| 摘要 |
PROBLEM TO BE SOLVED: To prevent a microprocessor to be tested from deteriorating in performance by providing three registers in the periphery of the microprocessor, supplying a random test pattern to the microprocessor, and compressing and comparing the response output of the microprocessor with a signature which has be previously calculated and prepared. SOLUTION: The added registers TCR22, LFSR24 and MISR26 are used in a test mode. Multiplexers 32 and 34 are used to switch signal paths as to those added registers between the test mode and a normal mode. Further, the register TCR22 supplies the operation code of an instruction of the microprocessor in the test mode. The register LFSR24 is used to generate random test data and the register MISR26 is used to compress the test response. |
