> I avoid the Parallax set of instructions and warn beginners to stay away
> even if they are familiar with 8051 operations.  I avoid it because
> registers and Status register flags can get changed inadvertently without
> the user neccessarily knowing it.
>
> On these points, what do other people think?

I agree. That was my first reaction when I got the Scenix stuff (my
first contact with Parallax tools).
I don't have a problem with them being there, but I would
really like to be able to turn them off in the assembler or have
the option to have them flagged as warnings or at least expanded in
the listing file.

It also seemed rather odd to have a micro that has a small
instruction set as one of its benefits and then add lots
more instructions.

Two things made me most nervous about the idea. The hidden
register/flag changes you mention and the increased likelyhood of
typing related bugs. For example, leaving a '!' off a Scenix
instruction would be an error caught by the assembler in a native
assembler, but would produce a different instruction in the extended
instruction set. I know which I prefer.

Steve.



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Steve Baldwin                Electronic Product Design
TLA Microsystems Ltd         Microcontroller Specialists
PO Box 15-680, New Lynn      http://www.tla.co.nz
Auckland, New Zealand        ph  +64 9 820-2221
email: steveb@tla.co.nz      fax +64 9 820-1929
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