NG80960JD

The 80960Jx incorporates numerous features which enhance the user's ability to test both the processor and the system to which it is attached. These features include ONCE (On-Circuit Emulation) mode and Boundary Scan (JTAG).

The 80960Jx provides testability features compatible with IEEE Standard Test Access Port and Boundary Scan Architecture (IEEE Std. 1149.1).

One of the boundary scan instructions, HIGHZ, forces the processor to float all its output pins (ONCE mode). ONCE mode can also be initiated at reset without using the boundary scan mechanism.

ONCE mode is useful for board-level testing. This feature allows a mounted 80960JD to electrically "remove" itself from a circuit board. This allows for system-level testing where a remote tester - such as an in-circuit emulator - can exercise the processor system.

The provided test logic does not interfere with component or circuit board behavior and ensures that components function correctly, connections between various components are correct, and various components interact correctly on the printed circuit board.

The JTAG Boundary Scan feature is an attractive alternative to conventional "bed-of-nails" testing. It can examine connections which might otherwise be
inaccessible to a test system.