topic Re: Lost Program in 8-bit Microcontrollers

Lost Program - AP64

Scott134 — Wed, 23 Jul 2008 02:59:18 GMT

I am using the ap64 chip. Every once in a while, a unit returns without the program loaded or a part of the program missing. Units are shipped all over the world. I can re-load the program and unit seems OK. Anybody have any ideas?

Thanks

Added p/n to subject.

Message Edited by NLFSJ on 2008-07-23 12:31 PM

Re: Lost Program

peg — Wed, 23 Jul 2008 05:29:14 GMT

Hello and welcome to the fora, Scott.

Does your code write to flash for EEPROM like storage?
Does it use a serial bootloader?
What did you use to programme it in the first place?
Is the device totally erased or just damaged so it won't run? (partially erased, reset vector only will disable it)

Re: Lost Program

peg — Wed, 23 Jul 2008 06:14:31 GMT

Hi again,

Add:
Do you have the LVI setup correctly to handle out odf spec power supply on power up/down etc?

Re: Lost Program

Scott134 — Wed, 23 Jul 2008 18:36:30 GMT

Hi Peg,

I am using a serial bootloader. The bootloader is still there. Code is not writing to eeprom. Bootloader is loaded by one of our vendors. Program loaded by us through serial port. The best I can tell is that it happens after product is shipped.

Thanks,

Re: Lost Program

Scott134 — Wed, 23 Jul 2008 18:37:33 GMT

The LVI is disabled.

Re: Lost Program

peg — Wed, 23 Jul 2008 18:56:45 GMT

Hi Scott,

Presumably the bootloader can erase all of the programme area?
Why do you not utilise the LVI?
Without some form of low voltage protection all bets are off. On power up/down as the rail passes through the region of below spec but above the point where it still tries to run anything can happen wrongly. This is made worse by the fact that there is some extant code that can erase the programme.
If you don't have a valid reason not to, setup that LVI module.

Message Edited by peg on 2008-07-23 10:03 PM

Re: Lost Program

Scott134 — Wed, 23 Jul 2008 19:34:25 GMT

Hi Peg,

Thanks for the idea. I will give it a try. I may not know if it works or not for several weeks or months. Either way, I will let you know.

Thanks,

Scott

Re: Lost Program

Scott134 — Tue, 28 Apr 2009 02:49:20 GMT

Just an update for all who helped. I enabled the lvi but still had a few problems. It appears we had some keypads that would intermittently short. They were used in entering a "program mode"