SN74ABT8952DWR

Specialty Logic Overview

The SN74ABT8952DWR is a scan test device with octal registered bus transceivers from the Texas Instruments SCOPE family. It supports IEEE Standard 1149.1-1990 boundary scan via a 4-wire TAP interface. The device operates on a single VCC supply between 4.5 V and 5.5 V, with an operating temperature range of -40°C to +85°C. It utilizes BiCMOS technology for reduced power dissipation.

Specialty Logic Feature Summary

• Integrates octal registered bus transceivers with dedicated IEEE 1149.1-1990 compliant test circuitry.
• Features a 38-bit boundary-scan register and an 11-bit boundary-control register for flexible testing.
• Supports parallel-signature analysis and pseudo-random pattern generation through the TAP controller.

Specialty Logic Applications

• Boundary-scan testing of complex circuit-board assemblies
• Self-test operations on boundary-test cells
• Parallel-signature analysis at inputs with masking options

Specialty Logic Procurement Notes

Verify the specific package variant (DW) against the required footprint. Confirm that the design accommodates the four dedicated test pins (TDI, TDO, TMS, TCK). Ensure the system logic correctly handles the internal pullups on TDI and TMS when these pins are left unconnected in normal operation modes.

Specialty Logic Selection Notes

Select this component when board-level testing requires integrated boundary-scan capabilities alongside standard octal registered bus transceiver functions. It serves as a functional equivalent to the 'BCT2952 and 'ABT2952 in normal mode while providing additional SCOPE instruction set support for manufacturing test.

Specialty Logic Part Context

This device belongs to the Texas Instruments SCOPE family of testability products. It is designed to facilitate the testing of complex assemblies by integrating test access port functionality directly with the data bus transceiver logic, eliminating the need for separate boundary-scan controllers.

Specialty Logic Replacement Considerations

The datasheet notes functional equivalence to the 'BCT2952 and 'ABT2952 in normal-function mode. Verify pinout compatibility and instruction set support before substitution.

Specialty Logic FAQ

How does the device handle TDI and TMS if they are left unconnected?

Internal pullup resistors force both TDI and TMS to a high level if they are left unconnected or open-circuited due to board defects.

What happens to the normal logic function when the TAP is enabled?

In test mode, the normal operation of the registered bus transceivers is inhibited to allow observation and control of the I/O boundary. In normal mode, activating the TAP does not affect functional operation.