John Coppens wrote:
>=20
> Hello all...
>=20
> As mentioned in my mail, I submitted the strange behaviour I
> experienced with mplab x to the Microchip bug list, and got as answer:
>=20
> <paraphrased>
> We believe that this is due to the read-modify-write nature of the bsf
> instructions. You should keep an image and update the image
> </paraphrased> (...and closed the bug)
>=20
> If I understand the RMW behaviour, then the possible problems are due
> to either capacitive (or other) loading of the outputs, or having some
> internal peripheral enabled which could cause the same loading.
>=20
> Is there any way this could explain my problem? I even tried the
> 'image' method to update port A, and the mplab X simulator _still_
> doesn't show any change to the port A output.

Microchip's reply sounds like a cop-out to me.  RMW potentially affects
actual hardware, in ways that depend on the hardware.  A simulator can't
take that into account (ok, unless you're using something like Proteus with
a SPICE model of the attached hardware).  RMW should not be the explanation
for what you see in the simulator.

I suspect that Microchip didn't understand what you were getting at (or
didn't take the time to understand...).


Cheers,
David Meiklejohn
www.gooligum.com.au


--=20
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