ATMEGA4809 TCA0 Frequency Waveform Generation

#include <avr/io.h>

int main(void)

{

  // Select division by 2 for Prescaler: CLK_PER = CLK_MAIN / 2

  _PROTECTED_WRITE(CLKCTRL.MCLKCTRLB, 0x01);

  // Select OSC20M for the Main Clock (CLK_MAIN)

  _PROTECTED_WRITE(CLKCTRL.MCLKCTRLA, 0x00);

  // Wait while OSC20M is undergoing a switch.

  while(CLKCTRL.MCLKSTATUS & (1<<0));

  // Set TCA0 pins on PC[5:0]  

  PORTMUX.TCAROUTEA = 0x02;

  // Set PC0  as Output

  PORTC.DIR |= PIN0_bm;

  // Set CMP0EN=1 (output WO0 will be available on PC0) and WGMODE=0x1 (FRQ)

  TCA0.SINGLE.CTRLB = 0x11;

  // Set Timer to ~1s (8.000.000 / (1024*0x1E84)

  TCA0.SINGLE.CMP0BUF = 0x1E84;

  // Clear Counter

  TCA0.SINGLE.CNT = 0x0000;

  // Set fCLK_PER/1024 and Enable TCA=

  TCA0.SINGLE.CTRLB = 0x0F; //

  while(1);

}