/* p6_5.c Toggling red and green LED using TPM0 and TPM1 interrupts

 This program is modified from p5-5 and p5-6 but instead of using polling, the timeout interrupts are used.
 TPM1 is configured to run twice the frequency of TPM0.
 The infinite loop in main blinks the blue LED. The TPM0 interrupt handler toggles the red LED and the TPM1 green LED. */

#include <MKL25Z4.H>

void delayMs(int n);

int main (void) {
    __disable_irq();        /* global disable IRQs */

    SIM->SCGC5 |= 0x400;        /* enable clock to Port B */
    SIM->SCGC5 |= 0x1000;       /* enable clock to Port D */
    PORTB->PCR[18] = 0x100;     /* make PTB18 pin as GPIO */
    PTB->PDDR |= 0x40000;       /* make PTB18 as output pin */
    PORTB->PCR[19] = 0x100;     /* make PTB19 pin as GPIO */
    PTB->PDDR |= 0x80000;       /* make PTB19 as output pin */
    PORTD->PCR[1] = 0x100;      /* make PTD1 pin as GPIO */
    PTD->PDDR |= 0x02;          /* make PTD1 as output pin */
    
    SIM->SOPT2 |= 0x01000000;   /* use MCGFLLCLK as timer counter clock */
    
    SIM->SCGC6 |= 0x01000000;   /* enable clock to TPM0 */  
    TPM0->SC = 0;               /* disable timer while configuring */
    TPM0->SC = 0x07;            /* prescaler /128 */
    TPM0->MOD = 0xFFFF;         /* max modulo value */
    TPM0->SC |= 0x80;           /* clear TOF */
    TPM0->SC |= 0x40;           /* enable timeout interrupt */
    TPM0->SC |= 0x08;           /* enable timer */
    NVIC->ISER[0] |= 0x00020000;    /* enable IRQ17 (bit 17 of ISER[0]) */

    SIM->SCGC6 |= 0x02000000;   /* enable clock to TPM1 */
    TPM1->SC = 0;               /* disable timer while configuring */
    TPM1->SC = 0x07;            /* prescaler /128 */
    TPM1->MOD = 0x7FFF;         /* half of the max modulo value */
    TPM1->SC |= 0x40;           /* enable timeout interrupt */
    TPM1->SC |= 0x08;           /* enable timer */
    NVIC->ISER[0] |= 0x00040000;    /* enable IRQ18 (bit 18 of ISER[0]) */
    
    __enable_irq();         /* global enable IRQs */

    while (1) {
        PTD->PTOR = 0x02;       /* toggle blue LED */
        delayMs(1500);
    }
}

void TPM0_IRQHandler(void) {
    PTB->PTOR = 0x40000;        /* toggle red LED */
    TPM0->SC |= 0x80;           /* clear TOF */
}

void TPM1_IRQHandler(void) {
    PTB->PTOR = 0x80000;        /* toggle green LED */
    TPM1->SC |= 0x80;           /* clear TOF */
}

/* Delay n milliseconds
 * The CPU core clock is set to MCGFLLCLK at 41.94 MHz in SystemInit().
 */
void delayMs(int n) {
    int i;
    int j;
    for(i = 0 ; i < n; i++)
        for (j = 0; j < 7000; j++) {}
}