| 摘要 |
PURPOSE:To attain a microcomputer system with high reliability by using a detection circuit for discordance between an output latch and the terminal value and two microcomputers having the same program. CONSTITUTION:The output is inhibited to an output driver 13 by the signal value of a mode control signal line 15, and the signal impressed to a mode selection line is given to the line 15. Therefore the driver 13 becomes active in an execution mode of a microcomputer and then inactive in a fault detection mode. While a discordance detecting circuit 14 compares the bit values corresponding to an output latch 5 and an output terminal 8 with each other in a fault detection mode. If the discordance is detected, a fault detection signal is delivered to a malfunction detecting signal line via a discordance signal line 16. Thus it is possible to attain a microcomputer system of high reliability with two microcomputers having the same program. |
