| 摘要 |
PROBLEM TO BE SOLVED: To provide a self-check circuit for a microcomputer with which a check for detecting a fault can be performed by detecting a microcode which can not be extracted by an ordinary instruction and operating a constitutive logic element to be operated only by this microcode which can not be extracted by the ordinary instruction. SOLUTION: The microcode, which can not be extracted by the ordinary instruction defined in the microcomputer, is detected by a on-used microcode detecting circuit 105 and a decoder judging circuit 106 judges whether this detected microcode can be outputted from an instruction decoder 104 or not. As a result, a new instruction 7 is generated from the microcode, with which it is judged outputting is possible, and outputted from the instruction decoder 104 and concerning the microcode, with which it is judged outputting is impossible, the microcode is outputted as it is. Then, the results of executing these microcodes by respective function blocks 110 are outputted from an output port 111. |
