At 21.02 07-03-1997 +0000, you wrote:
>
>Here's some code from a PIC16C64 project using PSP.  I tried
>including it in the message, but it didn't format very well, so I'm
>attaching it.  This was written with ByteCraft MPC.
>
>Hope you find it useful ...
>
>
>Randy Rasa
>rrasa@sky.net

Thank you for your code. My first impression is that it looks pretty much
like mine.  I'll study it more careful when I get back to work and can
compare it with what I've tried, to see if there are any significant
differences.
I don't think the problem is with the interrupt service routine, the problem
is that the PSPIF bit does not get set in the first place despite low pulses
on !CS and !WR. I'm trying to interface the PIC to a 80C85 processor, !CS is
900 ns and !WR is 450 ns well within !CS.
I've had a timer running, it worked fine and the interrupt service routine
too, pulsing an output pin.

Andy wrote:
>Nobody replied before because Microchip did a poor job of implementing the
>PSP, and it's not especially useful from what I understand.
>
>Hook up a FIFO and let the PIC use that to get data quickly.  That's what I
>did.
Maybe Andy is right, I just don't hope it means that it don't work at all
because the PSP is an essential feature in my design.
The PIC is going to replace an obsolete multi communications part and for
that it is ideal, it has all the functions I need and more but my board is a
bit crowded and there is hardly space for any more circuitry.

Thank you for your inputs.  Do you, or anybody else, have an explanation for
the missing PSP interrupt flag, PSPIF in PIR1?

Regards
Michael