Question

Interrupt Enable instruction is

• A. DI
• B. EI
• C. EPI
• D. EAI

Answer 1

The correct option is B EI

Interrupt enable instruction is EI.

The interrupt enable flip-flop is set and all interrupts are enabled following the execution of next instruction followed by EI. No flags are affected. After a system reset, the interrupt enable flip-flop is reset, thus disabling the interrupts. This instruction is necessary to enable the interrupts again.