The 'ABT18245A scan test devices with 18-bit bus transceivers are members of the Texas Instruments SCOPE^TM 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 noninverting bus transceivers. 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^TM bus transceivers.