Q3
Single choice
An interrupt handler contains the following instruction sequence at the end. The purpose of these instructions is to clear the interrupt request in the interrupt controller and then safely re-enable interrupts.
STR r0, [r1] ; write to interrupt controller register to clear interrupt request
<x>
CPSIE i ; re-enable IRQ interrupts
Which of the following instructions should be placed at position <x> in order to ensure that the interrupt controller sees the write before interrupts are re-enabled?