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Old 10-18-2013, 12:18 AM   #32
stugray
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Join Date: Sep 2013
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Quote:
Originally Posted by arghx7 View Post
With an Accessport (and a few other tools out there for various applications), Cobb has cleverly managed to use built-in RAM on the stock ECU so that some realtime changes are possible. So when you tune a WRX with AccessTuner, you get a small list of "realtime maps" which include primary fuel and spark, boost control, rev limiter, etc. This is a tiny portion of all the normal ROM values, but it's all you need for most tuning activities.
Thanks for the detailed response.
The systems I work on give direct access to the running SW via a JTAG or serial "terminal" access.
Either of those give access to the RAM and you can manipulate memory or registers directly. However there is an OS that gives terminal access. JTAG is in hardware so it works even without code support running on the ECU

So I looked at the SH7058 manual and there IS a AUD (Advanced User Debug) port that allows direct read/write access to the system RAM while the code is running.

I thought that might be how Accessport was manipulating system parameters while in operation. You just need the correct header file for the ROM and you would have access directly to MAP data, assuming any MAP data is stored in RAM during operation.

Do the stock ROMs store any MAP data in RAM?
If so the AUD port could be used to manipulate it (Assuming it is brought out to a header or test points)

Last edited by stugray; 01-11-2014 at 02:50 PM.
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