SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
Members of the Texas Instruments
SCOPE
Family of Testability Products
D
Members of the Texas Instruments
Widebus
Family
D
Compatible With the IEEE Standard
1149.1-1990 (JTAG) Test Access Port and
Boundary-Scan Architecture
D
Include D-Type Flip-Flops and Control
Circuitry to Provide Multiplexed
Transmission of Stored and Real-Time Data
D
Bus Hold on Data Inputs Eliminates the
Need for External Pullup Resistors
D
B-Port Outputs of ’ABTH182646A Devices
Have Equivalent 25-Ω Series Resistors, So
No External Resistors Are Required
D
State-of-the-Art
EPIC-
ΙΙ
B
BiCMOS Design
D
One Boundary-Scan Cell Per I/O
Architecture Improves Scan Efficiency
D
SCOPE
Instruction Set
– IEEE Standard 1149.1-1990 Required
Instructions and Optional CLAMP and
HIGHZ
– Parallel-Signature Analysis at Inputs
– Pseudo-Random Pattern Generation
From Outputs
– Sample Inputs/Toggle Outputs
– Binary Count From Outputs
– Device Identification
– Even-Parity Opcodes
D
Packaged in 64-Pin Plastic Thin Quad Flat
(PM) Packages Using 0.5-mm
Center-to-Center Spacings and 68-Pin
Ceramic Quad Flat (HV) Packages Using
25-mil Center-to-Center Spacings
1B4
1B5
1B6
GND
1B7
1B8
1B9
VCC
NC
2B1
2B2
2B3
2B4
GND
2B5
2B6
2B7
1A3
1A4
1A5
GND
1A6
1A7
1A8
1A9
NC
VCC
2A1
2A2
2A3
GND
2A4
2A5
2A6
V
NC
TMS
1CLKBA
1A2
1A1
1OE
GND
1SAB
1CLKAB
TDO
NC
TCK
2CLKBA
2SBA
2A9
GND
2OE
2SAB
2CLKAB
TDI
2A7
2A8
1SBA
1DIR
GND
2DIR
2B9
2B8
GND
1B1
1B2
1B3
28 29
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
30
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26 31 32 33 34
87 65493168672
35 36 37 38 39
66 65
27
64 63 62 61
40 41 42 43
SN54ABTH18646A, SN54ABTH182646A . . . HV PACKAGE
(TOP VIEW)
CC
V
CC
NC – No internal connection
Copyright 1996, Texas Instruments Incorporated
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information current as of publication date. Products conform to
specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all
parameters.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SCOPE, Widebus, and EPIC-ΙΙB are trademarks of Texas Instruments Incorporated.
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
2A9
GND
2SAB
2CLKAB
2A7
2A8
2OE
TDI
2CLKBA
2SBA
2DIR
2B9
V
TCK
GND
2B8
CC
18 19
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
21 22 23 24
63 62 61 60 5964 58 56 55 5457
25 26 27 28 29
53 52
17
51 50 49
30 31 32
1OE
GND
1CLKAB
TDO
1A2
1A1
1SAB
V
1SBA
1DIR
1B1
1B2
TMS
1CLKBA
GND
1B3
1A3
1A4
1A5
GND
1A6
1A7
1A8
1A9
VCC
2A1
2A2
2A3
GND
2A4
2A5
2A6
1B4
1B5
1B6
GND
1B7
1B8
1B9
VCC
2B1
2B2
2B3
2B4
GND
2B5
2B6
2B7
CC
SN74ABTH18646A, SN74ABTH182646A . . . PM PACKAGE
(TOP VIEW)
description
The ’ABTH18646A and ’ABTH182646A scan test devices with 18-bit bus transceivers and registers are
members of the T exas Instruments SCOPE testability integrated-circuit family . This family of devices supports
IEEE Standard 1149.1-1990 boundary scan to facilitate testing of complex circuit-board assemblies. Scan
access to the test circuitry is accomplished via the 4-wire test access port (TAP) interface.
In the normal mode, these devices are 18-bit bus transceivers and registers that allow for multiplexed
transmission of data directly from the input bus or from the internal registers. They can be used either as two
9-bit transceivers or one 18-bit transceiver. The test circuitry can be activated by the TAP to take snapshot
samples of the data appearing at the device pins or to perform a self test on the boundary-test cells. Activating
the TAP in the normal mode does not affect the functional operation of the SCOPE bus transceivers and
registers.
Transceiver function is controlled by output-enable (OE) and direction (DIR) inputs. When OE is low, the
transceiver is active and operates in the A-to-B direction when DIR is high or in the B-to-A direction when DIR
is low. When OE is high, both the A and B outputs are in the high-impedance state, effectively isolating both
buses.
Data flow is controlled by clock (CLKAB and CLKBA) and select (SAB and SBA) inputs. Data on the A bus is
clocked into the associated registers on the low-to-high transition of CLKAB. When SAB is low, real-time A data
is selected for presentation to the B bus (transparent mode). When SAB is high, stored A data is selected for
presentation to the B bus (registered mode). The function of the CLKBA and SBA inputs mirrors that of CLKAB
and SAB, respectively. Figure 1 shows the four fundamental bus-management functions that are performed with
the ’ABTH18646A and ’ABTH182646A.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description (continued)
In the test mode, the normal operation of the SCOPE bus transceivers and registers is inhibited, and the test
circuitry is enabled to observe and control the I/O boundary of the device. When enabled, the test circuitry
performs boundary-scan test operations according to the protocol described in IEEE Standard 1149.1-1990.
Four dedicated test pins observe and control the operation of the test circuitry: test data input (TDI), test data
output (TDO), test mode select (TMS), and test clock (TCK). Additionally, the test circuitry performs other testing
functions such as parallel-signature analysis (PSA) on data inputs and pseudo-random pattern generation
(PRPG) from data outputs. All testing and scan operations are synchronized to the TAP interface.
Improved scan efficiency is accomplished through the adoption of a one boundary-scan cell (BSC) per I/O pin
architecture. This architecture is implemented in such a way as to capture the most pertinent test data. A
PSA/COUNT instruction also is included to ease the testing of memories and other circuits where a binary count
addressing scheme is useful.
Active bus-hold circuitry holds unused or floating data inputs at a valid logic level.
The B-port outputs of ’ABTH182646A, which are designed to source or sink up to 12 mA, include 25-Ω series
resistors to reduce overshoot and undershoot.
The SN54ABTH18646A and SN54ABTH182646A are characterized for operation over the full military
temperature range of –55°C to 125°C. The SN74ABTH18646A and SN74ABTH182646A are characterized for
operation from –40°C to 85°C.
FUNCTION TABLE
(normal mode, each 9-bit section)
INPUTS DATA I/O
OPERATION OR FUNCTION
OE DIR CLKAB CLKBA SAB SBA A1 – A9 B1 – B9
OPERATION
OR
FUNCTION
X X ↑X X X Input Unspecified†Store A, B unspecified†
XXX ↑X X Unspecified†Input Store B, A unspecified†
H X ↑ ↑ X X Input Input Store A and B data
HX L L X X Input disabled Input disabled Isolation, hold storage
L L X X X L Output Input Real-time B data to A bus
L L X X X H Output Input disabled Stored B data to A bus
L H X X L X Input Output Real-time A data to B bus
L H X X H X Input disabled Output Stored A data to B bus
†The data-output functions can be enabled or disabled by various signals at OE and DIR. Data-input functions are always enabled; i.e., data at
the bus pins is stored on every low-to-high transition of the clock inputs.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
4POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
LDIR
LCLKAB
XCLKBA
XSAB
XSBA
L
REAL-TIME TRANSFER
BUS B TO BUS A
LDIR
HCLKAB
XCLKBA
XSAB
LSBA
X
REAL-TIME TRANSFER
BUS A TO BUS B
XDIR
XCLKAB CLKBA
XSAB
XSBA
X
STORAGE FROM
A, B, OR A AND B
L
DIR
L
CLKAB
X
CLKBA
X
SAB
X
SBA
H
TRANSFER STORED DATA
TO A AND/OR B
X
HX
XXX
XX
XLH X XHX
↑↑
↑↑
BUS B
BUS A
BUS B
BUS A
BUS B
BUS A
BUS B
BUS A
OE OE
OEOE
Figure 1. Bus-Management Functions
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
functional block diagram
Boundary-Scan Register
One of Nine Channels
1OE
1DIR
1CLKBA
1SBA
1CLKAB
1SAB
1A1 1B1
1D
C1
1D
C1
One of Nine Channels
2OE
2DIR
2CLKBA
2SBA
2CLKAB
2SAB
2A1 2B1
1D
C1
1D
C1
Boundary-Control
Register
Instruction
Register
TDI
TMS
TCK
TDO
TAP
Controller
VCC
VCC
Bypass Register
Identification
Register
62
53
55
54
59
60
63
21
30
27
28
23
22
10
24
56
26
51
40
58
VCC
VCC
Pin numbers shown are for the PM package.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
6POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Terminal Functions
TERMINAL NAME DESCRIPTION
1A1–1A9,
2A1–2A9 Normal-function A-bus I/O ports. See function table for normal-mode logic.
1B1–1B9,
2B1–2B9 Normal-function B-bus I/O ports. See function table for normal-mode logic.
1CLKAB, 1CLKBA,
2CLKAB, 2CLKBA Normal-function clock inputs. See function table for normal-mode logic.
1DIR, 2DIR Normal-function direction controls. See function table for normal-mode logic.
GND Ground
1OE, 2OE Normal-function output enables. See function table for normal-mode logic. An internal pullup at each terminal forces the
terminal to a high level if left unconnected.
1SAB, 1SBA,
2SAB, 2SBA Normal-function select controls. See function table for normal-mode logic.
TCK T est clock. One of four terminals required by IEEE Standard 1149.1-1990. T est operations of the device are synchronous
to TCK. Data is captured on the rising edge of TCK and outputs change on the falling edge of TCK.
TDI Test data input. One of four terminals required by IEEE Standard 1149.1-1990. TDI is the serial input for shifting data
through the instruction register or selected data register . An internal pullup forces TDI to a high level if left unconnected.
TDO T est data output. One of four terminals required by IEEE Standard 1 149.1-1990. TDO is the serial output for shifting data
through the instruction register or selected data register.
TMS T est mode select. One of four terminals required by IEEE Standard 1149.1-1990. TMS directs the device through its TAP
controller states. An internal pullup forces TMS to a high level if left unconnected.
VCC Supply voltage
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
test architecture
Serial-test information is conveyed by means of a 4-wire test bus or TAP that conforms to IEEE Standard
1149.1-1990. All test instructions, test data, and test control signals are passed along this serial-test bus. The
TAP controller monitors two signals from the test bus, TCK and TMS. The function of the TAP controller is to
extract the synchronization (TCK) and state control (TMS) signals from the test bus and generate the
appropriate on-chip control signals for the test structures in the device. Figure 2 shows the T AP-controller state
diagram.
The T AP controller is fully synchronous to the TCK signal. Input data is captured on the rising edge of TCK and
output data changes on the falling edge of TCK. This scheme ensures data to be captured is valid for fully
one-half of the TCK cycle.
The functional block diagram shows the IEEE Standard 1149.1-1990 4-wire test bus and boundary-scan
architecture and the relationship among the test bus, the TAP controller , and the test registers. As shown, the
device contains an 8-bit instruction register and four test-data registers: a 52-bit boundary-scan register , a 3-bit
boundary-control register, a 1-bit bypass register, and a 32-bit device-identification register.
Test-Logic-Reset
Run-Test/Idle Select-DR-Scan
Capture-DR
Shift-DR
Exit1-DR
Pause-DR
Update-DR
TMS = L
TMS = L
TMS = H
TMS = L
TMS = H
TMS = H
TMS = LTMS = H
TMS = L
TMS = L
TMS = H
TMS = L
Exit2-DR
Select-IR-Scan
Capture-IR
Shift-IR
Exit1-IR
Pause-IR
Update-IR
TMS = L
TMS = L
TMS = H
TMS = L
TMS = H
TMS = H
TMS = LTMS = H
TMS = L Exit2-IR
TMS = L
TMS = H TMS = H
TMS = H
TMS = L
TMS = H
TMS = L
TMS = HTMS = H
TMS = H
TMS = L
Figure 2. TAP-Controller State Diagram
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
8POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
state diagram description
The TAP controller is a synchronous finite state machine that provides test control signals throughout the device.
The state diagram shown in Figure 2 is in accordance with IEEE Standard 1149.1-1990. The TAP controller
proceeds through its states based on the level of TMS at the rising edge of TCK.
As shown, the TAP controller consists of 16 states. There are six stable states (indicated by a looping arrow in
the state diagram) and ten unstable states. A stable state is a state the T AP controller can retain for consecutive
TCK cycles. Any state that does not meet this criterion is an unstable state.
There are two main paths through the state diagram: one to access and control the selected data register and
one to access and control the instruction register. Only one register can be accessed at a time.
Test-Logic-Reset
The device powers up in the Test-Logic-Reset state. In the stable Test-Logic-Reset state, the test logic is reset
and is disabled so that the normal logic function of the device is performed. The instruction register is reset to
an opcode that selects the optional IDCODE instruction, if supported, or the BYPASS instruction. Certain data
registers also can be reset to their power-up values.
The state machine is constructed such that the T AP controller returns to the Test-Logic-Reset state in no more
than five TCK cycles if TMS is left high. The TMS pin has an internal pullup resistor that forces it high if left
unconnected or if a board defect causes it to be open circuited.
For the ’ABTH18646A and ’ABTH182646A, the instruction register is reset to the binary value 10000001, which
selects the IDCODE instruction. Bits 51–48 in the boundary-scan register are reset to logic 0, ensuring that
these cells, which control A-port and B-port outputs, are set to benign values (i.e., if test mode were invoked,
the outputs would be at high-impedance state). Reset values of other bits in the boundary-scan register should
be considered indeterminate. The boundary-control register is reset to the binary value 010, which selects the
PSA test operation.
Run-Test/Idle
The TAP controller must pass through the Run-T est/Idle state (from T est-Logic-Reset) before executing any test
operations. The Run-Test/Idle state also can be entered following-data register or instruction-register scans.
Run-Test/Idle is provided as a stable state in which the test logic can be actively running a test or can be idle.
The test operations selected by the boundary-control register are performed while the TAP controller is in the
Run-Test/Idle state.
Select-DR-Scan, Select-lR-Scan
No specific function is performed in the Select-DR-Scan and Select-lR-Scan states, and the TAP controller exits
either of these states on the next TCK cycle. These states allow the selection of either data-register scan or
instruction-register scan.
Capture-DR
When a data-register scan is selected, the TAP controller must pass through the Capture-DR state. In the
Capture-DR state, the selected data register can capture a data value as specified by the current instruction.
Such capture operations occur on the rising edge of TCK, upon which the TAP controller exits the Capture-DR
state.
Shift-DR
Upon entry to the Shift-DR state, the data register is placed in the scan path between TDI and TDO, and on the
first falling edge of TCK, TDO goes from the high-impedance state to an active state. TDO enables to the logic
level present in the least-significant bit of the selected data register.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Shift-DR (continued)
While in the stable Shift-DR state, data is serially shifted through the selected data register on each TCK cycle.
The first shift occurs on the first rising edge of TCK after entry to the Shift-DR state (i.e., no shifting occurs during
the TCK cycle in which the T AP controller changes from Capture-DR to Shift-DR or from Exit2-DR to Shift-DR).
The last shift occurs on the rising edge of TCK, upon which the TAP controller exits the Shift-DR state.
Exit1-DR, Exit2-DR
The Exit1-DR and Exit2-DR states are temporary states that end a data-register scan. It is possible to return
to the Shift-DR state from either Exit1-DR or Exit2-DR without recapturing the data register. On the first falling
edge of TCK after entry to Exit1-DR, TDO goes from the active state to the high-impedance state.
Pause-DR
No specific function is performed in the stable Pause-DR state, in which the TAP controller can remain
indefinitely. The Pause-DR state can suspend and resume data register-scan operations without loss of data.
Update-DR
If the current instruction calls for the selected data register to be updated with current data, such update occurs
on the falling edge of TCK, following entry to the Update-DR state.
Capture-IR
When an instruction-register scan is selected, the TAP controller must pass through the Capture-IR state. In
the Capture-IR state, the instruction register captures its current status value. This capture operation occurs
on the rising edge of TCK, upon which the T AP controller exits the Capture-IR state. For the ’ABTH18646A and
’ABTH182646A, the status value loaded in the Capture-IR state is the fixed binary value 10000001.
Shift-IR
Upon entry to the Shift-IR state, the instruction register is placed in the scan path between TDI and TDO, and
on the first falling edge of TCK, TDO goes from the high-impedance state to an active state. TDO enables to
the logic level present in the least-significant bit of the instruction register.
While in the stable Shift-IR state, instruction data is serially shifted through the instruction register on each TCK
cycle. The first shift occurs on the first rising edge of TCK after entry to the Shift-IR state (i.e., no shifting occurs
during the TCK cycle, in which the TAP controller changes from Capture-IR to Shift-IR or from Exit2-IR to
Shift-IR). The last shift occurs on the rising edge of TCK, upon which the T AP controller exits the Shift-IR state.
Exit1-IR, Exit2-IR
The Exit1-IR and Exit2-IR states are temporary states that end an instruction-register scan. It is possible to
return to the Shift-IR state from either Exit1-IR or Exit2-IR without recapturing the instruction register. On the
first falling edge of TCK after entry to Exit1-IR, TDO goes from the active state to the high-impedance state.
Pause-IR
No specific function is performed in the stable Pause-IR state, in which the TAP controller can remain
indefinitely. The Pause-IR state can suspend and resume instruction-register scan operations without loss of
data.
Update-IR
The current instruction is updated and takes effect on the falling edge of TCK, following entry to the Update-IR
state.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
register overview
With the exception of the bypass and device-identification registers, any test register can be thought of as a
serial-shift register with a shadow latch on each bit. The bypass and device-identification registers differ in that
they contain only a shift register. During the appropriate capture state (Capture-IR for instruction register,
Capture-DR for data registers), the shift register can be parallel loaded from a source specified by the current
instruction. During the appropriate shift state (Shift-IR or Shift-DR), the contents of the shift register are shifted
out from TDO while new contents are shifted in at TDI. During the appropriate update state (Update-IR or
Update-DR), the shadow latches are updated from the shift register.
instruction register description
The instruction register (IR) is eight bits long and tells the device what instruction is to be executed. Information
contained in the instruction includes the mode of operation (either normal mode, in which the device performs
its normal logic function, or test mode, in which the normal logic function is inhibited or altered), the test operation
to be performed, which of the four data registers is to be selected for inclusion in the scan path during
data-register scans, and the source of data to be captured into the selected data register during Capture-DR.
Table 3 lists the instructions supported by the ’ABTH18646A and ’ABTH182646A. The even-parity feature
specified for SCOPE devices is supported in this device. Bit 7 of the instruction opcode is the parity bit. Any
instructions that are defined for SCOPE devices but are not supported by this device default to BYPASS.
During Capture-IR, the IR captures the binary value 10000001. As an instruction is shifted in, this value is shifted
out via TDO and can be inspected as verification that the IR is in the scan path. During Update-IR, the value
that has been shifted into the IR is loaded into shadow latches. At this time, the current instruction is updated
and any specified mode change takes effect. At power up or in the Test-Logic-Reset state, the IR is reset to the
binary value 10000001, which selects the IDCODE instruction. The IR order of scan is shown in Figure 3.
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 TDOTDI Bit 7
Parity
(MSB)
Bit 0
(LSB)
Figure 3. Instruction Register Order of Scan
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
data register description
boundary-scan register
The boundary-scan register (BSR) is 52 bits long. It contains one boundary-scan cell (BSC) for each
normal-function input pin, one BSC for each normal-function I/O pin (one single cell for both input data and
output data), and one BSC for each of the internally decoded output-enable signals (1OEA, 2OEA, 1OEB,
2OEB). The BSR is used 1) to store test data that is to be applied externally to the device output pins, and/or
2) to capture data that appears internally at the outputs of the normal on-chip logic and/or externally at the device
input pins.
The source of data to be captured into the BSR during Capture-DR is determined by the current instruction. The
contents of the BSR can change during Run-Test/Idle as determined by the current instruction. At power up or
in Test-Logic-Reset, BSCs 51–48 are reset to logic 0, ensuring that these cells, which control A-port and B-port
outputs, are set to benign values (i.e., if test mode were invoked, the outputs would be at high-impedance state).
Reset values of other BSCs should be considered indeterminate.
When external data is to be captured, the BSCs for signals 1OEA, 2OEA, 1OEB, and 2OEB capture logic values
determined by the following positive-logic equations: 1OEA = 1OE • 1DIR, 2OEA = 2OE • 2DIR,
1OEB = 1OE • DIR, and 2OEB = 2OE • DIR. When data is to be applied externally, these BSCs control the
drive state (active or high impedance) of their respective outputs.
The BSR order of scan is from TDI through bits 51–0 to TDO. Table 1 shows the BSR bits and their associated
device pin signals.
Table 1. Boundary-Scan Register Configuration
BSR BIT
NUMBER DEVICE
SIGNAL BSR BIT
NUMBER DEVICE
SIGNAL BSR BIT
NUMBER DEVICE
SIGNAL
51 2OEB 35 2A9-I/O 17 2B9-I/O
50 1OEB 34 2A8-I/O 16 2B8-I/O
49 2OEA 33 2A7-I/O 15 2B7-I/O
48 1OEA 32 2A6-I/O 14 2B6-I/O
47 2DIR 31 2A5-I/O 13 2B5-I/O
46 1DIR 30 2A4-I/O 12 2B4-I/O
45 2OE 29 2A3-I/O 11 2B3-I/O
44 1OE 28 2A2-I/O 10 2B2-I/O
43 2CLKAB 27 2A1-I/O 9 2B1-I/O
42 1CLKAB 26 1A9-I/O 8 1B9-I/O
41 2CLKBA 25 1A8-I/O 7 1B8-I/O
40 1CLKBA 24 1A7-I/O 6 1B7-I/O
39 2SAB 23 1A6-I/O 5 1B6-I/O
38 1SAB 22 1A5-I/O 4 1B5-I/O
37 2SBA 21 1A4-I/O 3 1B4-I/O
36 1SBA 20 1A3-I/O 2 1B3-I/O
19 1A2-I/O 1 1B2-I/O
18 1A1-I/O 0 1B1-I/O
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
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boundary-control register
The boundary-control register (BCR) is three bits long. The BCR is used in the context of the boundary-run test
(RUNT) instruction to implement additional test operations not included in the basic SCOPE instruction set.
Such operations include PRPG, PSA, and binary count up (COUNT). Table 4 shows the test operations that
are decoded by the BCR.
During Capture-DR, the contents of the BCR are not changed. At power up or in Test-Logic-Reset, the BCR is
reset to the binary value 010, which selects the PSA test operation. The BCR order of scan is shown in
Figure 4.
Bit 0
(LSB) TDOTDI Bit 1
Bit 2
(MSB)
Figure 4. Boundary-Control Register Order of Scan
bypass register
The bypass register is a 1-bit scan path that can be selected to shorten the length of the system scan path,
reducing the number of bits per test pattern that must be applied to complete a test operation. During
Capture-DR, the bypass register captures a logic 0. The bypass register order of scan is shown in
Figure 5.
Bit 0 TDOTDI
Figure 5. Bypass Register Order of Scan
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device-identification register
The device-identification register (IDR) is 32 bits long. It can be selected and read to identify the manufacturer ,
part number, and version of this device.
For the ’ABTH18646A , the binary value 00000000000000101001000000101111 (0002902F, hex) is captured
(during Capture-DR state) in the IDR to identify this device as Texas Instruments SN54/74ABTH18646A.
For the ’ABTH182646A , the binary value 00000000000000101 101000000101111 (0002D02F , hex) is captured
(during Capture-DR state) in the IDR to identify this device as Texas Instruments SN54/74ABTH182646A.
The IDR order of scan is from TDI through bits 31–0 to TDO. Table 2 shows the IDR bits and their significance.
Table 2. Device-Identification Register Configuration
IDR BIT
NUMBER IDENTIFICATION
SIGNIFICANCE IDR BIT
NUMBER IDENTIFICATION
SIGNIFICANCE IDR BIT
NUMBER IDENTIFICATION
SIGNIFICANCE
31 VERSION3 27 PARTNUMBER15 11 MANUFACTURER10†
30 VERSION2 26 PARTNUMBER14 10 MANUFACTURER09†
29 VERSION1 25 PARTNUMBER13 9 MANUFACTURER08†
28 VERSION0 24 PARTNUMBER12 8 MANUFACTURER07†
23 PARTNUMBER11 7 MANUFACTURER06†
22 PARTNUMBER10 6 MANUFACTURER05†
21 PARTNUMBER09 5 MANUFACTURER04†
20 PARTNUMBER08 4 MANUFACTURER03†
19 PARTNUMBER07 3 MANUFACTURER02†
18 PARTNUMBER06 2 MANUFACTURER01†
17 PARTNUMBER05 1 MANUFACTURER00†
16 PARTNUMBER04 0 LOGIC1†
15 PARTNUMBER03
14 PARTNUMBER02
13 PARTNUMBER01
12 PARTNUMBER00
†Note that for TI products, bits 11–0 of the device-identification register always contain the binary value 000000101111
(02F, hex).
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instruction-register opcode description
The instruction-register opcodes are shown in Table 3. The following descriptions detail the operation of each
instruction.
Table 3. Instruction-Register Opcodes
BINARY CODE†
BIT 7 → BIT 0
MSB → LSB SCOPE OPCODE DESCRIPTION SELECTED DATA
REGISTER MODE
00000000 EXTEST Boundary scan Boundary scan Test
10000001 IDCODE Identification read Device identification Normal
10000010 SAMPLE/PRELOAD Sample boundary Boundary scan Normal
00000011 BYPASS‡Bypass scan Bypass Normal
10000100 BYPASS‡Bypass scan Bypass Normal
00000101 BYPASS‡Bypass scan Bypass Normal
00000110 HIGHZ Control boundary to high impedance Bypass Modified test
10000111 CLAMP Control boundary to 1/0 Bypass Test
10001000 BYPASS‡Bypass scan Bypass Normal
00001001 RUNT Boundary-run test Bypass Test
00001010 READBN Boundary read Boundary scan Normal
10001011 READBT Boundary read Boundary scan Test
00001100 CELLTST Boundary self test Boundary scan Normal
10001101 TOPHIP Boundary toggle outputs Bypass Test
10001110 SCANCN Boundary-control register scan Boundary control Normal
00001111 SCANCT Boundary-control register scan Boundary control Test
All others BYPASS Bypass scan Bypass Normal
†Bit 7 is used to maintain even parity in the 8-bit instruction.
‡The BYPASS instruction is executed in lieu of a SCOPE instruction that is not supported in the ’ABTH18646A or ’ABTH182646A.
boundary scan
This instruction conforms to the IEEE Standard 1149.1-1990 EXTEST instruction. The BSR is selected in the
scan path. Data appearing at the device input and I/O pins is captured in the associated BSCs. Data that has
been scanned into the I/O BSCs for pins in the output mode is applied to the device I/O pins. Data present at
the device pins is passed through the BSCs to the normal on-chip logic. For I/O pins, the operation of a pin as
input or output is determined by the contents of the output-enable BSCs (bits 51–48 of the BSR). When a given
output enable is active (logic 1), the associated I/O pins operate in the output mode. Otherwise, the I/O pins
operate in the input mode. The device operates in the test mode.
identification read
This instruction conforms to the IEEE Standard 1149.1-1990 IDCODE instruction. The IDR is selected in the
scan path. The device operates in the normal mode.
sample boundary
This instruction conforms to the IEEE Standard 1149.1-1990 SAMPLE/PRELOAD instruction. The BSR is
selected in the scan path. Data appearing at the device input pins and I/O pins in the input mode is captured
in the associated BSCs, while data appearing at the outputs of the normal on-chip logic is captured in the BSCs
associated with I/O pins in the output mode. The device operates in the normal mode.
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bypass scan
This instruction conforms to the IEEE Standard 1149.1-1990 BYPASS instruction. The bypass register is
selected in the scan path. A logic 0 value is captured in the bypass register during Capture-DR. The device
operates in the normal mode.
control boundary to high impedance
This instruction conforms to the IEEE Standard 1149.1a-1993 HIGHZ instruction. The bypass register is
selected in the scan path. A logic 0 value is captured in the bypass register during Capture-DR. The device
operates in a modified test mode in which all device I/O pins are placed in the high-impedance state, the device
input pins remain operational, and the normal on-chip logic function is performed.
control boundary to 1/0
This instruction conforms to the IEEE Standard 1149.1a-1993 CLAMP instruction. The bypass register is
selected in the scan path. A logic 0 value is captured in the bypass register during Capture-DR. Data in the I/O
BSCs for pins in the output mode is applied to the device I/O pins. The device operates in the test mode.
boundary-run test
The bypass register is selected in the scan path. A logic 0 value is captured in the bypass register during
Capture-DR. The device operates in the test mode. The test operation specified in the BCR is executed during
Run-Test/Idle. The five test operations decoded by the BCR are: sample inputs/toggle outputs (TOPSIP),
PRPG, PSA, simultaneous PSA and PRPG (PSA/PRPG), and simultaneous PSA and binary count up
(PSA/COUNT).
boundary read
The BSR is selected in the scan path. The value in the BSR remains unchanged during Capture-DR. This
instruction is useful for inspecting data after a PSA operation.
boundary self test
The BSR is selected in the scan path. All BSCs capture the inverse of their current values during Capture-DR.
In this way, the contents of the shadow latches can be read out to verify the integrity of both shift-register and
shadow-latch elements of the BSR. The device operates in the normal mode.
boundary toggle outputs
The bypass register is selected in the scan path. A logic 0 value is captured in the bypass register during
Capture-DR. Data in the shift-register elements of the selected output-mode BSCs is toggled on each rising
edge of TCK in Run-Test/Idle, updated in the shadow latches, and applied to the associated device I/O pins on
each falling edge of TCK in Run-Test/Idle. Data in the input-mode BSCs remains constant. Data appearing at
the device input or I/O pins is not captured in the input-mode BSCs. The device operates in the test mode.
boundary-control-register scan
The BCR is selected in the scan path. The value in the BCR remains unchanged during Capture-DR. This
operation must be performed before a boundary-run test operation to specify which test operation is to be
executed.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
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boundary-control register opcode description
The BCR opcodes are decoded from BCR bits 2–0 as shown in T able 4. The selected test operation is performed
while the RUNT instruction is executed in the Run-T est/Idle state. The following descriptions detail the operation
of each BCR instruction and illustrate the associated PSA and PRPG algorithms.
Table 4. Boundary-Control Register Opcodes
BINARY CODE
BIT 2 → BIT 0
MSB → LSB DESCRIPTION
X00 Sample inputs/toggle outputs (TOPSIP)
X01 Pseudo-random pattern generation/36-bit mode (PRPG)
X10 Parallel-signature analysis/36-bit mode (PSA)
011 Simultaneous PSA and PRPG/18-bit mode (PSA/PRPG)
111 Simultaneous PSA and binary count up/18-bit mode (PSA/COUNT)
While the control input BSCs (bits 51–36) are not included in the toggle, PSA, PRPG, or COUNT algorithms,
the output-enable BSCs (bits 51–48 of the BSR) control the drive state (active or high impedance) of the selected
device output pins. These BCR instructions are valid only when both bytes of the device are operating in one
direction of data flow (that is, 1OEA ≠ 1OEB and 2OEA ≠ 2OEB) and in the same direction of data flow (that is,
1OEA = 2OEA and 1OEB = 2OEB). Otherwise, the bypass instruction is operated.
sample inputs/toggle outputs (TOPSIP)
Data appearing at the selected device input-mode I/O pins is captured in the shift-register elements of the
associated BSCs on each rising edge of TCK. Data in the shift-register elements of the selected output-mode
BSCs is toggled on each rising edge of TCK, updated in the shadow latches, and applied to the associated
device I/O pins on each falling edge of TCK.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
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pseudo-random pattern generation (PRPG)
A pseudo-random pattern is generated in the shift-register elements of the selected BSCs on each rising edge
of TCK, updated in the shadow latches, and applied to the associated device output-mode I/O pins on each
falling edge of TCK. Figures 6 and 7 illustrate the 36-bit linear-feedback shift-register algorithms through which
the patterns are generated. An initial seed value should be scanned into the BSR before performing this
operation. A seed value of all zeroes does not produce additional patterns.
=1B8-I/O 1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B9-I/O
1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A8-I/O1A9-I/O
2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A8-I/O2A9-I/O
2B8-I/O 2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B9-I/O
Figure 6. 36-Bit PRPG Configuration (1OEA = 2OEA = 0, 1OEB = 2OEB = 1)
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
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pseudo-random pattern generation (PRPG) (continued)
1A8-I/O 1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A9-I/O
1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B8-I/O1B9-I/O
2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B8-I/O2B9-I/O
2A8-I/O 2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A9-I/O
=
Figure 7. 36-Bit PRPG Configuration (1OEA = 2OEA = 1, 1OEB = 2OEB = 0)
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parallel-signature analysis (PSA)
Data appearing at the selected device input-mode I/O pins is compressed into a 36-bit parallel signature in the
shift-register elements of the selected BSCs on each rising edge of TCK. Data in the shadow latches of the
selected output-mode BSCs remains constant and is applied to the associated device I/O pins. Figures 8 and 9
illustrate the 36-bit linear-feedback shift-register algorithms through which the signature is generated. An initial
seed value should be scanned into the BSR before performing this operation.
=
1B8-I/O 1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B9-I/O
1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A8-I/O1A9-I/O
2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A8-I/O2A9-I/O
2B8-I/O 2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B9-I/O
=
Figure 8. 36-Bit PSA Configuration (1OEA = 2OEA = 0, 1OEB = 2OEB = 1)
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parallel-signature analysis (PSA) (continued)
1A8-I/O 1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A9-I/O
1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B8-I/O1B9-I/O
2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B8-I/O2B9-I/O
2A8-I/O 2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A9-I/O
=
=
Figure 9. 36-Bit PSA Configuration (1OEA = 2OEA = 1, 1OEB = 2OEB = 0)
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
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simultaneous PSA and PRPG (PSA/PRPG)
Data appearing at the selected device input-mode I/O pins is compressed into an 18-bit parallel signature in
the shift-register elements of the selected input-mode BSCs on each rising edge of TCK. At the same time, an
18-bit pseudo-random pattern is generated in the shift-register elements of the selected output-mode BSCs on
each rising edge of TCK, updated in the shadow latches, and applied to the associated device I/O pins on each
falling edge of TCK. Figures 10 and 11 illustrate the 18-bit linear-feedback shift-register algorithms through
which the signature and patterns are generated. An initial seed value should be scanned into the BSR before
performing this operation. A seed value of all zeroes does not produce additional patterns.
1B8-I/O 1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B9-I/O
1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A8-I/O1A9-I/O
2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A8-I/O2A9-I/O
2B8-I/O 2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B9-I/O
=
=
Figure 10. 18-Bit PSA/PRPG Configuration (1OEA = 2OEA = 0, 1OEB = 2OEB = 1)
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simultaneous PSA and PRPG (PSA/PRPG) (continued)
1A8-I/O 1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A9-I/O
1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B8-I/O1B9-I/O
2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B8-I/O2B9-I/O
2A8-I/O 2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A9-I/O
=
=
Figure 11. 18-Bit PSA/PRPG Configuration (1OEA = 2OEA = 1, 1OEB = 2OEB = 0)
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simultaneous PSA and binary count up (PSA/COUNT)
Data appearing at the selected device input-mode I/O pins is compressed into an 18-bit parallel signature in
the shift-register elements of the selected input-mode BSCs on each rising edge of TCK. At the same time, an
18-bit binary count-up pattern is generated in the shift-register elements of the selected output-mode BSCs on
each rising edge of TCK, updated in the shadow latches, and applied to the associated device I/O pins on each
falling edge of TCK. Figures 12 and 13 illustrate the 18-bit linear-feedback shift-register algorithms through
which the signature is generated. An initial seed value should be scanned into the BSR before performing this
operation.
1B8-I/O 1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B9-I/O
1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A8-I/O1A9-I/O
2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A8-I/O2A9-I/O
2B8-I/O 2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B9-I/O
MSB
LSB
=
=
Figure 12. 18-Bit PSA/COUNT Configuration (1OEA = 2OEA = 0, 1OEB = 2OEB = 1)
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simultaneous PSA and binary count up (PSA/COUNT) (continued)
1A8-I/O 1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O1A9-I/O
1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O1B8-I/O
MSB
2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O2B8-I/O2B9-I/O
2A8-I/O 2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O2A9-I/O
LSB
1B9-I/O
=
=
Figure 13. 18-Bit PSA/COUNT Configuration (1OEA = 2OEA = 1, 1OEB = 2OEB = 0)
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timing description
All test operations of the ’ABTH18646A and ’ABTH182646A are synchronous to TCK. Data on the TDI, TMS,
and normal-function inputs is captured on the rising edge of TCK. Data appears on the TDO and normal-function
output pins on the falling edge of TCK. The T AP controller is advanced through its states (as shown in Figure 2)
by changing the value of TMS on the falling edge of TCK and then applying a rising edge to TCK.
A simple timing example is shown in Figure 14. In this example, the TAP controller begins in the
Test-Logic-Reset state and is advanced through its states, as necessary, to perform one instruction-register
scan and one data-register scan. While in the Shift-IR and Shift-DR states, TDI is used to input serial data, and
TDO is used to output serial data. The TAP controller is then returned to the Test-Logic-Reset state. Table 5
details the operation of the test circuitry during each TCK cycle.
Table 5. Explanation of Timing Example
TCK
CYCLE(S) TAP STATE
AFTER TCK DESCRIPTION
1 Test-Logic-Reset TMS is changed to a logic 0 value on the falling edge of TCK to begin advancing the T AP controller toward
the desired state.
2 Run-Test/Idle
3 Select-DR-Scan
4 Select-IR-Scan
5 Capture-IR The IR captures the 8-bit binary value 10000001 on the rising edge of TCK as the T AP controller exits the
Capture-IR state.
6 Shift-IR TDO becomes active and TDI is made valid on the falling edge of TCK. The first bit is shifted into the TAP
on the rising edge of TCK as the TAP controller advances to the next state.
7–13 Shift-IR
One bit is shifted into the IR on each TCK rising edge. With TDI held at a logic 1 value, the 8-bit binary value
11111111 is serially scanned into the IR. At the same time, the 8-bit binary value 10000001 is serially scanned
out of the IR via TDO. In TCK cycle 13, TMS is changed to a logic 1 value to end the IR scan on the next
TCK cycle. The last bit of the instruction is shifted as the T AP controller advances from Shift-IR to Exit1-IR.
14 Exit1-IR TDO becomes inactive (goes to the high-impedance state) on the falling edge of TCK.
15 Update-IR The IR is updated with the new instruction (BYPASS) on the falling edge of TCK.
16 Select-DR-Scan
17 Capture-DR The bypass register captures a logic 0 value on the rising edge of TCK as the TAP controller exits the
Capture-DR state.
18 Shift-DR TDO becomes active and TDI is made valid on the falling edge of TCK. The first bit is shifted into the TAP
on the rising edge of TCK as the TAP controller advances to the next state.
19–20 Shift-DR The binary value 101 is shifted in via TDI, while the binary value 010 is shifted out via TDO.
21 Exit1-DR TDO becomes inactive (goes to the high-impedance state) on the falling edge of TCK.
22 Update-DR In general, the selected data register is updated with the new data on the falling edge of TCK.
23 Select-DR-Scan
24 Select-IR-Scan
25 Test-Logic-Reset Test operation completed
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
26 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
timing description (continued)
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎ
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
Test-Logic-Reset
Run-Test/Idle
Select-DR-Scan
Select-IR-Scan
Capture-IR
Shift-IR
Exit1-IR
Update-IR
Select-DR-Scan
Capture-DR
Shift-DR
Exit1-DR
Update-DR
Select-DR-Scan
Select-IR-Scan
Test-Logic-Reset
TCK
TMS
TDI
TDO
ÎÎ
TAP
Controller
State
3-State (TDO) or Don’t Care (TDI)
Figure 14. Timing Example
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, VI: except I/O ports (see Note 1) –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O ports (see Note 1) –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the high state or power-off state, VO –0.5 V to 5.5 V. . . . . . . . . . . . . .
Current into any output in the low state, IO: SN54ABTH18646A 96 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN54ABTH182646A (A port or TDO) 96 mA. . . . . . . . . . . . . . . .
SN54ABTH182646A (B port) 30 mA. . . . . . . . . . . . . . . . . . . . . . .
SN74ABTH18646A 128 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74ABTH182646A (A port or TDO) 128 mA. . . . . . . . . . . . . . .
SN74ABTH182646A (B port) 30 mA. . . . . . . . . . . . . . . . . . . . . . .
Input clamp current, IIK (VI < 0) –18 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output clamp current, IOK (VO < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum package power dissipation at TA = 55°C (in still air) (see Note 2): PM package 1 W. . . . . . . . . . .
Storage temperature range, Tstg – 65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only , and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may af fect device reliability.
NOTES: 1. The input and output negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
2. The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 75 mils.
For more information, refer to the
Package Thermal Considerations
application note in the
ABT Advanced BiCMOS T echnology Data
Book
, literature number SCBD002.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
27
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
SN54ABTH18646A SN74ABTH18646A
UNIT
MIN MAX MIN MAX
UNIT
VCC Supply voltage 4.5 5.5 4.5 5.5 V
VIH High-level input voltage 2 2 V
VIL Low-level input voltage 0.8 0.8 V
VIInput voltage 0 VCC 0 VCC V
IOH High-level output current –24 –32 mA
IOL Low-level output current 48 64 mA
∆t/∆vInput transition rise or fall rate 10 10 ns/V
TAOperating free-air temperature –55 125 –40 85 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54ABTH18646A
PARAMETER TEST CONDITIONS TA = 25°C TA = –55°C to 125°CUNIT
MIN TYP†MAX MIN MAX
VIK VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
VCC = 4.5 V, IOH = –3 mA 2.5 2.5
VOH VCC = 5 V, IOH = –3 mA 3 3 V
VCC = 4.5 V, IOH = –24 mA 2 2
VOL VCC = 4.5 V, IOL = 48 mA 0.55 0.55 V
IICLK, DIR, S, TCK
VCC = 0 to 5.5 V, VCC = 0 to 5.5 V, VI = VCC or GND ±1±1µA
I
A or B ports VCC = 5.5 V, VI = VCC or GND ±20 ±20
µ
IIH OE, TDI, TMS VCC = 5.5 V, VI = VCC 10 10 µA
IIL OE, TDI, TMS VCC = 5.5 V, VI = GND –40 –150 –40 –150 µA
II(h ld)‡
AorB
p
orts
VCC =45V
VI = 0.8 V 75 220 500
µA
I
I(hold)
‡
A
or
B
ports
V
CC =
4
.
5
V
VI = 2 V –75 –180 –500 µ
A
IOZH TDO VCC = 5.5 V, VO = 2.7 V, OE = 2 V 10 10 µA
IOZL TDO VCC = 5.5 V, VO = 0.5 V, OE = 2 V –10 –10 µA
IOZPU TDO VCC = 0 to 2.1 V,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 µA
IOZPD TDO VCC = 2.1 V to 0,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 µA
Ioff VCC = 0, VI or VO ≤ 4.5 V ±100 µA
ICEX Outputs high VCC = 5.5 V, VO = 5.5 V 50 50 µA
IO§VCC = 5.5 V, VO = 2.5 V –50 –110 –200 –50 –200 mA
Outputs high V
CC
= 5.5 V
,
1.7 3.9 3.9
ICC Outputs low
VCC
5.5
V,
IO = 0, A or B ports 20 24 24 mA
Outputs disabled VI = VCC or GND 1 3 3
∆ICC¶VCC = 5.5 V, One input at 3.4 V,
Other inputs at VCC or GND 1.5 1.5 mA
CiControl inputs VI = 2.5 V or 0.5 V 5 pF
Cio A or B ports VO = 2.5 V or 0.5 V 10 pF
CoTDO VO = 2.5 V or 0.5 V 8 pF
†All typical values are at VCC = 5 V.
‡The parameter II(hold) includes the off-state output leakage current.
§Not more than one output should be tested at a time, and the duration of the test should not exceed one second.
¶This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
28 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN74ABTH18646A
PARAMETER TEST CONDITIONS TA = 25°C TA = –40°C to 85°CUNIT
MIN TYP†MAX MIN MAX
VIK VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
VCC = 4.5 V, IOH = –3 mA 2.5 2.5
VOH
VCC = 5 V, IOH = –3 mA 3 3
V
V
OH
VCC =45V
IOH = –24 mA 2
V
V
CC =
4
.
5
V
IOH = –32 mA 2 2
VOL
VCC =45V
IOL = 48 mA 0.55 0.55
V
V
OL
V
CC =
4
.
5
V
IOL = 64 mA 0.55 0.55
V
I
I
CLK, DIR, S, TCK
VCC = 0 to 5.5 V, VCC = 0 to 5.5 V, VI = VCC or GND ±1±1
µ
A
I
A or B ports VCC = 5.5 V, VI = VCC or GND ±20 ±20
µ
IIH OE, TDI, TMS VCC = 5.5 V, VI = VCC 10 10 µA
IIL OE, TDI, TMS VCC = 5.5 V, VI = GND –40 –150 –40 –150 µA
I‡
AorB
p
orts
VCC =45V
VI = 0.8 V 75 220 500 75 500
µA
I
I(hold)
‡
A
or
B
ports
V
CC =
4
.
5
V
VI = 2 V –75 –180 –500 –75 –500 µ
A
IOZH TDO VCC = 2.1 V to 5.5 V,
VO = 2.7 V, OE = 2 V 10 10 µA
IOZL TDO VCC = 2.1 V to 5.5 V,
VO = 0.5 V, OE = 2 V –10 –10 µA
IOZPU TDO VCC = 0 to 2.1 V,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 ±50 µA
IOZPD TDO VCC = 2.1 V to 0,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 ±50 µA
Ioff VCC = 0, VI or VO ≤ 4.5 V ±100 ±100 µA
ICEX Outputs high VCC = 5.5 V, VO = 5.5 V 50 50 µA
IO§VCC = 5.5 V, VO = 2.5 V –50 –110 –200 –50 –200 mA
Outputs high
VCC
=
5.5 V,
1.7 2.2 2.2
ICC Outputs low
VCC
=
5
.
5
V
,
IO = 0, A or B ports 20 24 24 mA
Outputs disabled VI = VCC or GND 1 2 2
∆ICC¶VCC = 5.5 V, One input at 3.4 V,
Other inputs at VCC or GND 1.5 1.5 mA
CiControl inputs VI = 2.5 V or 0.5 V 5 pF
Cio A or B ports VO = 2.5 V or 0.5 V 10 pF
CoTDO VO = 2.5 V or 0.5 V 8 pF
†All typical values are at VCC = 5 V.
‡The parameter II(hold) includes the off-state output leakage current.
§Not more than one output should be tested at a time, and the duration of the test should not exceed one second.
¶This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
29
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 15)
SN54ABTH18646A SN74ABTH18646A
UNIT
MIN MAX MIN MAX
UNIT
fclock Clock frequency CLKAB or CLKBA 0 100 0 100 MHz
twPulse duration CLKAB or CLKBA high or low 3 3 ns
tsu Setup time A before CLKAB↑ or B before CLKBA↑3 3 ns
thHold time A after CLKAB↑ or B after CLKBA↑0.9 0.5 ns
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 15)
SN54ABTH18646A SN74ABTH18646A
UNIT
MIN MAX MIN MAX
UNIT
fclock Clock frequency TCK 0 50 0 50 MHz
twPulse duration TCK high or low 8 8 ns
A, B, CLK, DIR, OE, or S before TCK↑6 6
tsu Setup time TDI before TCK↑4.5 4.5 ns
TMS before TCK↑3 3
A, B, CLK, DIR, OE, or S after TCK↑1.5 1.5
thHold time TDI after TCK↑1 1 ns
TMS after TCK↑1.5 1.5
tdDelay time Power up to TCK↑50* 50 ns
trRise time VCC power up 1* 1µs
*On products compliant to MIL-PRF-38535, this parameter is not production tested.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
30 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 15)
SN54ABTH18646A
PARAMETER FROM
(INPUT) TO
(OUTPUT) VCC = 5 V,
TA = 25°CVCC = 4.5 V to 5.5 V,
TA = –55°C to 125°CUNIT
MIN TYP MAX MIN MAX
fmax CLKAB or CLKBA 100 150 100 MHz
tPLH
AorB
BorA
1.5 3.1 4.7 1.5 5.2
ns
tPHL
A
or
B
B
or
A
1.5 3.3 5.0 1.5 6
ns
tPLH
CLKAB or CLKBA
BorA
1.5 3.6 5.6 1.5 6.8
ns
tPHL
CLKAB
or
CLKBA
B
or
A
1.5 3.8 5.8 1.5 7
ns
tPLH
SAB or SBA
BorA
1.5 3.8 6.0 1.5 7.8
ns
tPHL
SAB
or
SBA
B
or
A
1.5 3.9 6.5 1.5 8.2
ns
tPZH
DIR
BorA
1.5 3.9 6.3 1.5 7.5
ns
tPZL
DIR
B
or
A
1.5 4 6.5 1.5 7.8
ns
tPZH
OE
BorA
1.5 4.2 6.7 1.5 7.6
ns
tPZL
OE
B
or
A
1.5 4.3 6.9 1.5 7.7
ns
tPHZ
DIR
BorA
2 5.9 8.8 2 10.3
ns
tPLZ
DIR
B
or
A
2 4.7 6.9 2 9.1
ns
tPHZ
OE
BorA
2 6 9 2 10.2
ns
tPLZ
OE
B
or
A
2 4.8 7.1 2 9.4
ns
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 15)
SN74ABTH18646A
PARAMETER FROM
(INPUT) TO
(OUTPUT) VCC = 5 V,
TA = 25°CVCC = 4.5 V to 5.5 V,
TA = –40°C to 85°CUNIT
MIN TYP MAX MIN MAX
fmax CLKAB or CLKBA 100 150 100 MHz
tPLH
AorB
BorA
1.5 3.1 4.7 1.5 5
ns
tPHL
A
or
B
B
or
A
1.5 3.3 5.0 1.5 5.4
ns
tPLH
CLKAB or CLKBA
BorA
1.5 3.6 5.6 1.5 5.9
ns
tPHL
CLKAB
or
CLKBA
B
or
A
1.5 3.8 5.8 1.5 6.1
ns
tPLH
SAB or SBA
BorA
1.5 3.8 6.0 1.5 6.6
ns
tPHL
SAB
or
SBA
B
or
A
1.5 3.9 6.5 1.5 6.8
ns
tPZH
DIR
BorA
1.5 3.9 6.3 1.5 7
ns
tPZL
DIR
B
or
A
1.5 4 6.5 1.5 7.2
ns
tPZH
OE
BorA
1.5 4.2 6.7 1.5 7.4
ns
tPZL
OE
B
or
A
1.5 4.3 6.9 1.5 7.6
ns
tPHZ
DIR
BorA
2 5.9 8.8 2 10
ns
tPLZ
DIR
B
or
A
2 4.7 6.9 2 8.1
ns
tPHZ
OE
BorA
2 6 9 2 9.7
ns
tPLZ
OE
B
or
A
2 4.8 7.1 2 7.6
ns
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
31
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 15)
SN54ABTH18646A
PARAMETER FROM
(INPUT) TO
(OUTPUT) VCC = 5 V,
TA = 25°CVCC = 4.5 V to 5.5 V,
TA = –40°C to 85°CUNIT
MIN TYP MAX MIN MAX
fmax TCK 50 90 50 MHz
tPLH
TCK↓
AorB
2.5 6.1 11 2.5 13.1
ns
tPHL
TCK↓
A
or
B
2.5 6.5 10.8 2.5 12.6
ns
tPLH
TCK↓
TDO
2 3.6 5.1 2 5.8
ns
tPHL
TCK↓
TDO
2 3.7 5.1 2 7
ns
tPZH
TCK↓
AorB
4 7.1 11.5 4 13.9
ns
tPZL
TCK↓
A
or
B
4 7.2 11.8 4 14.2
ns
tPZH
TCK↓
TDO
2 3.7 5.7 2 6.6
ns
tPZL
TCK↓
TDO
2 3.9 6.2 2 6.9
ns
tPHZ
TCK↓
AorB
4 8.5 14.2 4 18
ns
tPLZ
TCK↓
A
or
B
3 7.2 13.3 3 17.5
ns
tPHZ
TCK↓
TDO
3 5.1 6.8 3 7.4
ns
tPLZ
TCK↓
TDO
2.5 4 5.5 2.5 6.4
ns
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 15)
SN74ABTH18646A
PARAMETER FROM
(INPUT) TO
(OUTPUT) VCC = 5 V,
TA = 25°CVCC = 4.5 V to 5.5 V,
TA = –40°C to 85°CUNIT
MIN TYP MAX MIN MAX
fmax TCK 50 90 50 MHz
tPLH
TCK↓
AorB
2.5 6.1 11 2.5 13.1
ns
tPHL
TCK↓
A
or
B
2.5 6.5 10.8 2.5 12.4
ns
tPLH
TCK↓
TDO
2 3.6 5.1 2 5.6
ns
tPHL
TCK↓
TDO
2 3.7 5.1 2 5.6
ns
tPZH
TCK↓
AorB
4 7.1 11.5 4 13.4
ns
tPZL
TCK↓
A
or
B
4 7.2 11.8 4 13.6
ns
tPZH
TCK↓
TDO
2 3.7 5.7 2 6.6
ns
tPZL
TCK↓
TDO
2 3.9 6.2 2 6.9
ns
tPHZ
TCK↓
AorB
4 8.5 13 4 15
ns
tPLZ
TCK↓
A
or
B
3 7.2 13.3 3 15
ns
tPHZ
TCK↓
TDO
3 5.1 6.8 3 7.2
ns
tPLZ
TCK↓
TDO
2.5 4 5.5 2.5 6.3
ns
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
32 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
SN54ABTH182646A SN74ABTH182646A
UNIT
MIN MAX MIN MAX
UNIT
VCC Supply voltage 4.5 5.5 4.5 5.5 V
VIH High-level input voltage 2 2 V
VIL Low-level input voltage 0.8 0.8 V
VIInput voltage 0 VCC 0 VCC V
IOH
High level out
p
ut current
A port, TDO –24 –32
mA
I
OH
High
-
le
v
el
o
u
tp
u
t
c
u
rrent
B port –12 –12
mA
IOL
Low level out
p
ut current
A port, TDO 48 64
mA
I
OL
Lo
w-
le
v
el
o
u
tp
u
t
c
u
rrent
B port 12 12
mA
∆t/∆vInput transition rise or fall rate 10 10 ns/V
TAOperating free-air temperature –55 125 –40 85 °C
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
33
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
TA = 25°C SN54ABTH182646A SN74ABTH182646A
UNIT
PARAMETER
TEST
CONDITIONS
MIN TYP†MAX MIN MAX MIN MAX
UNIT
VIK VCC = 4.5 V, II = –18 mA –1.2 –1.2 –1.2 V
VCC = 4.5 V, IOH = –3 mA 2.5 2.5 2.5
A
p
ort TDO
VCC = 5 V, IOH = –3 mA 3 3 3
A
port
,
TDO
VCC =45V
IOH = –24 mA 2 2
VOH
V
CC =
4
.
5
V
IOH = –32 mA 2* 2
V
V
OH VCC = 4.5 V, IOH = –1 mA 3.35 3.3 3.35
V
B
p
ort
VCC = 5 V, IOH = –1 mA 3.85 3.8 3.85
B
port
VCC =45V
IOH = –3 mA 3.1 3 3.1
V
CC =
4
.
5
V
IOH = –12 mA 2.6* 2.6
A
p
ort TDO
VCC =45V
IOL = 48 mA 0.55 0.55
VOL
A
port
,
TDO
V
CC =
4
.
5
V
IOL = 64 mA 0.55* 0.55
V
V
OL
B
p
ort
VCC =45V
IOL = 8 mA 0.8 0.8 0.65
V
B
port
V
CC =
4
.
5
V
IOL = 12 mA 0.8* 0.8
II
CLK, DIR, S,
TCK VCC = 0 to 5.5 V,
VI = VCC or GND ±1±1±1
µA
I
IA or B ports VCC = 5.5 V,
VI = VCC or GND ±20 ±20 ±20 µ
A
IIH OE, TDI,
TMS VCC = 5.5 V, VI = VCC 10 10 10 µA
IIL OE, TDI,
TMS VCC = 5.5 V, VI = GND –40 –150 –40 –150 –40 –150 µA
II(h ld)‡
AorB
p
orts
VCC =45V
VI = 0.8 V 75 220 500 75 500
µA
I
I(hold)
‡
A
or
B
ports
V
CC =
4
.
5
V
VI = 2 V –75 –180 –500 –75 –500 µ
A
IOZH TDO VCC = 5.5 V,
VO = 2.7 V, OE = 2 V 10 10 10 µA
IOZL TDO VCC = 5.5 V,
VO = 0.5 V, OE = 2 V –10 –10 –10 µA
IOZPU TDO VCC = 0 to 2.1 V,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 ±50 µA
IOZPD TDO VCC = 2.1 V to 0,
VO = 2.7 V or 0.5 V, OE = 0.8 V ±50 ±50 µA
Ioff VCC = 0, VI or VO ≤ 4.5 V ±100 ±100 µA
ICEX Outputs high VCC = 5.5 V, VO = 5.5 V 50 50 50 µA
IO§
A port, TDO VCC = 5.5 V, VO = 2.5 V –50 –110 –200 –50 –200 –50 –200
mA
I
O
§
B port VCC = 5.5 V, VO = 2.5 V –25 –55 –100 –25 –100 –25 –100
mA
Outputs high
VCC
=
5.5 V,
1.7 2.2 2.2 2.2
ICC
Outputs low
VCC
=
5
.
5
V
,
IO = 0,
AorB
p
orts
23 27 27 27
mA
ICC
Outputs
disabled VI = VCC or
GND
A
or
B
orts
1 2 2 2
mA
∆ICC¶VCC = 5.5 V, One input at 3.4 V,
Other inputs at VCC or GND 1.5 1.5 1.5 mA
* On products compliant to MIL-PRF-38535, this parameter does not apply.
†All typical values are at VCC = 5 V.
‡The parameter II(hold) includes the off-state output leakage current.
§Not more than one output should be tested at a time, and the duration of the test should not exceed one second.
¶This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
34 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted) (continued)
PARAMETER
TEST CONDITIONS
TA = 25°C SN54ABTH182646A SN74ABTH182646A
UNIT
PARAMETER
TEST
CONDITIONS
MIN TYP†MAX MIN MAX MIN MAX
UNIT
CiControl inputs VI = 2.5 V or 0.5 V 5 pF
Cio A or B ports VO = 2.5 V or 0.5 V 10 pF
CoTDO VO = 2.5 V or 0.5 V 8 pF
†All typical values are at VCC = 5 V.
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 15)12
SN54ABTH182646A SN74ABTH182646A
UNIT
MIN MAX MIN MAX
UNIT
fclock Clock frequency CLKAB or CLKBA 0 100 0 100 MHz
twPulse duration CLKAB or CLKBA high or low 3 3 ns
tsu Setup time A before CLKAB↑ or B before CLKBA↑3 3 ns
thHold time A after CLKAB↑ or B after CLKBA↑0.5 0.5 ns
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 15)
SN54ABTH182646A SN74ABTH182646A
UNIT
MIN MAX MIN MAX
UNIT
fclock Clock frequency TCK 0 50 0 50 MHz
twPulse duration TCK high or low 8 8 ns
A, B, CLK, DIR, OE, or S before TCK↑6 6
tsu Setup time TDI before TCK↑4.5 4.5 ns
TMS before TCK↑3 3
A, B, CLK, DIR, OE, or S after TCK↑1.5 1.5
thHold time TDI after TCK↑1 1 ns
TMS after TCK↑1.5 1.5
tdDelay time Power up to TCK↑50 50 ns
trRise time VCC power up 1 1 µs
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
35
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (normal mode) (see Figure 15)12
PARAMETER FROM
(INPUT)
TO
(OUTPUT)
VCC = 5 V,
TA = 25°CSN54ABTH182646A SN74ABTH182646A UNIT
(INPUT)
(OUTPUT)
MIN TYP MAX MIN MAX MIN MAX
fmax CLKAB or
CLKBA 100 150 100 100 MHz
tPLH
A
B
1.5 3.5 5.1 1.5 5.8 1.5 5.3
ns
tPHL
A
B
1.5 4.1 5.8 1.5 6.4 1.5 6.1
ns
tPLH
B
A
1.5 3.1 4.7 1.5 5.2 1.5 5
ns
tPHL
B
A
1.5 3.3 5 1.5 5.6 1.5 5.4
ns
tPLH
CLKAB
B
1.5 4.3 6.2 1.5 7 1.5 6.5
ns
tPHL
CLKAB
B
1.5 4.9 7 1.5 8.1 1.5 7.4
ns
tPLH
CLKBA
A
1.5 3.6 5.2 1.5 6.2 1.5 5.9
ns
tPHL
CLKBA
A
1.5 3.8 5.5 1.5 6.5 1.5 6.1
ns
tPLH
SAB
B
1.5 4.4 6.9 1.5 7.6 1.5 7.2
ns
tPHL
SAB
B
1.5 4.8 7.4 1.5 8.3 1.5 7.8
ns
tPLH
SBA
A
1.5 3.8 5.6 1.5 6.8 1.5 6.6
ns
tPHL
SBA
A
1.5 3.9 6 1.5 7.2 1.5 6.8
ns
tPZH
DIR
BorA
1.5 3.9 6.3 1.5 7.5 1.5 7
ns
tPZL
DIR
B
or
A
1.5 4 6.5 1.5 7.7 1.5 7.2
ns
tPZH
OE
BorA
1.5 4.2 6.7 1.5 8.1 1.5 7.4
ns
tPZL
OE
B
or
A
1.5 4.3 6.9 1.5 8.4 1.5 7.6
ns
tPHZ
DIR
BorA
2 5.9 8.8 2 10.3 2 10
ns
tPLZ
DIR
B
or
A
2 4.7 6.9 2 8.7 2 8.1
ns
tPHZ
OE
BorA
2 6 9 2 10.5 2 9.7
ns
tPLZ
OE
B
or
A
2 4.8 7.1 2 8.7 2 7.6
ns
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (test mode) (see Figure 15)
PARAMETER FROM
(INPUT)
TO
(OUTPUT)
VCC = 5 V,
TA = 25°CSN54ABTH182646A SN74ABTH182646A UNIT
(INPUT)
(OUTPUT)
MIN TYP MAX MIN MAX MIN MAX
fmax TCK 50 90 50 50 MHz
tPLH
TCK↓
AorB
2.5 6.1 11 2.5 14.5 2.5 13.1
ns
tPHL
TCK↓
A
or
B
2.5 6.5 10.8 2.5 14 2.5 12.4
ns
tPLH
TCK↓
TDO
2 3.6 5.1 2 7 2 5.6
ns
tPHL
TCK↓
TDO
2 3.7 5.1 2 7 2 5.6
ns
tPZH
TCK↓
AorB
4 7.1 11.5 4 14.5 4 13.4
ns
tPZL
TCK↓
A
or
B
4 7.2 11.8 4 15 4 13.6
ns
tPZH
TCK↓
TDO
2 3.7 5.7 2 7.5 2 6.6
ns
tPZL
TCK↓
TDO
2 3.9 6.2 2 8 2 6.9
ns
tPHZ
TCK↓
AorB
4 8.5 13 4 18 4 15
ns
tPLZ
TCK↓
A
or
B
3 7.2 13.3 3 17.5 3 15
ns
tPHZ
TCK↓
TDO
3 5.1 6.8 3 8 3 7.2
ns
tPLZ
TCK↓
TDO
2.5 4 5.5 2.5 8 2.5 6.3
ns
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
SN54ABTH18646A, SN54ABTH182646A, SN74ABTH18646A, SN74ABTH182646A
SCAN TEST DEVICES WITH
18-BIT TRANSCEIVERS AND REGISTERS
SCBS166D – AUGUST 1993 – REVISED JULY 1996
36 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
1.5 V
th
tsu
From Output
Under Test
CL = 50 pF
LOAD CIRCUIT
S1
7 V
Open
GND
500 Ω
500 Ω
Data Input
Timing Input 1.5 V 3 V
0 V
1.5 V 1.5 V 3 V
0 V
3 V
0 V
1.5 V 1.5 V
tw
Input
(see Note A)
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
VOLTAGE WAVEFORMS
PULSE DURATION
tPLH
tPHL
tPHL
tPLH
VOH
VOH
VOL
VOL
1.5 V 1.5 V 3 V
0 V
1.5 V1.5 V
Input
1.5 V
Output
Control
Output
W aveform 1
S1 at 7 V
(see Note B)
Output
W aveform 2
S1 at Open
(see Note B)
VOL
VOH
tPZL
tPZH
tPLZ
tPHZ
1.5 V
1.5 V
3.5 V
0 V
1.5 V VOL + 0.3 V
1.5 V VOH – 0.3 V
[
0 V
3 V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
Output
Output
tPLH/tPHL
tPLZ/tPZL
tPHZ/tPZH
Open
7 V
Open
TEST S1
NOTES: A. CL includes probe and jig capacitance.
B. W aveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
W aveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR ≤ 10 MHz, ZO = 50 Ω, tr ≤ 2 . 5 n s , tf≤ 2.5 ns.
D. The outputs are measured one at a time with one transition per measurement.
Figure 15. Load Circuit and Voltage Waveforms
PACKAGE OPTION ADDENDUM
www.ti.com 5-Sep-2011
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
5962-9669801QXA ACTIVE CFP HV 68 1 TBD Call TI Call TI
74ABTH182646APMG4 ACTIVE LQFP PM 64 160 Green (RoHS
& no Sb/Br) CU NIPDAU Level-3-260C-168 HR
SN74ABTH182646APM ACTIVE LQFP PM 64 160 Green (RoHS
& no Sb/Br) CU NIPDAU Level-3-260C-168 HR
SN74ABTH18646APM ACTIVE LQFP PM 64 160 Green (RoHS
& no Sb/Br) CU NIPDAU Level-3-260C-168 HR
SN74ABTH18646APMG4 ACTIVE LQFP PM 64 160 Green (RoHS
& no Sb/Br) CU NIPDAU Level-3-260C-168 HR
SNJ54ABTH18646AHV ACTIVE CFP HV 68 1 TBD Call TI N / A for Pkg Type
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 5-Sep-2011
Addendum-Page 2
OTHER QUALIFIED VERSIONS OF SN54ABTH18646A, SN74ABTH18646A :
•Catalog: SN74ABTH18646A
•Military: SN54ABTH18646A
NOTE: Qualified Version Definitions:
•Catalog - TI's standard catalog product
•Military - QML certified for Military and Defense Applications
MECHANICAL DATA
MTQF008A – JANUARY 1995 – REVISED DECEMBER 1996
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PM (S-PQFP-G64) PLASTIC QUAD FLATPACK
4040152/C 11/96
32
17 0,13 NOM
0,25
0,45
0,75
Seating Plane
0,05 MIN
Gage Plane
0,27
33
16
48
1
0,17
49
64
SQ
SQ
10,20
11,80
12,20
9,80
7,50 TYP
1,60 MAX
1,45
1,35
0,08
0,50 M
0,08
0°–7°
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Falls within JEDEC MS-026
D. May also be thermally enhanced plastic with leads connected to the die pads.
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