If initially the ColdFire registers contain d0 0xFFFEDCBF d

If, initially, the ColdFire registers contain: d0 = 0xFFFEDCBF d1 = 0x12348765 a0 = 0x8070A0B0 what will be the contents of these registers

(a) following the instructions,

move.b %d1,%d0

move.w %d0,%d1

(b) following the instructions (start fresh from the initial conditions. i.e. instructions in (a) are not executed before the following),

movea.w %d1,%a0 Could we use “move.w” instead? Why or why not?

move.b %a0,%d1 Is this a legitimate instruction?

Solution

a)

In this case the move Instruction works Directly on the data Regisrters.

move.b Copies a byte from source to destination.

move.w Copies a word from source to destination

So Initially data register contains: d0 = 0xFFFEDCBF d1 = 0x12348765.

b)

movea.w %d1,%a0 Could we use “move.w” instead? Why or why not?

Instead of movea.w %d1,%a0 move.w cannot be used.

Because for move.w the operation format is as below.

move.w <Source> <Destination>

and this Destination cannot be an A register, an immediate operand or a PC-relative address.Where as this must be a data alterable Node.

move.b %a0,%d1 Is this a legitimate instruction?

move.b %a0,%d1 --> This is a legitimate instruction. As for move souce can be a data register and/or an address register. There is no restriction on the source.