SN54ACT8999 Datasheet, PDF (1/29 Pages) Texas Instruments – SCAN-PATH SELECTORS WITH 8-BIT BIDIRECTIONAL DATA BUSES SCAN-CONTROLLED IEEE STD 1149.1 (JTAG) TAP MULTIPLEXERS

SN54ACT8999, SN74ACT8999
SCANĆPATH SELECTORS WITH 8ĆBIT BIDIRECTIONAL DATA BUSES
SCANĆCONTROLLED IEEE STD 1149.1 (JTAG) TAP MULTIPLEXERS
SCAS158D − JUNE 1990 − REVISED DECEMBER 1996
D Members of theTexas Instruments
SCOPE  Family of Testability Products
D Compatible With the IEEE Standard 1149.1
(JTAG) Serial Test Bus
D Allow Partitioning of System Scan Paths
D Can Be Cascaded Horizontally or Vertically
D Select One of Four Secondary Scan Paths
to Be Included in a Primary Scan Path
D Provide Communication Between Primary
and Remote Test Bus Controllers
D Include 8-Bit Programmable Binary Counter
to Count or Initiate Interrupt Signals
D Include 8-Bit Identification Bus for Scan
Path Identification
D Inputs Are TTL Compatible
D EPIC  (Enhanced-Performance Implanted
CMOS) 1-µm Process
D Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic
(NT) and Ceramic (JT) 300-mil DIPs
SN54ACT8999 . . . JT PACKAGE
SN74ACT8999 . . . DW OR NT PACKAGE
(TOP VIEW)
DTDI 1
OTMS 2
DCO 3
MCO 4
DTDO 5
DTCK 6
GND 7
DTMS1 8
DTMS2 9
DTMS3 10
DTMS4 11
DTRST 12
TDO 13
TMS 14
28 DCI
27 MCI
26 ID1
25 ID2
24 ID3
23 ID4
22 ID5
21 V_CC
20 ID6
19 ID7
18 ID8
17 TRST
16 TDI
15 TCK
SN54ACT8999 . . . FK PACKAGE
(TOP VIEW)
description
The ’ACT8999 are members of the Texas
Instruments SCOPE testability integrated-
circuit family. This family of components facilitates
testing of complex circuit-board assemblies.
The ’ACT8999 enhance the scan capability of TI’s
SCOPE family by allowing augmentation of a
system’s primary scan path with secondary scan
paths (SSPs), which can be individually selected
by the ’ACT8999 for inclusion in the primary scan
path. The device also provides buffering of test
signals to reduce the need for external logic.
ID1
MCI
DCI
DTDI
OTMS
DCO
MCO
4 3 2 1 28 27 26
5
25
6
24
7
23
8
22
9
21
10
20
11
19
12 13 14 15 16 17 18
ID8
TRST
TDI
TCK
TMS
TDO
DTRST
By loading the proper values into the instruction register and data registers, the user can select one of four
secondary scan paths. This has the effect of shortening the scan path to allow maximum test throughput when
an individual subsystem (board or box) is to be tested. Any of the device’s six data registers or the instruction
register can be placed in the device’s scan path, i.e., placed between test data input (TDI) and test data output
(TDO) for subsequent shift and scan operations.
All operations of the device except counting are synchronous to the test clock (TCK). The 8-bit programmable
up/down counter can be used to count transitions on the device condition input (DCI) and output interrupt signals
via the device condition output (DCO). The device can be configured to count on either the rising or falling edge
of DCI.
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 and EPIC are trademarks of Texas Instruments Incorporated.
PRODUCTION DATA information is 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.
Copyright  1996, Texas Instruments Incorporated
On products compliant to MILĆPRFĆ38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
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