Question $1(10$ points$)$

Convert the GCD algorithm given in this flowchart into ARM assembly using ONLY $4$ instructions, where any instructions can be conditional. The only instructions you need are CMP$,$ B$,$ and SUB. To facilitate the automatic marking, always convert the "Yes" branch of the flow chart before the $"$No$"$ branch. AREA prog, CODE, READWRITE

ENTRY

MOV RO$,\backslash$#$51$

MOV R$1,\backslash$#$34$

GCD instruction$-1$

instruction$-2$

instruction$-3$

instruction$-4$

Loop B Loop

END

Test your code by assigning various values to R $0$ and R $1.$

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: $.$

Encode the $2$nd instruction to ARM machine language code.

$\backslash (0$ x $\backslash )\backslash (0$ x $\backslash )0$x $0$x $0$x $\backslash (0$ x $\backslash )\backslash (0$ x $\backslash )\backslash (0$ x $\backslash )$ Encode the $2$nd instruction to ARM machine language code.

$0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_0$x$\_\_\_.$ A

A

A

A

A

A

A

A A

A

A A A A A

A