gnupic: Re: PIC Emulator...
Subject:
Re: PIC Emulator...
From:
Scott Dattalo ####@####.####
Date:
1 Mar 2000 12:09:34 -0000
Message-Id: <Pine.LNX.4.05.10003010530030.17422-100000@tempest.blackhat.net>
On Wed, 1 Mar 2000, Axel Wachtler wrote:
> Matt wrote:
> > I have been inspired (thanks Ray) to employ my C/C++ skills in
> writing
> > an emulator to tie the new pinout stimulator to the parallel port...
> > this would be excellent for creating a really really easy ICE... you
> > couldn't get simpler than putting wires on connectors, on your working
>
> > hardware (excluding PIC)..
>
> I'd just the same idea when I saw the stimulus capabilties in gpsim.
> But we'll need external hardware for the port to get more than 8 outputs
>
> and 4 inputs, at least if a port is bidirectional we'll need a tristate
> buffer.
>
> Does anybody know a PLD which can be programmed in system, (EEPROM- |
> FLASH-able)
> to have the possibility to reconfigure the PORT-Layout. Using a PIC16x84
> directly would be
> to slow, because there is the communication with the host.
>
> (What to do with the AD-conversion of 16C71, using the Soundblaster ?)
About a year ago we had similar discussions for gpsim (that is, extending
the parallel port out to real-world devices). In it's simplest form, I
think creating a gpsim module that interfaces between the simulator and
the parallel port would be a wonderful idea and not too hard to implement.
gpsim has all of the infrastructure in place to support stimuli (though as
some of you know, it's really rough around the edges). The 'module'
approach discussed a few weeks back would provide a convenient way to tap
into this infrastructure. gpsim has now become mature enough to begin
tackling these ambitious goals.
Axel's allusion to the Soundblaster interface is not too far fetched. Any
device that's available to your PC could be mapped to a gpsim module.
Keyboard LED's could serve as indicators or the serial port could be
mapped to a PIC uart.
The hard part will becoming up with a design that's fast, flexible. At
first, I had wanted to use the LCD display as a template for designing the
modular interface. However, emulating an LCD display requires a
significant amount of coding. So I'm backing off of that. I think a more
reasonable approach would be to implement an LED and a switch - these are
binary devices that are very simple to emulate, but would require the full
modular interface to abstractly connect to gpsim.
Nothing's cast in concrete right now. So I'm definitely open to ideas and
suggestions.
Where things stand:
------------------
The things that I'm planning for gpsim right now are completion of the
16f87x devices. Version 0.18.2 (in cvs) supports program memory and data
memory flash reads and writes. I'm now working on the A/D converter and
after that I was planning on porting the 18cxxx's USART to the 14bit
family. Version 0.19.0 will be released after these are done, but I'll
make minor releases along the way for those interested in experimenting
with 16f877.
The module interface development can begin now and co-developed along with
the 16f877. I'll certainly apply patches and provide any support. (But
I'll stay focused on the 'f877 until it's done).
Scott
