Thank you, Steve.

Yes, I have this read also in the Atmel errata sheet.
But strangely enough, I can not reproduce this on my AT89S53 or AT89S8252 devices.
I programmed the following code:

org 0
mov p1, #0
jmp 0

But serial programming was working further.
Maybe, since I use my self written programming software ?

Have you any short code, which fails on your device ?


I'm happy, that you point not a reliability problem. So I can use it also in future.
I use the AT89S8252, because 2kB of data EEPROM inside.


Peter