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I need some help positively identifying this CPU. See pic. Thank you in advance.

if its a gm part it'll be custom silicon based 99% on a production part where the numbers on the package dont relate to what the chip is. that is to say gm numbers on the chip that are not publically known. you'll need to compare what age, family the hardware is, what is known about other devices in the family, if you can get a bin somehow/somewhere, look at the data to try and see what looks by eye like different mainstream instruction sets, try different cpus in disassemblers etc.

antus wrote:if its a gm part it'll be custom silicon based 99% on a production part where the numbers on the package dont relate to what the chip is. that is to say gm numbers on the chip that are not publically known. you'll need to compare what age, family the hardware is, what is known about other devices in the family, if you can get a bin somehow/somewhere, look at the data to try and see what looks by eye like different mainstream instruction sets, try different cpus in disassemblers etc.

It is a P04 PCM. I am trying to JTAG it but need to know which it is to get pins.

have you tried tracing p01 bdm pins back to the cpu then trace the same pins on p04 to find usable board locations? if the ones on the standard edge connector line up at the cpu you'll probably find its the same cpu. but you'll need to update the registers in the instructions in the hex of the usb-bdm-nt setup to suit p04. I think theyre like poke commands to turn off watchdog. not 100% sure of that, though. the author of the app might be able to help if you get the hardware figured out and need help with the init.

antus wrote:have you tried tracing p01 bdm pins back to the cpu then trace the same pins on p04 to find usable board locations? if the ones on the standard edge connector line up at the cpu you'll probably find its the same cpu. but you'll need to update the registers in the instructions in the hex of the usb-bdm-nt setup to suit p04. I think theyre like poke commands to turn off watchdog. not 100% sure of that, though. the author of the app might be able to help if you get the hardware figured out and need help with the init.

Actually I did JTAG to the P01 a couple of days ago since I knew it was one that has been widely done before. Problem is that unlike the P01 and P59, there is no edge connector on the P04. The board is completely different. Also the markings on top of the CPU are different as well. Since this is the only P04 I have, I can't afford to remove any of the resin covering to try and uncover the silicon to look in microscope. I will say this though. If you look on the P04 where the connector pins are soldiered in, pay close attention to the circles where the soldier goes. Some of them have some kind of markings, almost like telling that certain pins are special and have a different purpose. If only we knew what they meant. You can see them on the attached pic.

Maybe something here that'll help ... USB BDM NT

It's my understanding that the USB BDM NT & Software should work on all M683K based chips, however if a Flash Chip is not described in it's db it'll need to be, and that can be confusing unless they finished cleaning it up in the newer versions of software.

-Enjoy

darkman5001 wrote:If you look on the P04 where the connector pins are soldiered in, pay close attention to the circles where the soldier goes. Some of them have some kind of markings, almost like telling that certain pins are special and have a different purpose.

It's not clear what "markings" you are referring to. Could you point one out?

Joe.