Sorry for OT, but I in big trouble!
From time to time my devices with above mentioned processors corrupt content of internal program memory. Does anyone see this behavior od 80C51ED2?
Dozsa Gyoergy
P.S. Keil C51 user since '91
Yes, RC resets are deadly to all forms of non-volatile data. But any chip with IAP capabilities can corruct the program in case the program runs awol, and the chip doesn't have a hardware-based lock support.
Have you seen any indications of watchdog resets or other troubles that may indicate that you may get a stack overflow or stack corruption? Are you using function pointers?