The ABT18245 scan test devices with 18-bit bus transceivers are members of the Texas Instruments SCOPE testability integratedcircuit 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 bus transceivers.
Data flow is controlled by the direction-control (DIR) and output-enable (OE) inputs. Data transmission is allowed from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at DIR. OE can be used to disable the device so that the buses are effectively isolated. In the test mode, the normal operation of the SCOPE bus transceivers is inhibited and the test circuitry is enabled to observe and control the input/output (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.
Members of the Texas Instruments SCOPE ™ Family of Testability Products
Members of the Texas Instruments Widebus™ Family
Compatible With the IEEE Standard 1149.1-1990 (JTAG) Test Access Port and Boundary-Scan Architecture
SCOPE ™ Instruction Set
IEEE Standard 1149.1-1990 Required Instructions, CLAMP and HIGHZ
Parallel-Signature Analysis at Inputs
Pseudo-Random Pattern Generation From Outputs
Sample Inputs/Toggle Outputs
Binary Count From Outputs
State-of-the-Art EPIC-ΙΙB™ BiCMOS Design Significantly Reduces Power Dissipation
Packaged in Plastic Shrink Small-Outline (DL) and Thin Shrink Small-Outline (DGG) Packages and 380-mil Fine-Pitch Ceramic Flat (WD) Packages