Question $1$ options:

The following program implements a stack that grows up toward low memory addresses as items are pushed, and the stack pointer points to the top item on the stack.

$$AREA prog, CODE, READWRITE

$$ ENTRY

$$LDR SP$,=$STACK

$$MOV r$0,$ #$0$x$11$

$$MOV r$1,$ #$0$x$22$

PUSH$\_$R$0$ instruction$\_1$

PUSH$\_$R$1$instruction$\_2$

POP$\_$R$0$instruction$\_3$

POP$\_$R$1$instruction$\_4$

Loop B Loop

$$ space $32$

STACK DCD $0$x$0$

$$ space $32$

$$END

Using ONLY LDR$/$STR instructions:

$-$Write one instruction $($instruction$\_1)$ to push the value of R$0$ onto the stack.

$-$ Write one instruction $($instruction$\_2)$ to push the value of R$1$onto the stack.

$-$ Write one instruction $($instruction$\_3)$ to pop from the stack a$$value and to save it in R$0.$

$-$ Write one instruction $($instruction$\_4)$ to pop from the stack a$$value and to save it in R$1.$

Make sure that the values of R$0$ and R$1$ are swapped after these operations.

What are the $4$ instructions you used?

Write your answer $($i$.$e$.,$ the $4$ instructions$)$ in TWO parts, the mnemonic in a box and ALL operands in another box.

To facilitate automatic marking,

$-$ Use CAPITAL letters ONLY$--$except $0$x$,$ make it a small letter.

$-$ Do NOT leave ANY spaces between operands.

The mnemonic of the $1$st instruction is: $\_\_\_\_$

The operands of the $1$st instruction are: $\_\_\_\_.$

The mnemonic of the $2$nd instruction is: $\_\_\_\_$

The operands of the $2$nd instruction are: $\_\_\_\_.$

The mnemonic of the $3$rd instruction is: $\_\_\_\_$

The operands of the $3$rd$$instruction are: $\_\_\_\_.$

The mnemonic of the $4$th instruction is: $\_\_\_\_$

The operands of the $4$th instruction are: $\_\_\_\_.$

How many elements can be pushed onto this stack? $\_\_\_\_$