ermmm pic32mx795f512l
i want to set up an external interrupt to wake it from sleep, to do this, i need to set the extint priority above the cpu..
but i dont know where the cpu vector is? nor what its default is.. nor if i can just set it to one below the highest and that be it.. make sense?
ta

 

what does the manual says?

 

no idea.. maybe im looking for the wrong thing.. but pic32mx795f512l datasheet doesnt mention cpu priority..

 

Get the family ref manuals. http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2612

Interrupts:
http://ww1.microchip.com/downloads/en/DeviceDoc/61108G.pdf

 

iv looked in there, thats what im saying, i think im looking for the wrong interrupt name, im looking for anything referring to cpu priority, but that must be wrong, the cpu is such a vague thing to say

 

i've been using pic24s, should be similar:

vector table is at the begin of addressable memory.
there are variety of interrupt sources, external ones are either INT0 INT1... or Change Notification.
Interrupt priority is 1..7. higher value is higher priority.

 

yeh, i was looking at the table again today, i reckon im just overcomplicating things, should try it out, and if it doesnt wake the device up properly then hit it with a hammer...

 

It would help to know what compiler you are using. Should it happen to be the C32 compiler there are library functions for this. Details can be found in the help file located at ...\Microchip\mplabc32\v2.01\doc\pic32-lib-help\INT-PLIB-Help.chm

Here's a sample of how a timer interrupt looks:

/////////////////////////////////////////////////////////////////////////////
// Function: Timer3 ISR
// Input: none
// Output: none
// Overview: increments tick counter. Tick is approx. 1 ms.
/////////////////////////////////////////////////////////////////////////////
    #define __T3_ISR    __ISR(_TIMER_3_VECTOR, ipl4)

/* */
void __T3_ISR _T3Interrupt(void)
{
    // Clear flag
    mT3ClearIntFlag();
    // do something useful
    UsefulFunction();
}

 

hi ernie.. im using c32, but the problem i thought i might have is that to wake the device up from sleep, (OSCCON SLPEN) i need to make sure that the wake up source (external interrupt) is a higher priority than the CPU...if it isnt, then it wont wake the device up,
ta for the code though, hadnt considered using a #define t make the isr easier.

 

you can assign priority to any interrupt.

void  configTimer3(void) {
  //ensure that Timer2,3 configured as separate timers.
  T2CONbits.T32 = 0;     // 32-bit mode off
  //T3CON set like this for documentation purposes.
  //could be replaced by T3CON = 0x0030
  T3CON = T3_OFF | T3_IDLE_CON | T3_GATE_OFF
          | T3_SOURCE_INT
          | T3_PS_1_256 ;  //results in T3CON= 0x0030
  //PR3 = msToU16Ticks (ISR_PERIOD, getTimerPrescale(T3CONbits)) - 1;
PR3=0xFFFF;
  TMR3  = 0;                       //clear timer3 value
  _T3IF = 0;                       //clear interrupt flag
  _T3IP = 2;                       //choose a priority
  _T3IE = 1;                       //enable the interrupt
  T3CONbits.TON = 1;               //turn on the timer
}