I have a small circuit using the 9536XL CPLD. The complete machine uses
64 of such circuits. I have tested it on the lab and everything works just fine.The problem is the other day, while at the client premises, I saw something wrong with one of the boards. The CPLD stopped responding to the commands sent by the computer. As I had no test equipment available, I just tried to send some reset commands to the board and get no response. I turned power off to change the board, but just before replacing it I gave it another try. To my surprise, everything worked fine this time. I did some intensive testing to the board, and again everything went OK.
To me, it looks like the CPLD lost its configuration. Is this at all possible ? If so, what can I do to prevent this from happening ? Anybody seen something like this before ?
NB - it is a 2 layer board (no GND plane) about 3 sq inches.
Thank you for your time.
Josep Duran