| 摘要 |
<p>PURPOSE:To hold a software in common between conventional machines, by shifting a mode to a HALT mode by executing an interruption standby instruction after an interruption approval instruction has been executed, and shifting it to a STOP mode by the interruption standby instruction after all interruption inuibiting instructions is executed. CONSTITUTION:When shifting a regular operation mode to an HALT mode, an interruption approval instruction for shifting it to the HALT mode is executed so as to obtain a state thar an interrupting instruction can be inputted through an external interruption input terminal 14, an interruption standby signal is set to an active state by executing the following interruption holding instruction, and an HALT flag 11 is set. As a result, the HALT signal is set to an active state, and supply of a clock to an interruption detecting circuit 13, etc. is stopped. The interruption standby signal is also supplied to one input terminal of an AND gate 16 connected to a STOP flag 15, but the other input terminal is connected to an output terminal of a STOP detecting circuit 17, its output attains an active level only when the interruption inhibiting instruction is executed, and the STOP flag 15 attains a reset state.</p> |
