| 摘要 |
PROBLEM TO BE SOLVED: To execute inspection with a small pin without the need of test ROM in a microcomputer. SOLUTION: An instruction transfer register 1 receiving instruction codes inputted from outside in series at the time of a test and transferring them at every number of bits, which is similar to inner data bus width, a transfer pointer 2 which is increased whenever an instruction transfer register 1 transfers the instruction code 15 to RAM 3, the execution pointer 4 of RAM 3 executing an increment operation independent of execution PC of CPU 6 and a standby control circuit 5 restricting the loading of the instruction code to RAM 3 on the instruction buffer 7 of CPU 6 are installed. Since the test against whole memory spaces which a microcomputer has is realized without being affected by the actual address of RAM 3, test ROM is not required and inspection with a small pin is realized. |
