Problems with erasing eeprom in PIC 16F877

[sandy wilson]

Has anybody run into a problem where the EEPROM memory in a PIC16F877 is erased spontaneously.The rest of the code seems to be ok it just looses what's stored in the eeprom. We've had two pics do this and we can't find any reason why.

If anybody has seen this do they have a solution.

Thanks for any help

Sandy

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This message was ported from CCS's old forum
Original Post ID: 144515112

[PCM programmer]

:=Has anybody run into a problem where the EEPROM memory in a PIC16F877 is erased spontaneously. The rest of the code seems to be ok it just loses what's stored in the eeprom. We've had two pics do this and we can't find any reason why.
:=
:=If anybody has seen this do they have a solution.
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I only found one comment on this in the Piclist archives.
See the link below.

A few questions:

1. What version of the compiler are you using ?

2. Are you writing to the EEPROM at the same instant when
power is shut off to the PIC ?

3. What voltage are you running the PIC at ?

4. What crystal frequency are you using ?
Is the PIC rated to run at that crystal frequency ?

5. Are the PIC's power supply, MCLR, and oscillator circuits
designed properly ?

I don't have any experience with EEPROM losing its contents.
The only time I've ever seen chips get erased was with Lattice
GALs. For example, if I had a 16V8 on a board, and the +5v
bus got accidently shorted to Ground, it could erase the GAL.
(This may not be particular to Lattice -- those were just the
GALs that I was using).
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515120