A standard defition format for ECMs

[Paul Blackmore]

Dave,

Very impressive. I believe that XML has a big role to play in ECM
definitions. Kudos for actually doing something about it and implementing
your ideas. I for one will support it in any future software development
that requires ECM definitions.

The latest version of EFIlive V4 uses XML to store vehicle data stream
definitions. It was the obvious choice for such definitions.

A few issues that I have encountered when defining ALDL data stream
definitions that may also be relevent to defining the same data in the
ECM.....

As well as Scale and Offset for converting 8 bit values into their
real-world units, I have also found it necessary to include: Invert and
Reverse boolean flags. Invert first inverts the rax byte value (i.e.
1/(rawbyte+1)) and reverse first subtracts the raw byte value from its
theoretical maximum (2^bits)-1. Each of these operations is carried out
prior to multiplying the scale or adding the offset.
Although it has been pointed out that the Reverse flag is not strictly
necessary.

Secondly, I didn't see it but it may be in there - some raw byte values
require a lookup table as they are not linear scales.

Good work

Paul Blackmore

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Dave Plummer wrote

Date: Thu, 15 Feb 2001 14:47:51 -0800
From: Dave Plummer <davepl at MICROSOFT.com>
Subject: A standard defition format for ECMs, with LT1 as an example

I got bored a while back and decided it would be a good thing if there were
some standard way of defining what does what in any particular automotive
ECM.   So, as my contribution to the hobby, I have created an XML Schema for
describing automotive PCMs and a sample XML definition of the LT1 flash ROM.

You can find out more and download the schema and LT1 example here:

http://www.daveandnikki.com/ecmdefinitions.htm



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