[Solved] Examine this ARM assembly code snippet: MOV R1, #10 WFI MOV R2, #20What is the likely issue with this code? | ARM Architecture

ARM Architecture - Power Modes

Examine this ARM assembly code snippet:

    MOV R1, #10
    WFI
    MOV R2, #20

What is the likely issue with this code?

AThere is no issue; the code is valid

BWFI cannot be used between MOV instructions

CMOV instructions cannot use immediate values

DWFI must be preceded by an interrupt enable instruction

Step-by-Step Solution

Solution:

Step 1: Understand WFI behavior
The WFI instruction puts the processor into sleep mode until an interrupt or event occurs.
Step 2: Check interrupt enable status
If interrupts are not enabled before WFI, the processor may never wake up, causing a deadlock.
Step 3: Analyze the code snippet
The snippet does not show any interrupt enable instruction before WFI, which is necessary for proper wake-up.
Final Answer:
WFI must be preceded by an interrupt enable instruction -> Option D
Quick Check:
WFI requires interrupts enabled to wake up [OK]

Quick Trick: Enable interrupts before WFI to avoid deadlock [OK]

Common Mistakes:

Master "Power Modes" in ARM Architecture

9 interactive learning modes - each teaches the same concept differently

More ARM Architecture Quizzes

Examine this ARM assembly code snippet: