>That's why I did move the result from the
>MAC0ACCx registers to variables in the DATA space, and watch
>these variables. But these variables are always zero too :-(

MAC0ACC3 should be 0 and MAC0ACC2 should be 03 with the values you are using.

Sometimes there can be bad chip batches, but you tried a 122 and a 123 and the
odds that those two would exhibit the same problem would be small, as far as I
know. Of course, for all I know the 123 is just a 122 in a different package
and they might be from the same batch.

It's probably not something to do with external hardware as the multiplier is
completely internal.

It's not an SFR watch window problem since you're reading them into low RAM as
well and they confirm that it's 0. The MAC status seems to read fine and it
also says it's 0.

Does the IDE have a simulator mode? If so, does that work?

I wouldn't think it has anything to do with any JTAG weirdness as other stuff
seems to be coming through just fine.

I'm stumped. Hopefully Silicon Labs will be able to shine some light on what is
going on.

Hi Gary,

> MAC0ACC3 should be 0 and MAC0ACC2 should be 03 with the values you are using.

that's correct.

> Does the IDE have a simulator mode? If so, does that work?

No, there is no simulator mode.
 
> I wouldn't think it has anything to do with any JTAG weirdness as other stuff seems to be coming through just fine.

agreed. Everything else is working fine in these chips.
There have never been any problems with the JTAG interface.
 
Michael