how may year did PIC remains

[mogiz]

I want to ask if any body know how many
time did the programs in PIC stay in the circuit
without they being erased or the PIC damage

the reason for this question is know how many time did the pic stay in a certain
circuit without it stop work

the designer and the company afriad that their circuit stop working suddenly

for example if I leave a certain circuit supported with PIC for a year
and you supply it with supply source >>>>>
Did it stop work or not

 

[throwaway18]

I know of about ten windowed PIC microcontrollers that have been in service for about 8 years without problems at room temperature with metalised labels over the quartz window.

I think the one-time-programmable versions are the same die in a plastic package (stored charge type memory).

High temperature is likely to cause the program memory to fail faster.

I have not used the eeprom data memory in PIC's

The program memory is likely to fail one bit at a time. You could use a pic that can read it's own program memory, put two copies of the main program in the pic and have a small routine that checksums both copies at startup. If one copy is bad then use the other copy and turn on a "Unit faulty- Call service engineer" LED.

 

[mogiz]

thank you for your information

Added after 4 minutes:

I ask how many can pic in the circuit left without
the need of replacing program or reprogram the pic
again in at room temperture
1-in case the circuit work continuestly
2-in the case the circiut left (store ) the worked

 

[BeeBop]

You shouldn't have to worry about replacing the code. The memory wears out from being written to, not read from. If you have an old circuit that has not been powered for a long time, it should run as well as it last did when it was powered. If the circuit has power, and is running, this should not wear it out either. The time when the micro will fail is when you are trying to write to it, and not all locations can be written. Even this, I suspect, is very rare.
Hope that answers your question.
Regards,
Robert

 

[latecomer]

Hello,
I have 48 PIC16C622A controllers working in a panel for about 16 hrs a day since the year 1999. Today is March 23rd, 2006. Till now no PIC in that panel has failed. They are working fine at room temperature (Depending on weather conditions, the temperature varies between 12 deg centigrade to 45 deg centigrade)

 

[domble]

We've been using PICs since about 1990, not in large quantities, only tens or hundreds each year. Some used in nasty conditions (relatively high temperatures). Don't recall having one fail yet, customers usually tell us when something breaks! Just switched on a 5 year old PIC based product and it's fine.

dom.

 

[mogiz]

thank you
the above two post are good real implementation