| 摘要 |
<p>An apparatus and method test the functionality of a microprocessor (100). The microprocessor (100) performs a two-phase self-test. In the first phase, the microprocessor (100) sequentially executes every micro-instruction stored in a micro-instruction ROM (156), without allowing any micro-instruction jumps. Micro-instruction jumps are inhibited by ignoring a next address. A number of the first micro-instructions substantially initialize the microprocessor circuitry to a known state so that outputs (131, 132) generated by the microprocessor are deterministic. During this first phase, a number of output pins are driven so that an optional external test unit can monitor the output pins and compare the output values against expected values. In addition, cyclical redundancy registers (141, 157) monitor other circuits within the microprocessor. After successful completion of the first phase, the results of the first phase are reported and the second phase begins. The second phase comprises comprehensive micro-diagnostic testing. The second phase of the self test ends with the reporting of the results of the micro-diagnostic tests.</p> |
