Members of the Texas Instruments

SCOPE? Family of Testability Products

Octal Test-Integrated Circuits

Functionally Equivalent to ’F244 and

’BCT244 in the Normal-Function Mode

Compatible With the IEEE Standard

1149.1-1990 (JTAG) Test Access Port and

Boundary-Scan Architecture

Test Operation Synchronous to Test

Access Port (TAP)

Implement Optional Test Reset Signal by

Recognizing a Double-High-Level Voltage

(10 V) on TMS Pin

SCOPE? Instruction Set

? IEEE Standard 1149.1-1990 Required

Instructions, Optional INTEST, CLAMP

and HIGHZ

? Parallel-Signature Analysis at Inputs

? Pseudo-Random Pattern Generation

From Outputs

? Sample Inputs/Toggle Outputs

Package Options Include Plastic

Small-Outline (DW) Packages, Ceramic

Chip Carriers (FK), and Standard Plastic

and Ceramic 300-mil DIPs (JT, NT)

description

The ’BCT8244A scan test devices with octal

buffers are members of the Texas 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 functionally equivalent to the ’F244 and ’BCT244 octal buffers. The test

circuitry can be activated by the TAP to take snapshot samples of the data appearing at the device terminals

or to perform a self test on the boundary-test cells. Activating the TAP in normal mode does not affect the

functional operation of the SCOPE? octal buffers.

In the test mode, the normal operation of the SCOPE? octal buffers is inhibited and the test circuitry is enabled

to observe and control the I/O boundary of the device. When enabled, the test circuitry can perform

boundary-scan test operations, as described in IEEE Standard 1149.1-1990.