Hallo for everyone i am repairing ECU with a MC68376 CPU . I need ask if is possible read this CPU for replace with new for example with BDM .

thanks everyone

I'm not sure if this forum is the correct place to talk about reverse engineering, but I like this topic so let's see if I can help.

My understanding is that the presence of a BDM connector will be highly dependent on the ECU manufacturer. I have no experience operating a BDM interface, either, but I do believe that this is the appropriate interface for the MC68376. If you're lucky the pins will already be on the PCB. Be careful; I've heard that in some cases the pin labels are inverted compared to a standard BDM interface (if such a thing exists).

More pertinent is the possible identification of the flash memory chip that could be on the ECU circuit board. Have you opened up the ECU to look at all of the components?

What is your motivation and your end goal?

Thanks Obeisance.
Sorry for post in this Forum . I don't know where i can post my question .
Yes in board pcb there is BDM output , i must see if there are pin inverted i see normal motorola BDM output 5+ 5 pin .
In board there are 1 flash eprom 29f040b and one 128Kx8 SRAM and one 93c86
You ask why i need read this CPU?
I repair ECU for engine and sametime problem are in the driver and sametime problem are in a MC68376 are not good not working or became hot with with excessive power consumption. So i need change it with new , problem are because no more new ECU are avaiable because the ECU factory was closed so i ask if i can read working CPU and change Cpu in a not working ECU.


thanks

I'm not entirely sure I understand what your electrical problem is, but if you believe that replacing the MC68376 microcontroller will sufficiently fix your problems then I expect that you don't need to read the ROM from the 29f040b chip via BDM. I mean, if the microcontroller is broken but the flash memory on the EEPROM is okay, then I expect that the microcontroller can be switched without conflict- all of the ECU code will remain on the EEPROM chip.

However, I expect that hot components indicate a short circuit on the PCB (or in the car's wiring harness)- if this is the case then replacing microchips will probably not rectify the problem.

Do you plan to simply reflash the ECU code onto a replacement ECU, or are you planning on de-soldering and replacing microchips to repair the broken ECU?

May I ask which vehicle the ECU is for?

i was try fix problem in pcb or same problem but nothing .. that was not the problem ..so i desoldered microcontroller from pcb and i found low resistence in a VDD pin to VSS pin in microcontroller without pcb, so i deduced that the problem is in microprocessor.
now i can change it with new but i dont need program it ?

I desoldered Flash too and read too .
you think that if i replace microcontroller with new every thing will be good ?but BDM interface is used only for flash external eprom ?


this ECU are used in a agricultural machine.

thanks

That is correct: my expectation is that the microcontroller program resides entirely on the flash memory chip (except maybe for the code for integrated microcontroller functions such as the time processor unit (TPU)- if you're lucky then the controller that you use as a replacement will have the same TPU mask set installed).

This means that the use of BDM would be to send commands to the microcontroller such that it interfaces with the flash memory (assuming that it was wired such that it could be re-programmable). If the flash memory is not damaged, then I expect that no programming steps will need to be taken.

thanks .

in any case can i read TPU Memory in a good microcontroller and reprogram in new ? if new microcontroller are different set ?

sametime i need change program in flash (so i need desoldering Flash) for example when one ecu break down so i can buy used ecu and i flash memory in used and all is good !! but sametime for different Engine power are same microcontroller and pcb but if i change only flash memory ECU aren't good . So i think that not change only flash memory program.
BDM can be good for me for program flash memory because ECU is immersed in the resin. Are only BDM pin out .

I have no experience with changing the TPU programming - I only know it can be done because of the reference information for the MC68376:

https://www.nxp.com/products/no-longer- ... tation_Tab

In my project with this microcontroller, there was an alternate mechanism to read the flash memory (CAN bus). Once I had access to the flash memory data, I disassembled the binary and have since then read how to reprogram the flash memory without a BDM interface (over an OBD port K-line). My project was somehow more straightforward than yours.

It sounds like you have a difficult task at hand. Good luck.

Are there different versions of MC68376? I acquired about 20 MC68376BACFT20 many years ago and I plan to design an evaluation board, just one of the many projects in the back burners. Now I'm curious to know whether a design based on MC68376BACF20 can serve as a simulator for the ECU.

thanks i need try , i see in the BDM programmer can read internal flash memory .
Now i need buy microcontroller and first i try with out program it and second program it with BDM.
thanks everyone .
now i wait microcontroller.

I'm not too familiar with the different variants of this chip- I've read in some places that there are even versions which were even rated up to something like 25 MHz or so (rather than the usual ~20 MHz) even though there was no datasheet indicating so.

According to the datasheets (apbmech.pdf), the parts that you ordered have TPU mask set A (MC68376B A CFT20), blank mask ROM, are temperature rated from -40 to 85 C, can be ordered in a package quantity of (multiples of?) 24, and have a frequency of 20.97 MHz.

It looks like the biggest difference among variants is the temperature rating and the TPU mask set. If you had the other TPU mask set then the 'A' character would be a 'G'. I guess that none of this precludes custom TPU programming, though.

thanks .
Are arrive to me new microcontroller.
I have try change in pcb with new .
The first thing the power consumption became good like good board .
I see with oscilloscope that read memory from flash but pin out of can bus no signal so i think i need program TPU with BDM

I dont expect that the CAN functionality is tied to the TPU mask set (unless some TPU function triggers a CAN message interrupt).

The fact that you see data being read from the flash memory chip is a good sign- but maybe there is some bootloader or early runtime function in the ROM that the code is getting hung up on before it reaches the point where CAN data should be sent.

In order to troubleshoot, it would be nice to see the ROM (but this is a long and arduous path).

i have rom memory but i dont know how i can decompile it.
Do you know how decompiler are good for this ? what i can tell that there are 2 type od ECU with different power of engine and same board same hardware , but if i invert memory ECU dont start canbus , so i think that samething in MC68 are programmed I was try with BDM read internal memory but i think are code protect so i dont read nothing .


thanks