There is a timing bug in the "regular" PICMASTER pod that causes problems
with table reads and writes. I had to move to the "CE" version of the pod.
That could be part of your problem.

Douglas Wood
Software Engineer
dbwood@kc.rr.com

Home of the EPICIS Development System for the PIC and SX
http://epicis.piclist.com

----- Original Message -----
From: "Andrew E. Kalman" <aek@PUMPKININC.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Sunday, September 30, 2001 10:43 PM
Subject: [PIC]: MPLAB + 17C756 + Read External Memory Crash


> Hi All.
>
> I've got a board working with the 17C756 in external microcontroller
> mode. I've verified that it can read and write to external RAM just
> fine with my emulator (PICMASTER). I've also verified that if I try
> to write to an area that has no RAM, sure enough, when I read it
> back, I get 0xFFFF.
>
> But any attempt to read external memory (i.e. memory above 0x4000) in
> MPLAB 5.20 (e.g. via the Modify Window, with Memory Area=Program and
> "Read" button) results in MPLAB crashes. I've set the PICMASTER's
> Configuration to "Extended Microcontroller" and the Memory to
> "Off-Chip Memory ... from Target Board".
>
> I know the new, non-0xFFF data is out in RAM, because I read it back
> via a function and assign it to a local variable, which is watch in a
> Watch Window. But I can't seem to see it directly, neither through
> the Modify Window nor through the Program Mmeory Window.  If I use
> the Modify window to _write_ to program memory (e.g. all 0's, a nop),
> the Program Memory window shows the nop, but it seems to be "fake" in
> that a read of the same location causes an MPLAB crash, etc.
>
> All help and suggestions appreciated. The 17C756 circuit in question
> is in Application Guide AG-5 on our website.
>
> Thanks,
> --
>
>   ______________________________________
> Andrew E. Kalman, Ph.D.
>
>
> Salvo(TM), The RTOS that runs in tiny places(TM)
> Pumpkin, Inc.
> 750 Naples Street
> San Francisco, CA 94112
> tel: (415) 584-6360
> fax: (415) 585-7948
> web: http://www.pumpkininc.com
> email: aek@pumpkininc.com
>
> --
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>
>

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