Interrupt Priority PIC18F67K22

GusA · Joined: 28 Mar 2020 Posts: 5 Location: York, PA

How do I configure interrupt priorities (IPEN = 1) for the pic18f67k22 microcontroller? I am using the PCWH compiler.
I do not see it on the IDE project wizard, or find it on the CCS C compiler manual.

Also, my code includes use of the modbus rtu driver. It is factory configured to interrupt on RDA from the uart. Can it be re-configured to use hi/lo interrupt priority and set as low priority?

Thanks!

Ttelmah · Joined: 11 Mar 2010 Posts: 19215

It is in the manual.

Add the line:

#device HIGH_INTS=TRUE

near the start of your code (just after the include for the processor).
This turns on IPEN.

Then declare your INT_RDA with:

#INT_RDA HIGH

This will then be a high priority interrupt, with separate locations used
to store the regsiters.

One caveat. INT_EXT does not have a priority control bit, and if this
is used it will always be a high priority interrupt.