/* p2_7.c Toggling LED in C references registers by addresses.
 * This program toggles red LED for 0.5 second ON and 0.5 second OFF.
 * The red LED is connected to P1.0.
 * The LEDs are high active (a '1' turns ON the LED).
 *
 * Tested with Keil 5.20 and MSP432 Device Family Pack V2.2.0.
 *
 * www.microDigitalEd.com
 */

#define P1_DIR (*((volatile unsigned char*)0x40004C04))
#define P1_OUT (*((volatile unsigned char*)0x40004C02))

void delayMs(int n);

int main(void) 
{
	P1_DIR |= 1;            /* P1.0 set as output */

  while (1) 
	{
		P1_OUT |= 1;        /* turn on P1.0 red LED */
    delayMs(500);
    P1_OUT &= ~1;       /* turn off P1.0 red LED */
    delayMs(500);
	}
}

/* delay milliseconds when system clock is at 3 MHz */
void delayMs(int n) {
    int i, j;

    for (j = 0; j < n; j++)
        for (i = 250; i > 0; i--);      /* Delay 1 ms */
}