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Discussion Groups | 68HC12 | Re: EEPROM erase on power down?
Join our technical discussions about Freescale Microcontrollers: M68HC12. (Freescale Semiconductor is a Subsidiary of Motorola).
Re: EEPROM erase on power down? - eric_cina - Mar 30 10:07:19 2008
Thx, I'll look into the stability of the our oscillator. Right now
I'm reaching for anything because I can't seem to reproduce the
problem.
We have a few EEPROM routines that are very careful to keep EEPROM
protection enabled and to keep a bulk erase from occurring so I
think that these are unlikely to cause a problem. The bulk erase
command is only called from 1 place when a certain back door command
is given by the user.
If the EEPROM was wearing out, that would not cause the entire
EEPROM to get wiped out, would it?
--- In 6...@yahoogroups.com, "Edward Karpicz" wrote:
>
> Eric wrote:
>
> > We have a legacy product MCthat is using the 68HC812A4 micro. We
> > recently have several units where the on board EEPROM appears to
have
> > been wiped out. This problem is very hard to reproduce and I
don't
> > have very many clues as to why this is happening.
> >
> > Should I be concerned with power up, power down, and/or resets
somehow
> > causing the EEPROM to be wiped out? We are using a DS1233 reset
chip
> > with our micro.
>
> I would start from checking oscilator robustness. D60A's with
their slow
> Colpitts startup could get selferased if /RESET is released while
oscilator
> was not stable. Don't know how that could apply to 812A4.
> Do you have any bootloader? Is there some command that could cause
erase of
> whole EEPROM array? If yes then what if noise is recognized as
such command?
> Buffer overrun?
>
> Edward
>
> >
> > Thanks in advance,
> > Eric
>
------------------------------------
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I'm reaching for anything because I can't seem to reproduce the
problem.
We have a few EEPROM routines that are very careful to keep EEPROM
protection enabled and to keep a bulk erase from occurring so I
think that these are unlikely to cause a problem. The bulk erase
command is only called from 1 place when a certain back door command
is given by the user.
If the EEPROM was wearing out, that would not cause the entire
EEPROM to get wiped out, would it?
--- In 6...@yahoogroups.com, "Edward Karpicz"
>
> Eric wrote:
>
> > We have a legacy product MCthat is using the 68HC812A4 micro. We
> > recently have several units where the on board EEPROM appears to
have
> > been wiped out. This problem is very hard to reproduce and I
don't
> > have very many clues as to why this is happening.
> >
> > Should I be concerned with power up, power down, and/or resets
somehow
> > causing the EEPROM to be wiped out? We are using a DS1233 reset
chip
> > with our micro.
>
> I would start from checking oscilator robustness. D60A's with
their slow
> Colpitts startup could get selferased if /RESET is released while
oscilator
> was not stable. Don't know how that could apply to 812A4.
> Do you have any bootloader? Is there some command that could cause
erase of
> whole EEPROM array? If yes then what if noise is recognized as
such command?
> Buffer overrun?
>
> Edward
>
> >
> > Thanks in advance,
> > Eric
>
------------------------------------
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