* Question
| What are the two methods for clearing interrupt requests? |
* Answer
| (1) Prefetch of interrupt vector The interrupt vector is an address information, and the acquisition of the address operand will generate an interrupt acknowledge signal to clear the interrupt request.Before exiting the interrupt service routine, the ACKK bit writes l to prevent false interrupts due to noise interference, and setting ACKK will not affect the subsequent transmission of other keyboard interrupt pin signals.Software clearing causes all pins that cause an interrupt to go back high, that is, all pins that cause an interrupt return to high level will clear the keyboard interrupt request, as long as any pin that allows the interrupt is still low., the keyboard interrupt remains set.However, if MODEK=1, falling edge and low level trigger, the interrupt vector prefetch or software clear and all pins that allow the keyboard interrupt function are returned to high level to clear the keyboard interrupt. |
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