On the testing of microprogrammed processor

A testing procedure is given for a microprogrammed processor. The conventional procedure to generate test vectors is used instead of C-testability for the bit-slice microprocessor. The minimal complete test sequences are calculated for the micro-sequencer and the ALU, and stored in the micro-memory. Micro-memory is implemented by an electrically erasable PLA which has the capability to test itself using a universal test set. A one-bit wide processor section is assumed. However, the method can be extended to a processor of any word length. The tests for the microsequencer and the ALU are applied from the micromemory. The response is compared against precalculated signature stored in the system memory. A parity bit is generated to indicate a fault