How does the interrupt control register change?

September 11, 2019 8:35 am

* Question

* Answer

The interrupt control register must be changed at a location where the interrupt request to the corresponding register does not occur.When an interrupt request is possible, first disable the interrupt and then change the interrupt control register.When changing the interrupt control register after interrupt is disabled, you must pay attention to the instructions used.Change of IR bit.When the IR bit is cleared to “0” (no interrupt request), the IR bit may not be changed to “0” depending on the instruction used, so the IR bit must be cleared to “0” using the MOV instruction.