repair an 8051 PCM

[NomakeWan]

You can't put power on the flash chip to program it without that power also powering the rest of the circuit assuming it all shares a common power supply.

Except that this isn't necessarily the case. For example, I have an ICP header on one of my prototype boards that goes to the pins on my microcontroller required to program it were it to go faulty. Those pins are also used to talk over I2C to a DAC, and for other things. But if I'm not powering the board from the input rail and am instead connecting to the ICP header, then the rest of the circuit is unaffected as it's not powered up. Sure the signals I'm sending to the microcontroller are going to also hit the DAC, but the DAC isn't receiving any power so it won't matter.

Similarly, if GM designed a header to allow in-circuit programming, why would you assume that programming the flash chip via this header would somehow power up the whole PCM? Similarly, if one were to make a jumper connector to flash the chip directly, why would the rest of what the chip's connected to matter since there's no power to the PCM?

[steveo]

my first dumbass thought was nipping the processor vss and reattaching it after. but im an ameture with this stuff and the chances of it catching fire are greater than zero.

[space387]

So this bytes. Got my parts in but found the Ebay programmer I bought requires a parallel port and the program for it wont accept a serial port. Working with Win 7 on that computer if it helps.

I looked back and the only difference I can find from the 28F512 in the 8051 ecm vs the 27SF512 used in my Corvette is pin 2. the 28F leaves it blank where the 27SF list it as A16. I am really out of my league reading these data sheets but one would think you could use the Burn 2 with an atapter and a little adjusting of some settings.

27SF512 Data sheet
28F512 data sheet

For the most part it seems like all should carry over but I'm not sure about the unused pin and how that would play into the programming.

Side note I have the sockets in and set already, that went a lot easier than I expected

[kur4o]

Don`t bother with burn2. They noted that other chips are not supported. It could be a software thing or a lack of 12v source needed for erasing and writing.

Get an old PC with parallel port and xp and use the programmer you have. There are no requirements other than parallel port, so look for the cheapest one.

[NomakeWan]

Space, when you look at the datasheets the only thing that matters is the programming/flashing section. This section explains which pins are used for this and how. I guarantee you that A16 won’t matter for programming purposes, so if the rest of the pins are the same, the reset vector is the same, and programming voltage is the same, you should be fine.

[space387]

Don`t bother with burn2. They noted that other chips are not supported. It could be a software thing or a lack of 12v source needed for erasing and writing.

Get an old PC with parallel port and xp and use the programmer you have. There are no requirements other than parallel port, so look for the cheapest one.

the 27SF512 sent by Moates denotes an 11.4-12v VppH for writing/ erasing the chip. not sure how the Burn 2 gets it. I had an older computer that I have not used in a few years but on trying to start it up for this it wont even post.

[kur4o]

They are different type of chips. The 27sf512 is eprom erasable type and the n28f512 is flash type. It is likely to use different commands set for the flashing process. So it must be a software limitation.

You can try contacting Moates with the issue. They should be able to tell if it is possible.

[space387]

Thanks Kur40, I emailed moates for the kicks and giggles but dont expect a fix.

[steveo]

amazon will have a usb to parallel or pci to parallel solution on your doorstep overnight for like 15 bucks

there is a usb to anything adapter these days

[space387]

I finally did it. I resurected my 12 year old gaming PC with a parallel port and worked my way through the files and switched but I have successfully burnt a chip, I think. About to fill the other and try to remember which one is T and E side

[steveo]

nice! the guys that originally developed this program probably had a 486. nothing wrong with old hardware.

if it doesn't boot at first, after you ensure your socket is good, remember the height of the chip in that stupid socket is critical. since you have to snip the 'floor' out of the socket, and putting it back is a crazy glue job, you might need to shim the chip until the pins make contact.

i fought with that one for a bit my first time thinking my chips were programmed incorrectly

[steveo]

blue plug tside red plug eside by the way

[space387]

nice! the guys that originally developed this program probably had a 486. nothing wrong with old hardware.

if it doesn't boot at first, after you ensure your socket is good, remember the height of the chip in that stupid socket is critical. since you have to snip the 'floor' out of the socket, and putting it back is a crazy glue job, you might need to shim the chip until the pins make contact.

i fought with that one for a bit my first time thinking my chips were programmed incorrectly

thanks, I actually just tested it in the can and it wont communicate but its late and I have to work the next 2 days. I will absolutely try shimming before going crazy though.

[space387]

IT LIVES!!! Seems I didnt have good contact on a few pins. I also noticed the data stream is more consistent.

* it lived. After one startup it wont communicate again. maybe the chips moved,a project for another time

[space387]

So steveo I am now being met with an issue sending a tune. In EE hack I open up the program and connect just fine. I see data like Map fluctuating and TPS responds when I push the pedal. When I go to flash and hit stability test it says it can not get the access key to release( I think) and says to cycle the key but nothing changes it. Any Ideas? I am using the starter bins from your website.