Hi Bob, thanks for your hint.
The production serial consists of the wafer number, y and x coordinates and is far to long for my purpose. I'd like to fit the serial into a 16bit ModBus register which currently works pretty well with my two usersig-bytes. > Note this comment from the above URL: > > (void) SP_ReadCalibrationByte( offsetof( NVM_PROD_SIGNATURES_t, > LOTNUM0 ) ); /* First read after reset or possibly Power Up returns > zero, so read then toss this value */ > > I reported that issue to Atmel when the parts first came out. They > said they could not reproduce it. > A few others have seen the same thing over the years. Thanks, I already use the code from Atmels app-note and as far as I can remember I'm also skipping the first read. > So try reading your USER_SIG value twice, see if you get what you > expect on the second try. > All reads after the very first one, after a reset, work just fine. Good point. Guess I'll give it another try. Anyway, I read that there also is an erase command for the usersig and avrdude does not implement any option for it. I'll try the current AVR Studio and will see if I can somehow change my usersig in there. I'll send my findings tomorrow. Regards, Alex _______________________________________________ AVR-chat mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/avr-chat
