User Guide
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Restore the contents of the Program Counter (PC) (analogous to the
RET instruction)
•
Signal an I/O device that the interrupt routine is completed. The RETI
instruction also facilitates the nesting of interrupts, allowing higher
priority devices to temporarily suspend service of lower priority
service routines. However, this instruction does not enable interrupts
that were disabled when the interrupt routine was entered. Before
doing the
RETI instruction, the enable interrupt instruction (EI)
should be executed to allow recognition of interrupts after completion
of the current service routine.
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