Mark Butcher

Killing chips

Discussion created by Mark Butcher on Feb 7, 2006
Latest reply on Feb 7, 2006 by Mark Butcher
Hi All
Just wondering whether any one knows whether it is possible to destroy HCS devices by incorrectly deleting Flash?
I have just built a board with the NE64 and I connected it to the debugger. I wanted to download a boot program but wasn't concentrating much - I had seen that the FLASH was not completely blank (I assume it can have a bit of garbage in it when a chip is fresh from the bag). As I said, without thinking I sent a couple of commands to delete the FLASH.
To be exact:
- a write to a FLASH location (any location to prime delete)
- CMD_FLASH_ERASE to FCMD     (prepare erase command)
- CBEIF to FSTAT              (start erase command)
I forgot to set up the Flash clock divide to produce a clock of between 150k and 200k...
Afterwards nothing worked and the board, which was originally consuming a few milli-amperes was taking about 400mA and the NE64 was getting rather hot.
Not concentrating entirely, I don't know exactly whether it all happened when I sent the above command sequence or not but it seems quite likely.
Anyone also managed to produce such destruction? In any case it looks as though I'll have to solder a new one in tomorrow but I don't want to see whether I can repeat what happend.
So any one with similar experience?
Mark Butcher