| 摘要 |
PURPOSE:To detect the runaway of a CPU while it has an access to a memory means with a watchdog timer circuit which is used to a monitor controller. CONSTITUTION:When a CPU 2 has no access to 1 storage means 4 even in a normal operation state of the CPU 2, a watchdog timer circuit 3 is repetitively reset before the set time is counted with the reset commands impressed periodically from the CPU 2 and then counts the set time if the reset commands received from the CPU 2 are delayed and transmits an alarm to show the runaway of the CPU 2. Meanwhile 8 data collator means 5 transmits the reset signals to the circuit 3 every time a fact that the state information on the means 4 read out by the CPU 2 with an access given to the means 4 can receive an access is detected. |
