[TI-H] Re: Hardware
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[TI-H] Re: Hardware
On Tue, 17 Jul 2001, Nick wrote:
> but remember the instruction order in the cpu itself is to, from on intel
> cpu's.
>
> [inst.][to][from]
>
If you are refering to the opcodes, the intel move instruction is a 3 byte
sequence (for a 16 bit immediate value into a 16 bit register).
mov ax, 4545
is
B8 45 45
The 'B8' describes a 16 bit move to AX, '45 45' is the value. The
instruction and destination are not really seperate pieces of information.
Rather than
Move ToHere FromHere
its
MoveToHere FromHere
If you want to break the instruction down to its bits it would make sense
to break up the instruction and the destination, just depends on how you
want to look at it really. At the microcode level I'd be suprised to see
'B8' and 'BB' (immediat move to ax and bx, respectivly) handled as
seperate classes of the 'mov' instruction, rather than just an operation.
But then I've never seen the intel microcode, so who knows.
Either way, the 'to' is coming before the 'from'. 'Before' in the sense
that the 'to' information is found at a lower memory address.
DK
References: