Question

There are, of course, multiple ways to do this! Here's another approach which also should

execute four times. (Three blanks to fill)
mov ro, #
; an immediate value
;a flag-changing mathematical operation
; a branch statement
Loop
r0, #1
Exit
; DO THINGS
b Loop

Answer 1

mov r0, #4

sub r0, #1

bne Loop

Step-by-step explanation:

In the given assembly code snippet, the objective is to execute a loop four times. Let's break down the solution into three components:

1. `mov r0, #4`: This initializes the register `r0` with the value 4, indicating the loop should run four times.

2. `sub r0, #1`: Subtracts 1 from the value in `r0` during each iteration. This is a typical setup to count down in loops.

3. `bne Loop`: Branches back to the label `Loop` (branch if not equal) as long as the result of the subtraction is not zero. This ensures the loop executes four times before exiting.

This approach efficiently achieves the desired loop behavior, counting down from 4 to 1. The `bne` instruction is crucial for branching until the count becomes zero, facilitating the loop's termination.

Answer 2

The question deals with creating a loop in assembly language that runs four times. To complete this task, set the initial loop counter to 4, decrement it within the loop, and continue looping until the counter reaches zero.

Step-by-step explanation:

The question appears to be related to assembly programming, specifically on how to create a loop that executes four times using assembly language instructions. To achieve this, certain keywords need to be added to the skeleton code given to complete the loop functionality.

The immediate value that needs to be moved into the register r0 is the initial count of the loop, the flag-changing mathematical operation is typically a subtraction to decrement the counter each time the loop iterates, and the branch statement is used to check if the loop should continue or exit.

Here's an example to fill in the blanks:

• mov r0, #4 ; Move the immediate value 4 into r0
• subs r0, r0, #1 ; Subtract 1 from r0 and update the flags
• bne Loop ; Branch to Loop if Zero flag is not set (i.e., r0 is not zero)