OT Corrupted internal flash on AT89C51ED2

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...
OT Corrupted internal flash on AT89C51ED2

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...
AT89C51ED2: Selecting external vs internal flash

I would like to set a (fuse?) bit to select the external Flash/PEROM as program memory instead of default Flash internal to the AT89C51. Is the BLJB bit the one I want to set? How do I set it?
AT89C51ED2: Selecting external vs internal flash

I would like to set a (fuse?) bit to select the external Flash/PEROM as program memory instead of default Flash internal to the AT89C51. Is the BLJB bit the one I want to set? How do I set it?
Atmel AT89C51ED2 & user boot loader

Hi, You do not know anybody, how configure processor, to start user's boot loader in At89C51ED2? On what address begins room for boot loader ? Documentation show in F800 and FC00.