Data EEPROM gets clobbered during programming

[BrianT]

Hi Skimask,
The loop structure is fine. It shows me the full 1024 bytes of the EEPROM.

Program 2 clobbers the EEPROM. I think Jerson is thinking in the right direction that it is a programmer setup issue. The USB serial programmr I have uses different terminology to his post but I think I know what he means. The trouble I now have is that the '4620 will not program unless it is erased first. That erasure takes the EEPROM contents with it and empties the memory.

Cheers
BrianT

[BrianT]

I had faulty thinking about what the CONFIGURATION setup screen in the Melabs Serial USB programmer does. It appears to show the configuration that will be in force AFTER the programming step. Setting Data EEPROM to 'protected' does not protect it during the programming but it seems it will be protected when the program runs.

What I found solves the problem is to dig deep in the options\more options\ erase and options\more options\blank check to get the programmer to accept the fact that the chip was not blank and to program anyway and to not touch the data EEPROM during programming.

Pretty obvious after the event. Thanks to Jerson for pointing me in the right direction.

Thanks
BrianT

[skimask]

Hi Skimask,
The loop structure is fine. It shows me the full 1024 bytes of the EEPROM.

Yep, sure is. I read it wrong....Duh....