Debugger board for P4 ECMs

[Ludis Langens]

Swayze wrote:
> 
> would it be possible to use this as an 'emulator' to setup and 'tune' the
> .bin  on the fly? If so I'm in.

Walter Sherwin wrote:
> 
> What steps, in general overview type terms,  would a person have to go
> through in order to adapt this board as a plug-in style emulator within an
> ECM/PCM controlling a running engine?

It isn't an emulator.  The board is most useful to anyone doing software
development in the ECM or figuring out how the hardware works.

It has some use for on-the-fly table changes.  The SRAM allows a few
tables to be relocated from the EPROM into SRAM.  This requires software
support in the EPROM.  The '727, '730, and '749 ECMs could do this
without an add on board because they can already accept an extra SRAM. 
Other ECMs like the '165, '748, and '8253 would need this board because
they don't have any extra built in SRAM.



Swayze wrote:
> 
> would it be possible to
> -configure it with a cabled edgecard connector

Um, yes.  A PCB could be made to accept either an edge card connector
(0.2" spacing) or a header (0.1") for a ribbon cable.



steve ravet wrote:
> 
> Could the software for it be put
> into a flash or EPROM and mapped into unused ECM address space?

Q: If it is in unused address space, how does it get executed?

A: The normal EPROM is programmed to JSR to the extra EPROM.

Q: If it needs to be changed anyway, then why not leave everything in
the normal EPROM?



An idea: Extend the PCB to include a socket for a 27C256 and 32Kbyte
SRAM, either of which could override the EPROM in the MEMCAL.  The PCB
could be designed such that the extension can be cut off when using it
in confined spaces.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/

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