SPRUJ55D September 2023 – July 2025 AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1
During the Compare Mismatch Test, the number of test patterns is equal to the number of bus signals on the checker CPU to be monitored. There are a total of 6 signals being monitored on the checker CPU's level 2 interface and hence it takes 6 test patterns for the mismatch test. The mismatch test will take a total of 6 cycles to complete. An all 0's test vector is applied to the CCM-R5F’s but with one bit flipped starting from signal position 0. The un-equal vector will cause the CCM-R5F to expect a compare mismatch at signal position 0, if the CCM-R5F logic is working correctly. If, however, the CCM-R5F logic reports a compare match, the self-test error flag is set, the self-test error signal is asserted, and the Compare Mismatch Test is terminated.
This Compare Mismatch Test algorithm repeats in a domino fashion with the next signal position flipped while forcing all other signals to logic level 0. This sequence is repeated until every inactivity monitor signal position is verified on the checker CPU .
Table 7-17 shows the sequence of Compare Mismatch Test. There is no error signal sent to ESM if the expected errors are seen with each pattern.
| Signal Position | ||||||
|---|---|---|---|---|---|---|
| 5 | 4 | 3 | 2 | 1 | 0 | Cycle |
| 0 | 0 | 0 | 0 | 0 | 1 | 0 |
| 0 | 0 | 0 | 0 | 1 | 0 | 1 |
| 0 | 0 | 0 | 1 | 0 | 0 | 2 |
| 0 | 0 | 1 | 0 | 0 | 0 | 3 |
| 0 | 1 | 0 | 0 | 0 | 0 | 4 |
| 1 | 0 | 0 | 0 | 0 | 0 | 5 |