How to program\flash old NXP (Philips) XA-G37 (80C51) uC OTP chips? - Page 1
Forum section: electronics / general

author: lukes
author_rank: Newbie
timestamp: May 01, 2021, 05:52:28 pm
content: I was wondering if anyone knew how to program\flash a program file onto an old NXPXA-G37microcontrollers which use extended 80C51 architecture? I have some old industrial equipment that uses these chips for firmware and the manufacture wants $1500 per chip to send the latest firmware. I am willing to buy one chip with the latest firmware and copy the program (if the security bits are not set) and program it to old surplus of other chips but I not willing to buy a bunch at that price.I am somewhat familiar with programming newer microcontrollers that support JTAG or ISP but it appears these chips don't support that. Page 33 of thedatasheetsaysQuoteThis is not very helpful as that URL is gone to history. I could experiment with making my own programmer with an arduino but since these are one time program I feel like it will be wasting more chips learning how to do it then I am willing to do. Ifound this document(page 33) which shows the waveform to program older 80C51 chips but is there something off the shelf or already figured out I can buy to do this?

author: mindcrime
author_rank: Unknown
timestamp: May 01, 2021, 07:46:28 pm
content: Does the Internet Archive capture of that page have anything useful?https://web.archive.org/web/19970416020800/http://www.philipsmcu.com/ftp.html

author: lukes
author_rank: Newbie
timestamp: May 01, 2021, 10:54:45 pm
content: Mindcrime, I looked at this but I didn't find much on programming and seems to old for the XA chips. The XA would probably be in the 1998 and later stuff which all is not archived unfortunately.

author: amyk
author_rank: Super Contributor
timestamp: May 01, 2021, 11:57:16 pm
content: What are the chances they won't set the security bits, if they're charging $1500 for it...?There are services that can break the protection (and for such an old family is probably easy), but they are not cheap (I guess 1-2k$)There are programmers available. They aren't cheap either.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 02, 2021, 01:09:37 am
content: Quote from: lukes on May 01, 2021, 05:52:28 pmOf course, the security bits will be set, so a simple copy will not work.How many is 'a bunch' ? - you may be better to negotiate with the supplier for a quantity price ?

author: nctnico
author_rank: Super Contributor
timestamp: May 03, 2021, 05:00:20 pm
content: Quote from: lukes on May 01, 2021, 05:52:28 pmThis sounds a bit shady; you basically want us to help circumvent / violate the manufacturer's copyright.As other said it is likely that the security bits are set so reading the chip is likely a futile attempt (if you are even able to source blank chips; you can only write these chips once so the existing chips are no use). IMHO you need to do a cost versus benefit analysis: how much do you gain from running the latest firmware version. If your gain is less than the price of the chips you can contact the manufacturer and simple state: at this price it makes sense for me to upgrade. Can we make a deal or not? If they don't budge and you need 10 or more of these chips then rewriting the firmware and replacing the entire processor with a more modern microcontroller is not outside the realm of possibilities (=it could be financially viable). The chip you linked to is not particulary big/complex so likely the functionality isn't that complicated. The advantage of rewriting the firmware is that you can add your own features and maybe team up with other users of this equipment to share the costs.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 04, 2021, 04:42:18 am
content: Quote from: nctnico on May 03, 2021, 05:00:20 pmThis was "some old industrial equipment" so the part needs to be a drop-in replacement.An exact pin-match for the XA in PLCC44 is going to be a challenge.There are modern 8 bit MCUs similar-or-better to XA resource, but the PLCC44 in a very old package and no new MCUs are made in that.

author: technix
author_rank: Super Contributor
timestamp: May 04, 2021, 05:58:26 am
content: IIRC there are board-to-board connectors intended to mate with a PLCC44 socket. If you can track those down maybe you can just spin a replacement PCB with a modern MCU plus all the modern amenities (USB interface, W5500 based Ethernet, ESP8266-based Wi-Fi, etc) while still being compatible with the old rig.

author: nctnico
author_rank: Super Contributor
timestamp: May 04, 2021, 08:20:35 am
content: Quote from: PCB.Wiz on May 04, 2021, 04:42:18 amIf the original microcontroller can be replaced then it is in a socket (which probably is the case because it is a one-time-programmable microcontroller). Remove the socket and solder in a header connector. Likely this is a two layer, through hole board so easy to rework. From there you can use any modern ARM microcontroller.

author: technix
author_rank: Super Contributor
timestamp: May 04, 2021, 08:42:11 am
content: Quote from: nctnico on May 04, 2021, 08:20:35 amActually I'd suggest solder in round-pin PGA socket, which can accept either an extension PCB or a PLCC44 socket, so you can go a lot of different ways. Those are also a lot easier to find than the PLCC44 mating connector I mentioned above.