/* www.MicroDigitalEd.com
 * p5_5.c Toggling green LED using Timer32 delay

 * This program uses Timer32 to generate one second delay to
 * toggle the green LED.
 * Master clock is running at 3 MHz. Timer32 is configure
 * to count down from 3000-1 to give a 1 ms delay.
 * For every 1000 delays (1 ms * 1000 = 1 sec), toggle the
 * green LED once.  The green LED is connected to P2.1.
 *
 * Tested with Keil 5.20 and MSP432 Device Family Pack V2.2.0
 * on XMS432P401R Rev C.
 */

#include "msp.h"

void delayMs(int n);

int main(void) 
{    
    /* initialize P2.1 for green LED */
    P2->SEL1 &= ~2;         /* configure P2.1 as simple I/O */
    P2->SEL0 &= ~2;
    P2->DIR |= 2;           /* P2.1 set as output */

    while (1) {
        P2->OUT ^= 2;       /* toggle green LED */
        delayMs(1000);      /* delay 1000 ms */
    }
}

void delayMs(int n) 
{
    int i;

    TIMER32_1->LOAD = 3000 - 1; /* reload with number of clocks per millisecond */
    /* no prescaler, periodic wrapping mode, disable interrupt, 32-bit timer. */
    TIMER32_1->CONTROL = 0xC2;

    for(i = 0; i < n; i++) {
        while((TIMER32_1->RIS & 1) == 0); /* wait until the RAW_IFG is set */
        TIMER32_1->INTCLR = 0;            /* clear RAW_IFG flag */
    }
}