Tough PIC

[Art]

What would be the first problem with overclocking?
I don't think it would be heat.
Maybe reading it's own program memory to execute the program it's running?

Have run 16Fs at 25MHz many times here.

[Demon]

The biggest danger when overclocking a PC cpu is overheating. I don't see why it would be any different with a PIC.

Maybe we should liquid cool a PIC and see how fast it can run?

Robert

[Art]

You could cool one with a peltier device, but I doubt you could run it fast enough to get it hot.
PC CPUs don't have to read internal memory.
Pics are more than a CPU, but certainly Do go screwy when the outside environment heats up...

I have a 16F84A running in a vehicle that goes haywire in the heat every time (digital speedometer),
but resumes as normal when the vehicle cools down without needing any reset.
The 16F877A does not seem as fragile though (so far).

I'm still guessing it's the internal interface between it's core and internal memory that would fail.
Not that my theory could be tested. It's not like the CPU can be isolated to do anything without
using it's program memory.

[Demon]

CPUs do read internal cache, that may be technically equivalent to ram.

If I'm not mistaken, isn't the A series for automotive applications?
EDIT: Nevermind, I think it's low voltage programming.

Robert

[Art]

I meant flash memory where the program is stored in a pic.
The 16f84 I have had running a speedometer in a car for a few years always goes batty if the cab gets hot.
The chip is running, but the value displayed is all over the place.
This isn't any sort of proof that the chip is failing to read it's program memory though.
It could be any number of things like the program counter jumping all overt the place, but flash is still my guess.

[Demon]

What would be the first problem with overclocking?
I don't think it would be heat.
...

Art, was rereading this thread and realized I should have been more specific:

No problem with heat if you play with clock speeds only, the problem is when you increase voltage to keep the chip running. That's when you run into "opinions" from guys called Fourrier, Joule, Ohm, Watt and company.

Watts = volts x amps

All that extra energy has to go somewhere.

[Art]

If you ever have some hobby time to waste, set a 12C509 to toggle an LED every second,
use it's internal clock, and connect a high value potentiometer between the pic and a 12 Volt supply.
Yeah, HEAT, but result was no less than impressive