68000 assembler in OS9

Hi all,

I'm tinkering with 68000 assembler programming under OS9/68000 V2.4.

I think I read somewhere that the 68000 CPU cannot access data on odd
bytes. If that's so, how does one access something like an IDE card,
whose registers are sequential bytes in the memory map, in my case the
port is 0x00F00300 to 0x00F0030F.

For example,

IDE Data is at 0x00F00300
IDE Error reg is 0x00F00301
IDE Status reg is 0x00F00307

etc....
If I load A3 with the port base address, and D0 with the value to be
written, like this:

move.l #$0F00300,a3
move.b 7(a3),d0 ;get the drive status
move.b #$EC,d0
move.b d0,7(a3) ;send Identify Drive command

will that be a legal instruction?

I need to be careful, since, the way I read it, the IDE drive will
begin it's command phase as soon as the command reg 7(a3) is written
to. If the 68000 always writes a word value, I'll need a different
approach. Suggestions, anyone?

Regards,Bob Devries
Dalby, QLD, Australia
.

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