pic or avr in the industrial environments?

[kasser]

which is best when working in the industrial environments ? pic or avr mcu?
and how can I protet my circuit based on a mcu then?

thanks in advance

 

[dknguyen]

which is best when working in the industrial environments ? pic or avr mcu?
and how can I protet my circuit based on a mcu then?

thanks in advance

The "best" is very vague especially for two microcontrollers like those that can basically do the same jobs. It comes down to preference and availability (especially availability of development tools).

Optoisolate + shielding.

 

[kasser]

thank you :
but for the same application and protection (Optoisolate + shielding) for both pic,avr ,is there one better than one.
as I know there are pic chips to be one time programmable (OTP) ,
while there are no such chips in avr mcus.
since (OTP) are more reliability in industrial environments.

 

[dknguyen]

thank you :
but for the same application and protection (Optoisolate + shielding) for both pic,avr ,is there one better than one

Like I already said, no.

I know there are pic chips to be one time programmable (OTP) ,
while there are no such chips in avr mcus.
since (OTP) are more reliability in industrial environments.

I'm pretty sure there must be some OTP for AVR, otherwise how would they handle high volume applications? I am also uncertain that OTP is more reliable than flash- it is certainly less flexible and can't be used for debugging. But if AVR doesn't have OTP while PIC does, and you need it then this would be a deciding factor for you (but you already knew that right?).

But you have to decide whether you really need OTP. The cost difference between FLASH and OTP is quite small and only realy makes a difference if are you mass producing this in MASSIVELY MASSIVE quantities large enough so the cost savings make a difference? And I would think at those quantities the manufacturer would be happy to just ROM the microcontrollers for you (they must have that capability?) so that whether or not they have OTP doesn't matter. Are you going to be building thousands (or millions?) of these devices? Are you never ever going to need to update the firmware in the field? Assuming OTP is more reliable than flash, remember that OTP with buggy code is much worse than FLASH with better code (or the potential to upload fixed code). What will happen first? Your code fails? Or the memory in the hardware? Probably your code, in which case OTP's reliability advantage means nothing.

THat said, I've never heard of anyone choosing OTP over FLASH because of reliability. If OTP really is more reliable than FLASH, then the difference is probably negligible unless you plan on your device to be functional for a hundred years- and not ever get replaced by something else during that time period. Remember that the difference in reliability between revisions of your code is probably much MUCH more than the difference between the reliability of FLASH and OTP.

I don't have anything to do with the military, but I'd bet that the military equipment doesn't use OTP. Is that reliable enough for you? I don't think you would ever notice the difference between the reliability of OTP or flash.

 

[donniedj]

If you have ginuine concern about robustness, please to not rely on anyone other than the manufacture for they are the bounded by there specs and not random word of mouths.

Environmental specs in the datasheets here: www.atmel.com
Environmental specs in the datasheets here: www.microchip.com

How would anyone answer your question? They researched into the devices. What reason would you not do the same.

 

[Papabravo]

One additional point. OTP parts are actually derived from UV eraseable parts. Packaging them in plastic instead of ceramic with a quartz window is what makes them OTP. The bits are still created by storing charge on a floating gate.

I agree with the previous poster that you want to start with manufacturers reliability data and then try to find independent sources if you can. You might start with parts which are characterized over a wider temperature range than 0-70 degrees C.

Conventional wisdom is that in the industrial environment temperature is the biggie, followed perhaps by electrical fast transients. In both cases you have way more than the microprocessor to worry about.

 

[kasser]

thank you for all

 

[Gayan Soyza]

The micros that I'm using the manufacture has printed I/P on each micro controller which means "Industrial Package" that means the manufacture has accept to run in those environments.