TMS320F28377D 的ECAP 模块 测试方波的频率和占空比

您可以参考下C2000WARE内例程的设置

C2000Ware_2_00_00_02\device_support\f2837xd\examples\cpu1\ecap_capture_pwm

该例程是one-shot的

//
// InitECapture - Initialize ECAP1 configurations
//
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.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

   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
}

//
// ecap1_isr - ECAP1 ISR
//              Cap input is syc'ed to SYSCLKOUT so there may be
//              a +/- 1 cycle variation
//
__interrupt void ecap1_isr(void)
{
   if(ECap1Regs.CAP2 > EPwm3Regs.TBPRD*4+4 ||
      ECap1Regs.CAP2 < EPwm3Regs.TBPRD*4-4)
   {
       Fail();
   }

   if(ECap1Regs.CAP3 > EPwm3Regs.TBPRD*4+4 ||
      ECap1Regs.CAP3 < EPwm3Regs.TBPRD*4-4)
   {
       Fail();
   }

   if(ECap1Regs.CAP4 > EPwm3Regs.TBPRD*4+4 ||
      ECap1Regs.CAP4 < EPwm3Regs.TBPRD*4-4)
   {
       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++;
        }
   }

   ECap1PassCount++;

   ECap1Regs.ECCLR.bit.CEVT4 = 1;
   ECap1Regs.ECCLR.bit.INT = 1;
   ECap1Regs.ECCTL2.bit.REARM = 1;

   //
   // Acknowledge this __interrupt to receive more __interrupts from group 4
   //
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP4;
}