Using a single test described in 4.8.1, we can test for faults in several different signals, but typically not all of them. Describe a series of tests to look for this fault in all Mux outputs (every output bit from each of the ive Muxes). Try to do this with as few single-instruction tests as possible.

Problems 4.8.1

Let us assume that processor testing is done by filling the PC, registers, and data and instruction memories with some values (you can choose which values), letting a single instruction execute, then reading the PC, memories, and registers. These values are then examined to determine if a particular fault is present. Can you design a test (values for PC, memories, and registers) that would determine if there is a stuck-at-0 fault on this signal?

The following problems refer to the following fault:

Fault a. Stuck-at-0 b. Becomes O if RegDst control signal is 0, no fault otherwise