[讨论] 今天小用了一下ECAP的捕获功能

void InitECapture()
{
   ECap1Regs.ECEINT.all = 0x0000;             // Disable all capture interrupts
   ECap1Regs.ECCLR.all = 0xFFFF;              // Clear all CAP interrupt flags
   ECap1Regs.ECCTL1.bit.CAPLDEN = 0;          // Disable CAP1-CAP4 register loads
   ECap1Regs.ECCTL2.bit.TSCTRSTOP = 0;        // Make sure the counter is stopped
  
   // Configure peripheral registers
  // ECap1Regs.ECCTL2.bit.CONT_ONESHT = 1;      // One-shot
 /*  ECap1Regs.ECCTL2.bit.CONT_ONESHT = EC_CONTINUOUS;
   ECap1Regs.ECCTL2.bit.STOP_WRAP =
 //  ECap1Regs.ECCTL2.bit.STOP_WRAP = 3;        // Stop at 4 events
   ECap1Regs.ECCTL1.bit.CAP1POL = 1;          // Falling edge
   ECap1Regs.ECCTL1.bit.CAP2POL = 0;          // Rising edge
   ECap1Regs.ECCTL1.bit.CAP3POL = 1;          // Falling edge
   ECap1Regs.ECCTL1.bit.CAP4POL = 0;          // Rising edge
   ECap1Regs.ECCTL1.bit.CTRRST1 = 1;          // Difference operation        
   ECap1Regs.ECCTL1.bit.CTRRST2 = 1;          // Difference operation        
   ECap1Regs.ECCTL1.bit.CTRRST3 = 1;          // Difference operation        
   ECap1Regs.ECCTL1.bit.CTRRST4 = 1;          // Difference operation        
   ECap1Regs.ECCTL2.bit.SYNCI_EN = 1;         // Enable sync in
   ECap1Regs.ECCTL2.bit.SYNCO_SEL = 0;        // Pass through
   ECap1Regs.ECCTL1.bit.CAPLDEN = 1;          // Enable capture units
*/
// Code snippet for CAP mode Delta Time, Rising and Falling
// edge triggers
// Initialization Time
//=======================
// ECAP module 1 config
 ECap1Regs.ECCTL1.bit.CAP1POL = EC_RISING;
 ECap1Regs.ECCTL1.bit.CAP2POL = EC_FALLING;
 ECap1Regs.ECCTL1.bit.CAP3POL = EC_RISING;
 ECap1Regs.ECCTL1.bit.CAP4POL = EC_FALLING;
 ECap1Regs.ECCTL1.bit.CTRRST1 = EC_DELTA_MODE;
 ECap1Regs.ECCTL1.bit.CTRRST2 = EC_DELTA_MODE;
 ECap1Regs.ECCTL1.bit.CTRRST3 = EC_DELTA_MODE;
 ECap1Regs.ECCTL1.bit.CTRRST4 = EC_DELTA_MODE;
 ECap1Regs.ECCTL1.bit.CAPLDEN = EC_ENABLE;
 ECap1Regs.ECCTL1.bit.PRESCALE = EC_DIV1;
 ECap1Regs.ECCTL2.bit.CAP_APWM = EC_CAP_MODE;
 ECap1Regs.ECCTL2.bit.CONT_ONESHT = EC_CONTINUOUS;
 ECap1Regs.ECCTL2.bit.SYNCO_SEL = EC_SYNCO_DIS;
 ECap1Regs.ECCTL2.bit.SYNCI_EN = EC_DISABLE;
 ECap1Regs.ECCTL2.bit.TSCTRSTOP = EC_RUN; // Allow TSCTR to run

  //  ECap1Regs.ECCTL2.bit.TSCTRSTOP = 1;        // Start Counter
  //  ECap1Regs.ECCTL2.bit.REARM = 1;            // arm one-shot
  //  ECap1Regs.ECCTL1.bit.CAPLDEN = 1;          // Enable CAP1-CAP4 register loads
    ECap1Regs.ECEINT.bit.CEVT4 = 1;            // 4 events = interrupt

}

interrupt void ecap1_isr(void)
{

   // Cap input is syc'ed to SYSCLKOUT so there may be
   // a +/- 1 cycle variation
/*   
   if(ECap1Regs.CAP2 > EPwm3Regs.TBPRD*2+1 || ECap1Regs.CAP2 < EPwm3Regs.TBPRD*2-1)
   {
       Fail();
   }

   if(ECap1Regs.CAP3 > EPwm3Regs.TBPRD*2+1 || ECap1Regs.CAP3 < EPwm3Regs.TBPRD*2-1)
   {
       Fail();
   }
  
   if(ECap1Regs.CAP4 > EPwm3Regs.TBPRD*2+1 || ECap1Regs.CAP4 < EPwm3Regs.TBPRD*2-1)
   {
       Fail();
   }  

   ECap1IntCount++;

   if(EPwm3TimerDirection == EPWM_TIMER_UP)
   {
        if(EPwm3Regs.TBPRD < PWM3_TIMER_MAX)
        {
           EPwm3Regs.TBPRD++;
        }
        else
        {
           EPwm3TimerDirection = EPWM_TIMER_DOWN;
           EPwm3Regs.TBPRD--;
        }
   }
   else
   {
        if(EPwm3Regs.TBPRD > PWM3_TIMER_MIN)
        {
           EPwm3Regs.TBPRD--;
        }
        else
        {
           EPwm3TimerDirection = EPWM_TIMER_UP;
           EPwm3Regs.TBPRD++;
        }
   }  
*/
// Run Time ( e.g. CEVT1 triggered ISR call)
//==========================================
// Note: here Time-stamp directly represents the Duty cycle values.
 DutyOnTime1 = ECap1Regs.CAP2; // Fetch Time-Stamp captured at T2
 DutyOffTime1 = ECap1Regs.CAP3; // Fetch Time-Stamp captured at T3
 DutyOnTime2 = ECap1Regs.CAP4; // Fetch Time-Stamp captured at T4
 DutyOffTime2 = ECap1Regs.CAP1; // Fetch Time-Stamp captured at T1 
 Period1 = DutyOnTime1 + DutyOffTime1;
 Period2 = DutyOnTime2 + DutyOffTime2;

   ECap1PassCount++;

 //  ECap1Regs.ECCLR.bit.CEVT1 = 1;
  // ECap1Regs.ECCLR.bit.INT = 1;
   ECap1Regs.ECCTL2.bit.REARM = 1;

   // Acknowledge this interrupt to receive more interrupts from group 4
   ECap1Regs.ECCLR.bit.CEVT4  = 1;
   ECap1Regs.ECCLR.bit.INT = 1;
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP4;
}
还是有小插曲应该清除CEVT4的标志位的，偶开始清了CEVT1的，发现进了中断后就一直反复进中断。

后来一查就发现了。

大家别像偶一样粗心。