect the ability of the 78Q2123/78Q2133. They do not reflect any ability changes
made via the MII Management Interface to bits 0.13 (SPEEDSL) , 0.12 (ANEGEN) and 0.8 (DUPLEX)in
the Control Register.
Bit Symbol Type Default Description
1.15 100T4 R 0
100BASE-T4 Ability: Reads ‘0’ to indicate the
78Q2123/78Q2133 do not support 100Base-T4 mode.
1.14 100X_F R 1 100BASE-TX Full Duplex Ability:
0 : Not able
1 : Able
1.13 100X_H R 1 100BASE-TX Half Duplex Ability:
0 : Not able
1 : Able
1.12 10T_F R 1 10BASE-T Full Duplex Ability:
0 : Not able
1 : Able
1.11 10T_H R 1 10BASE-T Half Duplex Ability:
0 : Not able
1 : Able
1.10 100T2_F R 0
100BASE-T2 Full Duplex Ability: Reads ‘0’ to indicate the
78Q2123/78Q2133 do not support 100Base-T2 full duplex
mode.
1.9 100T2_H R 0
100BASE-T2 Half Duplex Ability: Reads ‘0’ to indicate the
78Q2123/78Q2133 do not support 100Base-T2 full duplex
mode.
1.8 EXTS R 0 Extended Status Information Availability: Reads 0’ to indicate
the 78Q2123/78Q2133 do not support Extended Status
information on MR15.
1.7 RSVD R 0 Reserved
1.6 MFPS R 0 Management Frame Preamble Suppression Support: A “0”
indicates that the 78Q2123/78Q2133 can read management
frames with a preamble.
1.5 ANEGC R 0 Auto-Negotiation Complete: A logic one indicates that the
Auto-Negotiation process has been completed, and that the
contents of registers MR4,5,6 are valid.
1.4 RFAULT RC 0 Remote Fault: A logic one indicates that a remote fault
condition has been detected and it remains set until it is
cleared. This bit can only be cleared by reading this register
(MR1) via the management interface.
1.3 ANEGA R (1) Auto-Negotiation Ability: When set, this bit indicates the
device’s ability to perform Auto-Negotiation. The value of this
bit is determined by the ANEGENbit (MR0.12).
1.2 LINK R 0 Link Status: A logic one indicates that a valid link has been
established. If the link status should transition from an OK
status to a NOT-OK status, this bit will become cleared and
remains cleared until it is read.
1.1 JAB RC 0 Jabber Detect: In 10Base-T mode, this bit is set during a
jabber event. After a jabber event, the bit remains set until
16
DS_21x3_001 78Q2123/78Q2133 Data Sheet
cleared by a read operation.
1.0 EXTD R 1 Extended Capability: Reads ’1’ to indicate the
78Q2123/78Q2133 provide an extended register set (MR2
and beyond).
3.3
MR2:PH Y Ide nt ifi er Re gis ter 1
Bit Symbol Type Value Description
2.15:0 OUI [23:6] R 000Eh Organizationally Unique Identifier: This value is 00-C0-39 for
Teridian Semiconductor Corporation. This register contains the
first 16-bits of the identifier.
3.4
MR3:PH Y Ide nt ifi er Re gis ter 2
Bit Symbol Type Value Description
3.15:10 OUI [5:0] R 1Ch Organizationally Unique Identifier: Remaining 6 bits of the
OUI.
3.9:4 MN R 23h Model Number: The last 2 digits of the model number
78Q2123 are encoded into the 6 bits for both 78Q2123 and
78Q2133.
3.3:0 RN R 07h Revision Number: The value ‘0111 corresponds to the
seventh revision of the silicon.
3.5
MR4:Auto-NegotiationAdvertisementRegister
Bit Symbol Type Default Description
4.15 NP R 0 Next Page: Not supported. Reads logic zero.
4.14 RSVD R 0 Reserved
4.13 RF R/W 0 Remote Fault: Setting this bit to 1’ allows the device to
indicate to the link partner a Remote Fault Condition.
4.12 A7 R 0 Reserved.
4.11 A6 R/W 0 Asymmetric PAUSE Support Indication for Full Duplex Links.
Default is 0 indicating not supported. If the MAC supports
Asymmetric PAUSE, this bit can be written as 1. Writing to this
register has no effect until auto-negotiation is re-initiated.
4.10 A5 R 0
PAUSE Support Indication for Full Duplex Links. Default is 0
indicating not supported. If the MAC supports PAUSE, this bit
can be written as 1. Writing to this register has no effect until
auto-negotiation is re-initiated
4.9 A4 R 0 100BASE-T4: The 78Q2123/78Q2133 do not support
100BASE-T4 operation.
4.8 A3 R/W (1) 100BASE-TX Full Duplex: If the MR1.14 bit is ‘1’, this bit will
be set to ‘1’ upon reset and will be writeable. Otherwise, this
bit cannot be set to ‘1’ by the management.
4.7 A2 R/W (1) 100BASE-TX: If the MR1.13 bit is ‘1’, this bit will be set to ‘1’
upon reset and will be writeable. Otherwise, this bit cannot be
set to ‘1’ by the management.
4.6 A1 R/W (1) 10BASE-T Full Duplex: If the MR1.12 bit is ‘1’, this bit will be
set to ‘1’ upon reset and will be writeable. Otherwise, this bit
cannot be set to 1’ by the management.
17
78Q2123/78Q2133 Data Sheet DS_21x3_001
4.5 A0 R/W (1) 10BASE-T: If the MR1.11 bit is ‘1’, this bit will be set to ‘1’
upon reset and will be writeable. Otherwise, this bit cannot be
set to ‘1’ by the management.
4.4:0 S4:0 R 01h Selector Field: Hard coded with the value of ‘00001’ for IEEE
802.3.
Note: Technology Ability Field: MR4.12:5 are the Technology Ability Field bits (A7:0). The default value
of this field is dependent upon the MR1.15:11 register bits. This field can be overwritten by management
to auto-negotiate to an alternate common technology. Writing to this register has no effect until
auto-negotiation is re-initiated.
3.6
MR5: Auto-Negotiation Link Partner Ability Register
Bit Symbol Type Default Description
5.15 NP R 0 Next Page: When ‘1’ is read, it indicates the link partner
wishes to engage in Next Page exchange.
5.14 ACK R 0
Acknowledge: When ‘1’ is read, it indicates the link partner has
successfully received at least 3 consecutive and consistent
FLP bursts.
5.13 RF R 0 Remote Fault: When 1’ is read, it indicates the link partner has
a fault.
5.12:5 A7:0 R 0 Technology Ability Field: This field contains the technology
ability of the link partner. The bit definition is the same as
MR4.12:5.
5.4:0 S4:0 R 00h Selector Field: This field contains the type of message sent by
the link partner. For an IEEE 802.3 compliant link partner, this
field should be ‘00001’.
3.7
MR6:Auto-NegotiationExpansionRegister
Bit Symbol Type Default Description
6.15:5 RSVD R 0 Reserved
6.4 PDF RC 0 Parallel Detection Fault: When ‘1’ is read, it indicates that
more than one technology has been detected during link up.
This bit is cleared when read.
6.3 LPNPA R 0
Link Partner Next Page Able: When ‘1’ is read, it indicates the
link partner supports the Next Page function.
6.2 NPA R 0 Next Page Able: Reads ‘0’ since the 78Q2123/78Q2133 do not
support Next Page function.
6.1 PRX RC 0 Page Received: Reads ‘1’ when a new link code word has
been received into the Auto-Negotiation Link Partner Ability
Register. This bit is cleared upon read.
6.0 LPANEGA R 0 Link Partner Auto-Negotiation Able: When ‘1’ is read, it
indicates the link partner is able to participate in the Auto-
Negotiation function.
3.8
MR16:Vendor SpecificRegister
Bit Symbol Type Default Description
16.15 RPTR R/W (0) Repeater Mode: When set, the 78Q2123/78Q2133 are put
into Repeater mode of operation. In this mode, full duplex is
18
DS_21x3_001 78Q2123/78Q2133 Data Sheet
prohibited, CRS responds to receive activity only and, in
10Base-T mode, the SQE test function is disabled.
16.14 INPOL R/W 0 When this bit is ‘0’, the INTR pin is forced low to signal an
interrupt. Setting this bit to 1’ causes the INTR pin to be
forced high to signal an interrupt.
16.13 RSVD R 0 Reserved
16.12 TXHIM R/W 0 Transmitter High-Impedance Mode: When set, the
TXOP/TXON transmit pins and the TX_CLK pin are put into a
high-impedance state. The receive circuitry remains fully
functional.
16.11 SQEI R/W 0 SQE Test Inhibit: Setting this bit to ‘1’ disables 10Base-T
SQE testing. By default, this bit is ‘0’ and the SQE test is
performed by generating a COL pulse following the
completion of a packet transmission.
16.10 NL10 R/W 0 10Base-T Natural Loopback: Setting this bit to 1’ causes
transmit data received on the TXD0-3 pins to be automatically
looped back to the RXD0-3 pins when 10Base-T mode is
enabled.
16.9 RSVD R 0 Reserved
16.8 RSVD R 1 Reserved
16.7 RSVD R 0 Reserved
16.6 RSVD R 1 Reserved
16.5 APOL R/W 0 Auto Polarity: During auto-negotiation and 10BASE-T mode,
the 78Q2123/78Q2133 are able to automatically invert the
received signal due to a wrong polarity connection. It does so
by detecting the polarity of the link pulses. Setting this bit to
‘1’ disables this feature.
16.4 RVSPOL R/W 0 Reverse Polarity: The reverse polarity is detected either
through 8 inverted 10Base-T link pulses (NLP) or through one
burst of inverted clock pulses in the auto-negotiation link
pulses (FLP). When the reverse polarity is detected and if the
Auto Polarity feature is enabled, the 78Q2123/78Q2133 will
invert the receive data input and set this bit to ‘1’. If Auto
Polarity is disabled, then this bit is writeable. Writing a ‘1’ to
this bit forces the polarity of the receive signal to be reversed.
16.3:2 RSVD R/W 0h Reserved: Must set to ‘00’.
16.1 PCSBP R/W 0 PCS Bypass Mode: When set, the 100Base-TX PCS and
scrambling/ descrambling functions are bypassed. Scrambled
5-bit code groups for transmission are applied to the TX_ER,
TXD3-0 pins and received on the RX_ER, RXD3-0 pins. The
RX_DV and TX_EN signals are not valid in this mode.
PCSBP mode is valid only when 100Base-TX mode is
enabled and auto-negotiation is disabled.
16.0 RXCC R/W 0 Receive Clock Control: This function is valid only in 100Base-
TX mode. When set to ‘1’, the RX_CLK signal will be held low
when there is no data being received (to save power). The
RX_CLK signal will restart 1 clock cycle before the assertion
of RX_DV and will be shut off 64 clock cycles after RX_DV
goes low. RXCC is disabled when loopback mode is enabled
(MR0.14 is high). This bit should be kept at logic zero when
PCS Bypass mode is used.
19
78Q2123/78Q2133 Data Sheet DS_21x3_001
3.9
MR17:InterruptControl/StatusRegister
The Interrupt Control/Status Register provides the means for controlling and observing the events, which
trigger an interrupt on the INTR pin. This register can also be used in a polling mode via the MII Serial
Interface as a means to observe key events within the PHY via one register address. Bits 0 through 7 are
status bits, which are each set to logic one based upon an event. These bits are cleared after the register
is read. Bits 8 through 15 of this register, when set to logic one, enable their corresponding bit in the
lower byte to signal an interrupt on the INTR pin. The assertion level of this interrupt signal output on the
INTR pin can be set via the MR16.14 (INPOL) bit.
Bit Symbol Type Default Description
17.15 JABBER_IE R/W 0 Jabber Interrupt Enable
17.14 RXER_IE R/W 0 Receive Error Interrupt Enable
17.13 PRX_IE R/W 0 Page Received Interrupt Enable
17.12 PDF_IE R/W 0 Parallel Detect Fault Interrupt Enable
17.11 LP-ACK_IE R/W 0 Link Partner Acknowledge Interrupt Enable
17.10 LS-CHG_IE R/W 0 Link Status Change Interrupt Enable
17.9 RFAULT_IE R/W 0 Remote Fault Interrupt Enable
17.8 ANEG-
COMP_IE
R/W 0 Auto-Negotiation Complete Interrupt Enable
17.7 JAB_INT RC 0 Jabber Interrupt: This bit is set high when a Jabber
event is detected by the 10Base-T circuitry.
17.6 RXER_INT RC 0 Receive Error Interrupt: This bit is set high when the
RX_ER signal transitions high.
17.5 PRX_INT RC 0 Page Received Interrupt: This bit is set high when a new
page has been received from the link partner during
auto-negotiation.
17.4 PDF_INT RC 0 Parallel Detect Fault Interrupt: This bit is set high by the
auto-negotiation logic when a parallel detect fault
condition is indicated.
17.3 LP-ACK_INT RC 0 Link Partner Acknowledge Interrupt: This bit is set high
by the auto-negotiation logic when FLP bursts are
received with the acknowledge bit set.
17.2 LS-CHG_INT RC 0 Link Status Change Interrupt: This bit is set when the
link transitions from an OK status to a FAIL status.
17.1 RFAULT_INT RC 0 Remote Fault Interrupt: This bit is set when a remote
fault condition has been indicated by the link partner.
17.0 ANEG-
COMP_INT
RC 0 Auto-Negotiation Complete Interrupt: This bit is set by
the auto-negotiation logic upon successful completion of
auto-negotiation.
20
DS_21x3_001 78Q2123/78Q2133 Data Sheet
3.10
MR18:DiagnosticRegister
Bit Symbol Type Default Description
18.15:13 RSVD R 0 Reserved
18.12 ANEGF RC 0 Auto-Negotiation Fail Indication: This bit is set when
auto-negotiation completes and no common technology was
found. It remains set until read.
18.11 DPLX R 0
Duplex Indication: This bit indicates the result of the
auto-negotiation for duplex arbitration as follows:
0 = Half-duplex was the highest common denominator
1 = Full-duplex was the highest common denominator
18.10 RATE R 0
Rate Indication: This bit indicates the result of the auto-
negotiation for data rate arbitration as follows:
0 = 10Base-T was the highest common denominator
1 = 100Base-TX was the highest common denominator
18.9 RXSD R 0 Receiver Signal Detect Indication: In 10Base-T mode, this
bit indicates that Manchester data has been detected. In
100Base-TX mode, it indicates that the receive signal
activity has been detected (but not necessarily locked on
to).
18.8 RX_LOCK R 0 Receive PLL Lock Indication: Indicates that the Receive
PLL has locked onto the receive signal for the selected
speed of operation (10Base-T or 100Base-TX).
18.7:0 RSVD R 00h Reserved: Must set to ‘00h’.
3.11
MR19: Transceiver Control
Bit Symbol Type Default Description
19.15:14 TXO[1:0] R/W 01 Transmit Amplitude Selection: Sets the transmit output
amplitude to account for transmit transformer insertion loss.
00 = Gain set for 0.0dB of insertion loss.
01 = Gain set for 0.4dB of insertion loss.
10 = Gain set for 0.8dB of insertion loss.
11 = Gain set for 1.2dB of insertion loss.
19.13:0 RSVD R XXXh Reserved
3.12
MR20:Reserved
Bit Symbol Type Default Description
20.15:0 Reserved NA XXXXh Reserved: must be 0000h.
3.13
MR21:Reserved
Bit Symbol Type Default Description
21.15:0 Reserved NA XXXXh Reserved: must be 0000h.
3.14
MR22:Reserved
Bit Symbol Type Default Description
22.15:0 Reserved NA XXXXh Reserved: must be 0000h.
21
78Q2123/78Q2133 Data Sheet DS_21x3_001
3.15
MR23:LEDConfigurationRegister
Bit Symbol Type Default Description
23.15:8 Reserved NA <0000> Must set to zero on each write to MR23
23.7:4 LED1[3:0] R/W <1h> 0000 = Link OK
0001 = RX or TX Activity (Default LED1)
0010 = TX Activity
0011 = RX Activity
0100 = Collision
0101 = 100 BASE-TX mode
0110 = 10 BASE-T mode
0111 = Full Duplex
1000 = Link OK/Blink=RX or TX Activity
23.3:0 LED0[3:0] R/W <0h> 0000 = Link OK (Default LED0)
0001 = RX or TX Activity
0010 = TX Activity
0011 = RX Activity
0100 = Collision
0101 = 100 BASE-TX mode
0110 = 10 BASE-T mode
0111 = Full Duplex
1000 = Link OK/Blink=RX or TX Activity
3.16
MR24:MDI/MDIXControlRegister
Bit Symbol Type Default Description
24.15:8 Reserved R 0 Reserved
24.7 PD_MODE R/W 1 Write a ‘1’ to this bit to add Parallel Detect mode. This
will allow auto-switching to work when auto-negotiation is
off while the other device has it on.
24.6 AUTO_SW R/W 1 Write a ‘1’ to this bit to enable auto switching.
24.5 MDIX R/W 0 Indicates state of the MDI pair or force configuration:
1 = MDIX (cross over)
0 = MDI
When auto_sw is a ‘1’, this bit will only be readable.
When auto_sw is a ‘0’ this bit can be written to set the
configuration.
24.4 MDIX_CM R 0 Indicates completion of auto-switch sequence.
1 = Sequence completed.
0 = Sequence in progress or auto-switch is disabled.
24.3:0 MDIX_SD R/W <0000> Write initial pattern seed for switching algorithm. The
initial seed directly affects attempts [5,4] respectively to
write bits [3:0]. Setting to [0000] will result in device
using its own seed of [0101].
22
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4 Electrical Specifications
4.1
AbsoluteMaximumRatings
Operation above maximum rating may permanently damage the device.
Parameter Rating
DC Supply Voltage (Vcc) -0.5 to 4.0 VDC
Storage Temperature -65 to 150 qC
Pin Voltage (except TXOP/N) -0.3 to (Vcc+0.6) VDC
Pin Voltage (TXOP/N only) -0.3 to (Vcc+1.4) VDC
Pin Current r120 mA
4.2
RecommendedOperatingConditions
Unless otherwise noted, all specifications are valid over these temperatures and supply voltage ranges.
Parameter Rating
DC Voltage Supply (Vcc) 3.3 r0.3 VDC
78Q2123 Ambient Operating Temperature (Ta) 0 to 70 qC
78Q2133 Ambient Operating Temperature (Ta) -40 to 85 qC
Maximum Junction Temperature 125 qC
Package Thermal Conductivity (Tja) 50 qC/W
4.3
DCCharacteristics
Parameter Symbol Conditions Min Nom Max Unit
Supply Current
I
CC
Vcc = 3.3V;
Auto-Negotiation
10BT (Idle)
10BT (Normal Activity)
100BTX
48
26
88
88
56
35
110
110
mA
Supply Current
I
CC
Power-down mode 6 mA
23
78Q2123/78Q2133 Data Sheet DS_21x3_001
4.4
DigitalI/OCharacteristics
Pi ns of ty pe CI, CIU, CID, CIO
Parameter Symbol Conditions Min Nom Max Unit
Input Voltage Low Vil
0.8 V
Input Voltage High Vih 2.0 3.6 V
Input Current Iil, Iih -1 1 PA
Pull-up Resistance Rpu Type CIU only 38 56 78 k:
Input Capacitance Cin
8 pF
Pi ns of type CI S
Parameter Symbol Conditions Min Nom Max Unit
Low-to-High Threshold Vt+
2.0 V
High-to-Low Threshold Vt- 0.8 V
Input Current Iil, Iih -1 1 PA
Input Capacitance Cin
8 pF
Input Hysteresis Vhy 125 mV
Pi ns of type CO Z
Parameter Symbol Conditions Min Nom Max Unit
Output Voltage Low Vol Iol = 4mA 0.4 V
Output Voltage High Voh Ioh = -4mA 2.4 V
Output Transition Time Tt CL = 20pF 6 ns
Tristate Output
Leakage Current
Iz -1 1 PA
Pi ns of ty pe CO
Parameter Symbol Conditions Min Nom Max Unit
Output Voltage Low Vol Iol = 4mA 0.4 V
Output Voltage High Voh Ioh = -4mA 2.4 V
Output Transition Time Tt CL = 20pF 6 ns
Pi ns of ty pe CIO
Parameter Symbol Conditions Min Nom Max Unit
Output Voltage Low Vol Iol = 4mA 0.4 V
Output Voltage High Voh Ioh = -4mA 2.4 V
Output Transition Time Tt CL = 20pF 6 ns
24
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4.5
DigitalTimingCharacteristics
4.5.1 RST Characteristics
Figure 1: RST Pulse Duration
Parameter Symbol Conditions Min Nom Max Unit
RST Pulse Assertion Treset VCC = 3.3V and
oscillator stabilized
30 Oscillator
Clock
Cycles
4.5.2 MII Transmit Interface
Characteristics Symbol Conditions Min Nom Max Unit
Setup Time: TX_CLK to
TXD[3:0], TX_EN, TX_ER
TXSU 15 ns
Hold Time: TX_CLK to
TXD[3:0], TX_EN, TX_ER
TXHD 0 ns
CKIN-to-TX_CLK Delay TCKIN 0 40 ns
TX_CLK Duty-Cycle 40 60 %
Figure 2: Transmit Inputs to the 78Q2123/78Q2133
VCC
Oscillator
RST
Treset
25
78Q2123/78Q2133 Data Sheet DS_21x3_001
4.5.3 MII Receive Interface
Characteristics Symbol Conditions Min Nom Max Unit
Receive Output Delay:
RX_CLK to RXD[3:0],
RX_DV, RX_ER
RXDLY 10 30 ns
RX_CLK Duty-Cycle 40 60 %
Figure 3: Receive Outputs from the 78Q2123/78Q2133
4.6
MDIO Interface Input Timing
Characteristics Symbol Conditions Min Nom Max Unit
Setup Time: MDC to MDIO MIOSU 10 ns
Hold Time: MDC to MDIO MIOHD 10 ns
Max Frequency: MDC Fmax
25 MHz
Figure 4: MDIO as an Input to the 78Q2123/78Q2133
26
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4.6.1 MDIO Interface Output Timing
Characteristics Symbol Conditions Min Nom Max Unit
MDC to MDIO data delay MC2D
30 ns
MDIO output from high Z
to driven after MDC
MCZ2D
30 ns
MDIO output from driven
to high Z after MDC
MCD2Z
30 ns
Figure 5: MDIO as an Output to the 78Q2123/78Q2133
27
78Q2123/78Q2133 Data Sheet DS_21x3_001
4.6.2 MDIO Interface Output Timing
Figure 6: MDIO Interface Output Timing
28
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4.6.3 100BASE-TX System Timing
System timing requirements for 100BASE-TX operation are listed in Table 24-2 of Clause 24 of IEEE
802.3.
Parameter Condition Nom Unit
TX_EN Sampled to first bit of “J” on MDI
output
12 BT
First bit of “J” on MDI input to CRS assert 16 BT
First bit of “T” on MDI input to CRS
de-assert
23 BT
First bit of “J” on MDI input to COL assert 20 BT
First bit of “T” on MDI input to COL
de-assert
24 BT
TX_EN Sampled to CRS assert RPTR = low 6 BT
TX_EN sampled to CRS de-assert RPTR = low 6 BT
4.6.4 10BASE-T System Timing
Parameter Condition Min Nom Max Unit
TX_EN (MII) to TD Delay
6 BT
RD to RXD at (MII) Delay
6 BT
Collision delay
9 BT
SQE test wait
1 Ps
SQE test duration
1 Ps
Jabber on-time* 20 150 ms
Jabber off-time* 250 750 ms
* Guarantee by design. The specifications in the following table are included for information only.
29
78Q2123/78Q2133 Data Sheet DS_21x3_001
4.7
AnalogElectricalCharacteristics
4.7.1 100BASE-TX Transmitter
Parameter Condition Min Nom Max Unit
Peak Output Amplitude
(|Vp+|, |Vp-|)
(see note below)
Best-fit over 14 bit times;
0.4 dB Transformer loss
950 1050 mVpk
Output Amplitude
Symmetry
|Vp +|
|Vp -|
0.98 1.02
Output Overshoot Percent of Vp+, Vp- 5 %
Rise/Fall time (tr, tf) 10-90% of Vp+, Vp- 3 5 ns
Rise/Fall time Imbalance |tr - tf| 500 ps
Duty Cycle Distortion Deviation from best-fit time-
grid;
010101... Sequence
r250 ps
Jitter Scrambled Idle 1.4 ns
Note: Measured at the line side of the transformer.
Test Condition: Transformer P/N: TLA-6T103
Line Termination: 100 :±1%
4.7.2 100BASE-TX Transmitter (Informative)
The specifications in the following table are included for information only. They are mainly a function of
the external transformer and termination resistors used for measurements.
Parameter Condition Min Max Unit
Return Loss 2 < f < 30 MHz
30 < f < 60 MHz
60 < f < 80 MHz
16
1620 log§f ·
¨¸
©30MHz¹
10
dB
Open-Circuit Inductance -8 < Iin < 8 mA 350 PH
4.7.3 100BASE-TX Receiver
Parameter Condition Min Nom Max Unit
Signal Detect Assertion
Threshold
500 600 700 mVppd
Signal Detect De-assertion
Threshold
275 350 425 mVppd
Differential Input Resistance
20 k:
Jitter Tolerance (pk-pk) Not tested in production 4 ns
Baseline Wander Tracking -75 +75 %
Signal Detect Assertion Time Not tested
1000 Ps
Signal Detect De-assertion
Time
Not tested 4 Ps
30
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4.7.4 10BASE-T Transmitter
The Manchester-encoded data pulses, the link pulse and the start-of-idle pulse are tested against the
templates and using the procedures found in Clause 14 of IEEE 802.3.
Parameter Condition Min Nom Max Unit
Peak Differential Output Signal
(see note below)
All data patterns 2.2 2.8 V
Harmonic Content
(dB below fundamental)
Any harmonic
All ones data
Not tested
27 dB
Link Pulse Width
100 ns
Start-of-Idle Pulse Width Last bit 0
Last bit 1
300
350
ns
ns
Note: Measured at the line side of the transformer.
Test Condition: Transformer P/N: TLA-6T103
Line Termination: 100:±1%
4.7.5 10BASE-T Transmitter (Informative)
The specifications in the following table are included for information only. They are mainly a function of
the external transformer and termination resistors used for measurements.
Parameter Condition Min Nom Max Unit
Output return loss 15 dB
Output Impedance Balance 1 MHz < freq < 20 MHz
29

17log
§
f
·
¨ ¸
©
10
¹
dB
Peak Common-mode Output
Voltage
50 mV
Common-mode rejection 15 Vpk, 10.1 MHz sine wave
applied to transmitter
common-mode. All data
sequences.
100 mV
Common-mode rejection jitter 15 Vpk, 10.1 MHz sine wave
applied to transmitter
common-mode. All data
sequences.
1ns
4.7.6 10BASE-T Receiver
Parameter Condition Min Nom Max Unit
DLL Phase Acquisition Time
10 BT
Jitter Tolerance (pk-pk) 30 ns
Input Squelched Threshold 500 600 700 mVppd
Input Unsquelched Threshold 275 350 425 mVppd
Differential Input Resistance
20 k:
Bit Error Ratio
10-10
Common-mode rejection Square wave
0 < f < 500 kHz
Not tested
25 V
31
CCD
DD
V
8
7
6
5
4
3
2
1
15
28
78Q2123/78Q2133 Data Sheet DS_21x3_001
R4
100
R5
100 VCC
R2
5.1K
LED 1 D1
LED 0 D2
VCC
R1
680
R3
680
VCC
INTR
C1
0.1uF
R8
49.9
R9
49.9
VCC
R6
R7
C5
C2
VCC
J1
MDIO
MDC
RXD3
RXD2
RXD1
RXD0
RXDV
R11
100
0.1uF
R10
100
9
10 V
11 GN
RX_D
78Q2123
78Q2133
33
PB_GND 32
INTR 31
TXON 30
TXOP
0.01uF
T1
1
2 TD+
TDCT
0.1uF
16
TX+ 15
TXCT
RJ45
8
7
6
RXCLK
RXER
TXER
TXCLK
TXEN
TXD0
TXD1 R12 R13
12 RX_CLK
13 RX_ER
14 TX_ER
16 TX_CLK
TX_EN
78Q2123
GND 29
RXIP 27
RXIN 26
VCC 25
XTLN
3
4 TD-
5 NC1
6 NC2
7 RD+
8 RDCT
RD-
14 5
TX- 13 4
NC4 12 3
NC3 11 2
RX+ 10 1
RXCT
9
RX-
TXD2
TXD3
COL
CRS
100 100
Y1
25.000MHz
TLA-6T118LF
VCC
R14
R15 C11 C12 R16 R17 R18 R19 R20 R21 C10
C13
C14 49.9 49.9
0.01UF 0.1UF
75 75 75 75 75 75 0.1uF
1.5kV
R22
100
R23
100
VCC
R24
10k
C15
0.1uF
27pF 27pF
C13 and C14 must be calibrated
in actual application board f or
25.000MHz +/-50ppm.
Figure 7: Application Diagram for 78Q2123/78Q2133
32
Rev. 1.6
17
18
19
20
21
22
23
24
TXD0
TXD1
TXD2
TXD3
COL
CRS
RST
XTLP
RXD0
RXD1
RXD2
RXD3
LED0
LED1
MDC
MDIO
10 9
DS_21x3_001 78Q2123/78Q2133 Data Sheet
4.8
Isolation Transformers
Two simple 1:1 isolation transformers are required at the line interface. Transformers with integrated
common-mode chokes are recommended for exceeding FCC requirements. This table gives the
recommended line transformer characteristics.
Name Value Condition
Turns Ratio 1 CT : 1 CT r5%
Open-Circuit Inductance 350 PH (min) @ 10 mV, 10 kHz
Leakage Inductance 0.40 PH (max) @ 1 MHz (min)
Inter-Winding Capacitance 25 pF (max)
D.C. Resistance 0.9 :(max)
Insertion Loss 0.4 dB (typ) 0 - 65 MHz
HIPOT 1500 Vrms
Note: The 100Base-TX amplitude specifications assume a transformer loss of 0.4 dB. For the transmit
line transformer with higher insertion losses, up to 1.2 dB of insertion loss can be compensated by
selecting the appropriate setting in the Transmit Amplitude Selection bits in register MR19.15:14.
4.9
ReferenceCrystal
If the internal crystal oscillator is to be used, a crystal with the following characteristics should be chosen.
Name Value Units
Frequency 25.00000 MHz
Load Capacitance* 4** pF
Frequency Tolerance r50 PPM
Aging r2 PPM/yr
Temperature Stability ( 0 - 70oC) r5 PPM
Oscillation Mode Parallel Resonance, Fundamental Mode
Parameters at 25oC r2oC ; Drive Level = 0.5 mW
Drive Level (typ) 50-100 PW
Shunt Capacitance (max) 10 pF
Motional Capacitance (min) 10 pF
Series Resistance (max) 60 :
Spurious Response (max) > 5 dB below main within 500 kHz
* Equivalent differential capacitance across the XTLP/XTLN pins.
** If crystal with a larger load is used, external shunt capacitors to ground should be added to make up
the equivalent capacitance difference.
33
78Q2123/78Q2133 Data Sheet DS_21x3_001
T
f
Tclkper
Tclkhi
Figure 8: External XTLP Oscillator Characteristics
4.9.1 External XTLP Oscillator Characteristics
Parameter Symbol Condition Min Nom Max Unit
XTLP Input Level See specification for
CIS-type input
XTLN Input Low
Voltage
0.8 V
XTLP Frequency f See Note 1 25.000 MHz
XTLP Period Tclkper See Note 1 40 ns
XTLP Duty Cycle Tclkhi / Tclkper 40 60 %
Rise / Fall Time Tr, Tf
4.0 ns
Absolute Jitter Input signaling
requirements = CIS
0.1 ns
Note 1: IEEE 802.3 frequency tolerance r50 ppm.
Tr
XTLP
34
DS_21x3_001 78Q2123/78Q2133 Data Sheet
5 Package Pin Designations
(Top View)
MDIO
MDC
LED1
LED0
RXD3
RXD2
RXD1
RXD0
XTLP
RST
CRS
COL
TXD3
TXD2
TXD1
TXD0
Note: For information only, actual package outline will vary depending on package type.
Figure 9: Package Pin Designations
1 24
2 23
3 22
4 TERIDIAN 21
78Q2123
5 20
78Q2133
6 19
7 18
8 17
PWR 932INTR
GND 10 31 TXON
RX_DV 11 30 TXOP
RX_CLK 12 29 GND
RX_ER 13 28 RXIP
TX_ER 14 27 RXIN
TX_CLK 15 26 PWR
16
TX_EN 25 XTLN
35
78Q2123/78Q2133 Data Sheet DS_21x3_001
6 Package Information
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
32-QFN G3255+3 21-0697 90-0434
32-TQFN T3255+4 21-0140 90-0012
7 Ordering Information
Part Package Option Ordering Number IC Marking
78Q2123,
Lead-Free,
Commercial
Temp
32-QFN
Bulk 78Q2123/F
Tape & Reel 78Q2123R/F
32-TQFN
Bulk 78Q2123S/F
Tape & Reel 78Q2123SR/F
78Q2133,
Lead-Free,
Industrial Temp
32-QFN Bulk 78Q2133/F
Tape & Reel 78Q2133R/F
32-TQFN
Bulk 78Q2133S/F
Tape & Reel 78Q2133SR/F
YY: Last two digits of year of assembly
WW: Week of assembly
RRRR:Die Rev Code from Reliability Database
###: Will be substituted with the last 3 numeric characters from the lot number
@@: Will be substituted with the first two alpha characters after the numeric characters from the lot
number
36
DS_21x3_001 78Q2123/78Q2133 Data Sheet
Revision History
Rev. # Date Comments
1.0 9/15/2005 First publication.
1.6 4/16/2010 Removed the 32-pin TQFP option.
2.0 9/24/2014 Added 32-TQFN package.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
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