| 摘要 |
PURPOSE:To perform efficiently the operation processing of an interrupting circuit which cannot be masked by a program, by providing a delay means, which delays an interrupting operation for a certain time, to prevent the processing before the interruption processing from being left broken. CONSTITUTION:An interruption signal (a) is inputted to a chattering preventing circuit 1 from the outside of an integrated circuit of a microcomputer to eliminate the chattering, and an output stable to an input variance is inputted to a delay circuit 2 and an exclusive OR circuit 3, and the output of the circuit 2 is applied to the other input of the circuit 3. An FF4 is set by the output of the circuit 3, and information indicating that the interruption signal (a) is changed is stored, and a timer 5 starts counting by the output of the FF4. An output (b) of the FF4 is outputted as a status flag, and an interrupting operation output (c) is outputted from the timer after the elapse of a prescribed time, and the FF4 is reset, and the operation can be checked by the output (b) before the interrupting operation, and thus, the operation of an interrupting circuit is ensured. |
