ECAP6 Interrupt

Sam DeBruin

Other Parts Discussed in Thread: CONTROLSUITE

Hello,

I am trying to use ECAP6 to capture the period and duty cycle of an externally generated PWM. I have assigned the pin (PH1 - GPIO49) to the C28, enabled the interrupts and polarities, and have enabled the clock. I have two problems:

1) interrupts do not generate, and

2) when I pause the debugger, CAP1, CAP2, CAP3, CAP4, and TSCTR all have the same value (which increases between each pause).

Code is copied below:

interrupt void ecap6_isr(void) {
	unsigned long val = ECap6Regs.CAP2;
	ECap6Regs.ECCLR.all = 0xFFFF;
	PieCtrlRegs.PIEACK.all = PIEACK_GROUP4;
	return;
}

void ecap_init() {

	SysCtrlRegs.PCLKCR1.bit.ECAP6ENCLK = 1;

    EALLOW;
    GpioCtrlRegs.GPBQSEL2.bit.GPIO49 = 0;   // Synch to SYSCLKOUT GPIO49 (CAP6)
    GpioCtrlRegs.GPBMUX2.bit.GPIO49 = 1;    // Configure GPIO49 as CAP6
    GpioTripRegs.GPTRIP12SEL.bit.GPTRIP12SEL = 49;   // Configure GPIO49 as CAP6
    EDIS;

    // Register interrupt
    EALLOW;
    PieVectTable.ECAP6_INT = &ecap6_isr;
    EDIS;

    // Initialize capture module
    ECap6Regs.ECEINT.all = 0x0000;            // Disable all capture interrupts
    ECap6Regs.ECCLR.all = 0xFFFF;             // Clear all CAP interrupt flags
    ECap6Regs.ECCTL1.bit.CAPLDEN = 0;         // Disable CAP1-CAP4 register
                                              // loads
    ECap6Regs.ECCTL2.bit.TSCTRSTOP = 0;       // Make sure the counter is
                                              // stopped

    ECap6Regs.ECCTL1.bit.CAP1POL = 0;
    ECap6Regs.ECCTL1.bit.CAP2POL = 1;
    ECap6Regs.ECCTL1.bit.CAP3POL = 0;
    ECap6Regs.ECCTL1.bit.CAP4POL = 1;

    ECap6Regs.ECCTL1.bit.CTRRST1 = 0;
    ECap6Regs.ECCTL1.bit.CTRRST2 = 1;
    ECap6Regs.ECCTL1.bit.CTRRST3 = 0;
    ECap6Regs.ECCTL1.bit.CTRRST4 = 1;

    ECap6Regs.ECCTL1.bit.CAPLDEN = 1;         // Enable capture units
    ECap6Regs.ECCTL1.bit.PRESCALE = 0;
    ECap6Regs.ECCTL2.bit.CAP_APWM = 0;			// Capture mode
    ECap6Regs.ECCTL2.bit.CONT_ONESHT = 0;
    ECap6Regs.ECCTL2.bit.SYNCO_SEL = 2;
    ECap6Regs.ECCTL2.bit.SYNCI_EN = 0;

    ECap6Regs.ECCTL2.bit.TSCTRSTOP = 1;       // Start Counter
    ECap6Regs.ECEINT.bit.CEVT4 = 1;

    // Enable CPU INT4
	IER |= M_INT4;

	// Enable eCAP INTn in the PIE
	PieCtrlRegs.PIEIER4.bit.INTx1 = 1;

	return;
}

I believe the problems may be related, but I have not been able to find the problem. Does anybody have any recommendations?

Thank you

Sam

over 12 years ago

0 Sam DeBruin over 12 years ago

Prodigy 130 points

I should say, as well, that InitSysCtrl, InitPieCtrl, and InitPieVectTable are called before ecap_init, and EINT and ERTM after

0 Brett Larimore over 12 years ago in reply to Sam DeBruin

TI__Guru 57255 points

Sam,

Hopefully you have gotten further, but I do have a few comments:

PieCtrlRegs.PIEIER4.bit.INTx1 = 1; should be PieCtrlRegs.PIEIER4.bit.INTx6 = 1; according to the PIE interrupt vector table (Table 1-12 in the F28m35x TRM). Everything else appears to be close to correct.
Based on your code I would assume you have but if not, try the ecap_capture_pwm project within controlSUITE: \controlSUITE\device_support\f28m35x\vZZZ\F28M35x_examples_Control\ecap_capture_pwm\c28\

Thank you, Brett

0 Igor Gorbachev over 12 years ago in reply to Brett Larimore

Guru 20525 points

Dear Brett!

Excuse me, but could you please comment this thread (there is strange problem with CLA examples, I have tried all and I have not ideas more) http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/308954.aspx.

Many thanks,

Igor

C2000™︎ microcontrollers

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ECAP6 Interrupt