'Re: 16c84 reprogram cycle life?'
| The reprogrammable lifetime is in the datasheets. It is called
"Endurance" and is specified in terms of E/W meaning erase/write
cycles. It is min 1Meg and typ 10Meg for data memory. It is min 100
and typ 1000 for program memory. Data memory uses a redundant coding
method to increase the endurance above that of the program memory.
______________________________ Reply Separator _________________________________
Subject: Re: 16c84 reprogram cycle life?
Author: David Tait <comms.ee.man.ac.uk> at Internet_Exchange david
Date: 1/28/97 5:48 PM
> Yes, it is the same technology.
Thanks for letting me know. I guess I would need to know a lot
more about the physics of the failure mechanisms and something
about statistics before I could use the test memory as a reliable
measure of EEPROM endurance. Having 8 spare locations to play
with helps I suppose. Do you think it would be possible to
predict the reprogrammable lifetime of a particular PIC with
|Brian Boles wrote:
> The reprogrammable lifetime is in the datasheets. It is called
> "Endurance" and is specified in terms of E/W meaning erase/write
> cycles. It is min 1Meg and typ 10Meg for data memory. It is min 100
> and typ 1000 for program memory.
I know that this applies *on average* but my question was can we make
a better estimate of the endurance of a *particular* PIC. For a given
chip it would be nice to know its endurance more exactly than "greater
than 100, typically 1000" E/W cycles. One PICLIST contributor said
his PIC died at 200 cycles which is clearly in spec but he might have
been able to use his PIC more productively if he knew a-priori that it
would die at that point (OK, I admit this is penny pinching).
I was proposing that the 8 (or more if you sacrifice the ID locs) test
memory words be used to estimate endurance of a particular 16C84/16F84
before it is first used. I hoped you could shed some light on whether
this idea is a non-starter. It may be that the test memory has
already been used by Microchip quality control for example. If the
idea has any merit it could be a "value-added" feature of an '84
> I was proposing that the 8 (or more if you sacrifice the ID locs) test
> memory words be used to estimate endurance of a particular 16C84/16F84
> before it is first used. I hoped you could shed some light on whether
> this idea is a non-starter. It may be that the test memory has
> already been used by Microchip quality control for example. If the
> idea has any merit it could be a "value-added" feature of an '84
Actually, an idea I'd like to incorporate into my programmer, if I can get any
"official" word that it'll work, is an automatic chip-detect, at least for the
'84 (and probably '822) parts since they require a different algorithm from
the other parts. While the '84 programming algorithm would probably work okay
on other OTP parts, it put extreme stress on the 16C622JW I (accidentally) ran
it on; after erasing that chip, the locations I had previously programmed as
zeros could not be rewritten but would permanently read as ones. If I could
determine whether a chip was an '84 versus "something else" before I program-
med it that would help greatly in avoiding this kind of disaster.
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