| 摘要 |
PURPOSE:To monitor the fault of a microprocessor itself by using a specific signal used for a initial diagnosis by providing a processor monitoring means which monitors the operation of the microprocessor based on the specific signal used for the initial diagnosis after the microprocessor is released from a rest state. CONSTITUTION:The microprocessor (MPU) 11 of an initial diagnosing system is released from a reset state when RESET signal changes to 'H' after the signal once becomes 'L' on a bus signal line (1) after a supply voltage Vcc is applied to the MPU 11. Then the LSI constitution the MPU 11 is actuated after internal actuating time (a) and the RESET signal is simultaneously inputted to an address discrimination and timer circuits 12a and 12b. When the MPU 11 is actuated, an address strobe signal AS becomes 'L' and access is performed. Then fetching operations by which a specific address is read out from a reset vector area and fetched to the stack pointer SP of the MPU 11 are performed and the address of the bus cycle is recognized in the beginning of the initial diagnosis. |
