On Sun, 10 Aug 2014 17:12:32 -0400 Neil wrote: > Getting back into PIC dev recently, and I've run into a=20 > somewhat-familiar EEPROM issue. I'm preloading a PIC18F46K22 with 400+=20 > bytes of data and it works fine initially, but after some time (with no=20 > EEPROM writes from the code) the data is getting corrupted. Swapped the= =20 > chip and same issue. Without any writes, it seems it's not the old=20 > wear-leveling issue with writing to some cells possibly degrading or=20 > corrupting other cells. The only thing that happened from working to=20 > non-working is that power was cycled several times. I wonder if you have any bootloader code present in your PIC. I had many problems with the bootloader code modifying the EEPROM code through reset problems. So, even if the program itself didn't do any writing, the modification code was present, and it did get=20 executed in some cases (maybe 1 in 50 or so). The only solution was to remove the bootloader code and program the entire processor. Note: it wasn't exactly that PIC model, but another from the same family. John --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .