V7/V8 JDM STI ECU - BDM pin

[ultrasmurf]

I have been trying to figure out which pin of the CPU is being used as BDM pin connection. Looking at MC68HC916 pin doesnt seem to be the right processor for this. I'm checking the VDD and VSS connection, and it doesnt seem to match ( no connection when pin marked as VDD is tested using ohm meter ).

During my search about this ECU I've come about colby mentioning BDM port is available on this ECU (16 bit ECU) but I couldn't find any diagram/picture showing this.

Anyone have any information on this ECU's CPU pin out or BDM port ?



So far the closest datasheet I can find is MC68HC916 but the pin out from the diagram doesnt correlate, when I test the VDD pin (e.g. pin 40 and pin 120) or VSS (pin 41 and pin 121) the are not shorted together.



Any help will be appreciated.

[Sasha_A80]

BDM pins are clearly marked underneath of PCB of a similar ecu.
Here they are probably marked as P8хx and should be traced to CPU pins.

[ultrasmurf]

Hi Sasha,

Thanks for the pointer. Is there any datasheet for this CPU ? I can try to trace the pad to the pin, but without knowing which pad is for which purpose I dont think I can put it in BDM mode safely.

The backside of the PCB is like this, there is clear indication of P8xx but no marking as to where is the reset pin, DSI, DSO etc.

[ultrasmurf]

Just in case anyone still looking. Found the correct chip id, it's MC68HC16Y5, and colby posted the japanese spec in this post

http://forums.openecu.org/viewtopic.php?f=19&t=326

The BDM port pin I marked in red



Number is for the standard BDM pin