/*
 * Toggle PTC6-3 in C programming language for FRDM-KL25Z
 * with Wytec EduBase.  On Wytec EduBase board, PTC6-3 are connected
 * to the four LEDs.
 * Default clock 41.94MHz is used.
 */

#include "MKL25Z4.h"

void delayMs(int n);

int main(void)
{
    /* enable PTC 6-3 as output for LEDs */
    SIM->SCGC5 |= 0x800;        /* enable clock to Port C */
    PORTC->PCR[3] = 0x100;      /* make PTC3 pin as GPIO */
    PORTC->PCR[4] = 0x100;      /* make PTC4 pin as GPIO */
    PORTC->PCR[5] = 0x100;      /* make PTC5 pin as GPIO */
    PORTC->PCR[6] = 0x100;      /* make PTC6 pin as GPIO */
    PTC->PDDR |= 0x78;          /* make PTC6-3 as output pin */

    for (;;)
    {
        PTC->PCOR = 0x50;       /* turn off PTC6, 4 */
        PTC->PSOR = 0x28;       /* turn on PTC5, 3 */
        delayMs(500);
        PTC->PCOR = 0x28;       /* turn off PTC5, 3 */
        PTC->PSOR = 0x50;       /* turn on PTC6, 4 */
        delayMs(500);
    }
}

// delay n milliseconds (41.94MHz CPU clock)
void delayMs(int n)
{
    int i, j;
    for(i = 0 ; i < n; i++)
        for(j = 0; j < 7000; j++)
            {}  /* do nothing */
}