/* p11_1.c Using TC5 for PWM Output 
 *
 * This program uses TC5 to generate PWM waveform outputs.
 * The GCLK_TC5 is running at 1 MHz. Prescaler is not used so
 * the timer counter clock is 1 MHz as well.
 * TC5 is set up to run 16-bit Match PWM mode, in
 * which the counter counts up to CC0 as the TOP value and wraps
 * around. The channel 1 output is set when on wraparound
 * and clear on match of CC1.
 * CC0 is set to 16,666-1 which gives the output frequency
 * 1,000,000 / 16,666 = 60 Hz.
 * CC1 is set to 1/3 of the value of CC0 so that the outputs of
 * channel 1 has 33.3% duty cycle.
 * PB11 is used for TC5 output channel 1 (TC5/WO[1]).
 *
 * Tested with Atmel Studio 7 v7.0.1006 and Keil MDK-ARM v5.21a.
 */

#include "samd21.h"

unsigned char* ARRAY_PORT_PINCFG1 = (unsigned char*)&REG_PORT_PINCFG1;
unsigned char* ARRAY_PORT_PMUX1 = (unsigned char*)&REG_PORT_PMUX1;

int main (void) {
    REG_GCLK_CLKCTRL = 0x401C;      /* GCLK0 -> TC4/TC5 */
    REG_PM_APBCMASK |= 0x00002000;  /* Enable TC5 Clock in PM */
    REG_TC5_CTRLA = 1;              /* Software Reset */
    while (REG_TC5_CTRLA & 1) {}    /* wait till out of reset */
    REG_TC5_CTRLA = 0x0060;         /* no prescaler, 16-bit, MPWM */
    REG_TC5_COUNT16_CC0 = 16666 - 1; /* match value 0 */
    REG_TC5_COUNT16_CC1 = 5555 - 1; /* match value 1 */
    REG_TC5_CTRLA |= 2;             /* enable */

    ARRAY_PORT_PINCFG1[11] |= 1;    /* make PB11 output for TC5 */
    ARRAY_PORT_PMUX1[5] = 0x40;     /* PB11 = TC5*/
        
    while(1) {
    }
}