LDR R$0,$ GPIO PORTA$\_$DIR$\_$R

MOV R$1,$ #$0$xFO

STR R$1,[$R$0]$

a$)$ This procedure enables the digital output for port $A.$

b$)$ This procedure enables the digital output for port A pins $7,6,5$ and $4$ as outputs and $3,2,1$ and $0$ as inputs.

c$)$ This procedure enables the digital output for port A pins $7,6,5$ and $4$ as inputs and $3,2,1$ and $0$ as outputs.

d$)$ This procedure disables the digital output for port $A.$