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I am using the ATMEL SAM3x8e chip on an Arduino Due. I want to generate two pulses of frequency 100 kHz of the pattern shown below (1 period shown). For this I used TIOA8 and TIOA0 lines in the UPDOWN_RC mode and UP_RC mode. I see that the blue wave is very similar to an example waveform on TIOA shown on Pg.870 of the ATMEL datasheet. enter image description here enter image description here

My code is as follows, but I don't see any outputs on any of the two pins. What am I missing here? I deliberately didn't include the TCx_Handler() functions since I only want to generate the pulses and don't need any actions on interrupts.

void setup(){

 //Waveform on TIOA8 i.e TC2 Ch2, pin no Port D.7 pin D11
  PMC->PMC_PCER1 |= PMC_PCER1_PID35;
  PIOD->PIO_PDR |= PIO_PDR_P7; //Disable GPIO on D.7
  PIOD->PIO_ABSR |= PIO_PD7B_TIOA8;

  TC2->TC_CHANNEL[2].TC_CMR = TC_CMR_TCCLKS_TIMER_CLOCK1
                         | TC_CMR_WAVE
                         | TC_CMR_WAVESEL_UP_RC
                         | TC_CMR_ACPA_CLEAR
                         | TC_CMR_ACPC_SET;

  TC2->TC_CHANNEL[2].TC_RC = 420; //100 kHz frequency, sawtooth waveform
  TC2->TC_CHANNEL[2].TC_RA = 218; //Calculated corresponding to RC

    ////////////////////////////////////////////////////

    //Waveform on TIOA0 FOR SWITCH S1
  PMC->PMC_PCER0 |= PMC_PCER0_PID27; //TC0 CH0
  PIOB->PIO_PDR |= PIO_PDR_P25; //Disable GPIO on B.25
  PIOB->PIO_ABSR |= PIO_ABSR_P25;

  TC0->TC_CHANNEL[0].TC_CMR = TC_CMR_ACPA_TOGGLE |
                          TC_CMR_WAVE |
                          TC_CMR_WAVESEL_UPDOWN_RC |
                          TC_CMR_TCCLKS_TIMER_CLOCK1;
                           
  }

  void loop(){}
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  • \$\begingroup\$ Can you be more clear about what you are trying to accomplish? Your blue line just shows a single pulse, and your orange line only shows a transition. How often do you need to send pulses? How precise is the timing requirement? Why not just bang in a delayMicroseconds() around a couple of digitalWrite()s? \$\endgroup\$
    – Matt S
    Commented Dec 21, 2022 at 2:26

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