Question $3$

$($a$)$ The STM$32$L$031$s CPU core is an Arm Cortex M$0+.$ It does not allow data

transfers directly from one memory location to another. If a symbol $$X$$ is declared as shown below, write the Arm$-$Thumb $($assembler$)$ instructions necessary to read the val ue stored at X into register R$0$

AREA DATA

X DCD $10$

$[4$ marks$]$

$($b$)$ The MOVS instruction provides an efficient way of loading a limited range of

values into a Cortex M$0+$ register. What range of values is allowed?

$[2$ marks$]$