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Write/Verify a Flash ROM

Posted: Fri Nov 26, 2004 11:57 am
by ruelnov
Hi,

I've encountered several bios chips which could be flashed successfully with Uniflash and passing the Data Verification step.

But these chips seems very unreliable in actual use, and I need to reflash time and again to enable the system to boot.

Is there a utility that could do a reliable write/verify operation on all addresses of a Flash ROM?

The objective here is to be able to pre-qualify a Flash ROM through a write/verify test before flashing.

Any leads?

Can this be implemented in Uniflash?

Posted: Mon Dec 06, 2004 11:41 am
by ruelnov
No one is ever interested in this?

Posted: Mon Dec 06, 2004 2:18 pm
by ajzchips
I believe it's something quite hard to do. I've had some BIOS chips that would flash perfectly, verify perfectly, pass any test, but wouldn't retain the firmware for over an hour (or a few days).
The defect is simply that they weren't very "non-volatile", and checking this would always pass with flying colors immediately after flashing, but then fail some time later.

Posted: Wed Dec 08, 2004 6:51 am
by ruelnov
Uniflash already has this write/verify feature. I wonder if it's possible to add a separate write/verify module that allows for 1-10 passes of write/verify test for all addresses of the Flash ROM. I believe that increasing the number of passes would expose the unreliable addresses, much like how deep RAM diagnostic programs do it.

Posted: Sun Dec 26, 2004 5:00 pm
by ruelnov
Can I hear what Rainbow has to say on this?

Posted: Mon Dec 27, 2004 10:26 pm
by Rainbow
You can use "uniflash -save" to read data from the chip to say 10 files and then do "fc /b" compare on the files. This can be put in a batch file.

Posted: Tue Dec 28, 2004 6:04 pm
by ruelnov
If I understood you right, you mean extract the BIOS image 10 times with different filenames for each instance then do a binary file compare, correct?

Is this "fc /b" available in Uniflash?

Posted: Wed Dec 29, 2004 3:25 pm
by Rainbow
Yes, flash it, then save e.g. 10 times and compare. fc.exe is standard DOS program. You can also use some external program to wait some time between the saves if the chips lose the data after some time.