12F629 won't erase and bandgap save?

[Keith55555]

Hi all,I tried programming a 12F629 a second time after thinking I may have configured things wrong.EPIC says I have successfully accomplished an erase but if I look at the first place in memory,it's not erased(everything else is) and of course when I hit run . EPIC then gives me an error that it indeed isn't erased and won't complete downloading the program into it.Is this chip destined for the ol' solder braid?I program a 675 right after the attempt on the 629 and it erases properly.Same power supply etc.
Also,I know that EPIC does a saving of the calibration of the internal osc(it won't let me even try programming without it on this chip)but does it save the band gap settings as well?Can't seem to find the band gap reference register in the data sheet.I'm new to these two and I know a lot has been written about them up here,so forgive any redundancy. -Keith

[Melanie]

Can't comment on EPIC matters as I don't use one, however the Bandgap is not too significant as it just trims the internal voltage references for POR and BOR to meet the published specifications.

However, if a byte/or bit in Flash won't Program or Erase then the device is usually only suitable for land-fill. Return it to your Point of Purchase under warranty if it applies.

Melanie

[Keith55555]

Thought so.Wish that could be avoided because I do think I programmed it in an illegal manner that I wish the programmer would have caught.Wouldn't bother returning it.My cost is unsoldering it and I only use surface mount stuff,so that's a big enough investment.Onwards and Upwards.
Even though I understand the little significance of the relationship to POR and BOD for the band gaps ,I would like to know how to do this.I know you've addressed this so don't bother ,I'll look it up here but maybe I missed it but could not find a reference in the 129 pages of the data sheet.Thanks for your comment.

[Melanie]

I know I've discussed this on the email forum as well, but this thread might be what you're after...

http://www.picbasic.co.uk/forum/showthread.php?s=&threadid=100&highlight=thread

Oh, it's not in the Datasheet as it's not one of those things Microchip expected you to play with as it's a factory manufacturing setting.

Melanie

[Keith55555]

Hmmm,that's interesting since if erasing a part can accomplish the band gap erase...and...and...and!Anyway thanks.I'll study that and see it's usefulness to me.
Anyway and also,I soldered in a new 629...it's my programmer.Replaced all the relevant parts relating to the programming voltage(wasn't getting the 13 volts).Now able to erase with ease,nice and erased and can see that to be true...BUT! once I run it to program I get an error at 0000;without exception.Oy vey!I think it's time to start researching programmers.This is the third time I've replaced parts on the EPIC.I know that's not your programmer of choice but ...it used to work,so...Sometimes I recall fondly the days I toggled in ASM with 8 switches on a 6502...Nah!