| 摘要 |
PROBLEM TO BE SOLVED: To prevent runaway of a CPU since the possibility of the runaway of the CPU becomes higher, when a register to hold important information for the CPU is rewritten to hold misinformation due to disturbance noise, etc. SOLUTION: The microcomputer is provided with an original register 2 for storing the important information in the CPU and a copy register 3 to hold the information of the original register 2 of the previous one cycle. When a write probe signal S8 is inactive, an abnormality detection signal S9 becomes active, when the values of data output S4 and copy register output S5 are different, and the output S5 of the copy register 3 is outputted as selected input data S13. Thus, abnormal rewrite of the register is prevented by rewriting the original register 2 with the value of the copy register 3. |
