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barkerben
- 18th January 2005, 20:11
Hi,

I had a quick question about 'special' pins on the PIC, such as the interrupt pins, or the USART pins.

If we are not making use of these special features, we can forget the pins are different from any others. If we are using them, and have enabled all the neccesary control registers, then does it matter, for instance, whether we set the pins to high or low, input or output?

In other words, once the special status of the pin has been enabled, does this overide anything else we try to do to it.

Should I set the TRIS registers just to be safe to ensire that I can't, for instance, send the pin high that is being used to receive hardware usart, or is this all done automatically somewhere anyway...?


Cheers,


Ben

Archilochus
- 18th January 2005, 22:40
Hi Ben,
Each special function pin / port will have different attributes. The only way to be sure of proper operation is to read and re-read the specs for the specific part.
Then - if you're like me - you'll kill off a few chips while 'experimenting', before figuring out how it's pins / ports should be configured :-O

I always (attempt to) set every special function register to a 'known' state at the beginning of any code to try and avoid any conflicts later on in the code.

Arch