nested interrupts Epwm and timer1

Hi Nayana,

This link would give you all info on Interrupt Nesting:

http://processors.wiki.ti.com/index.php/Interrupt_Nesting_on_C28x

Regards,

Gautam

Hey Gautam,

I followed the same procedure as mentioned in the link, But I did not get the expected output.

In the following example instead of group2 interrupt i am using group 3. I need to disable timer1 interrupt(lower group interrupt should not interrupt higher priority interrupt) within ePWM interrupt. please help me with that.

// C28x ISR Code
//
// Enable nested interrupts 
//
//
interrupt void EPWM1_TZINT_ISR(void) 
{
    uint16_t TempPIEIER;
    TempPIEIER = PieCtrlRegs.PIEIER2.all; // Save PIEIER register for later
    IER |= 0x002;                         // Set global priority by adjusting IER
    IER &= 0x002;                         
    PieCtrlRegs.PIEIER2.all &= 0x0002;    // Set group priority by adjusting PIEIER2 to allow INT2.2 to interrupt current ISR
    PieCtrlRegs.PIEACK.all = 0xFFFF;      // Enable PIE interrupts
    asm("       NOP");                    // Wait one cycle
    EINT;                                 // Clear INTM to enable interrupts
    //
    // Insert ISR Code here.......
    // for now just insert a delay
    //
    for(i = 1; i <= 10; i++) {}
    //
    // Restore registers saved:
    //
    DINT;
    PieCtrlRegs.PIEIER2.all = TempPIEIER;
}
#endif

Thanks & Regards,

Nayana

That's very strange that you're not getting the expected output. Do also go through this link for detailed info on nested interrupts:

http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/311734.aspx

Regards,

Gautam

Hi Gautam,

    This is my code,

ePWM 1 period is 62 uSec and CPU timer1 period is 100 uSec

interrupt void epwm1_timer_isr(void)
{

   GpioDataRegs.GPASET.bit.GPIO22=1;
   for(i=10; i>0 ; i--)                        //10us delay
   {
           for(j=7; j>0; j--)
           {
              k++;
           }
   }
   GpioDataRegs.GPACLEAR.bit.GPIO22=1;
   //EPwm1TimerIntCount++;

   // Clear INT flag for this timer
   EPwm1Regs.ETCLR.bit.INT = 1;

   // Acknowledge this interrupt to receive more interrupts from group 3
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}

interrupt void cpu_timer1_isr(void)
{

  GpioDataRegs.GPASET.bit.GPIO23=1;
  for(i=25; i>0 ; i--)                            //25us delay
       {
           for(j=7; j>0; j--)
           {
               k++;
           }
       }
  GpioDataRegs.GPACLEAR.bit.GPIO23=1;
   //CpuTimer1.InterruptCount++;

   // The CPU acknowledges the interrupt.
   EDIS;

}
 but epwm pulse is getting delayed because of timer.

If i try to incorporate code given in link i am not getting the output at all. I tried attaching the screen shots but getting error.

Regards,

nayana