27c322 bug ?

Rom1

Hi,
I have a T56 and some 27c322 are not programming correctly.

- The chips are fully erased, blank checked OK.
- Programming step goes well.
- Verify check tells me there is differences with binary image.

The same chip program OK on a Wellon VP280.
I also cross checked: programmed by VP280 are verified OK by T56; and programmed by T56 are both verified as ERROR on T56 and VP280.

I have another batch of 27c322 that is ok and program well on both.
Maybe a problem in settings or algorithm ?

Regards

Rom1

Thanks for your help.

I'll already tried changing pulse to 100us with no success.
Yesterday I pushed VDD write to 6.5v and every chip is programming right with only this change.


I'll give a try to both 200us and VDD 5.5v and keep you informed.

Rom1

Changing pulse time didn't work.
Reducing VDD was a success. How can you explain that both reducing and increasing VDD helps ?

Thanks a lot !