Sir,

I was using P89C51RD2HBP happily with flash magic for my system development. The only problem I was facing was that my original system uses Atmel 89C52 chips (12 Cycles ) with 11.059 MHZ crystal, while this device P89C51RD2HBP is a 6 cycle one and that gave some problem with kbd scanning and such timed logics. I decided to use its recent cousin P89C51RD2BN which is 6 / 12 cycle programmable. When I first time connected with Flash Magic with this chip, it connected well and I could transfer my target Hex file to it. It worked normal also after first programming in the system. But , to my horror, when I tried to reconnect it with Falsh Magic again, it still runs the normal program ! If I use the chip HBP in the same system, I can get connected. Is it possible that the chip is damaged? Also it happened with HBP chip a couple of times that it was running the program instead of getting connected to Flash Magic. Any clue?

I doubt that while programming RD2BN first time, the chip selected in Flash Magic was HBP, though it connected well. Could this have create problem?

Regards

Mahesh Vyas.