| 摘要 |
PURPOSE:To start a normal operation of a microcomputer by providing a means which detects a runaway state of a microprogram with a program counter and initializing the microprogram whan the program is decided to be in the runaway state. CONSTITUTION:In an execution mode of a main program, a counter 3 and a register 4 are first initialized. Then the main processing is executed after the counter 3 is counted up by 1. Then the counter 3 is also counted up by 1 when a series of processings are through. If a trouble occurs while the main program is processed, the processing is discontinued. Then the value of the counter 3 is kept at the same state as that obtained when the value of the counter 3 is set to the register 4. When an interruption signal A is produced from a timer circuit 1, the procedure proceeds to an interruption program. Then the value of the counter 3 is compared with the value of the register 4 based on the contents of a coincidence detecting signal D. When the coincidence is obtained from said comparison, a runaway state is decided. Thus the initialization is carried out to ensure a normal start of operation with a microcomputer. |
