/* p7_5.c Use DAC to generate a saw tooth waveform

 * This program uses a for loop to generate a saw tooth
 * waveform output through a DAC. An 8-bit parallel input
 * DAC (TLC7524) is connected to P4. The DAC input latch
 * is put in transparent mode by grounding /CS and /WR.
 *
 * 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) {
    int i;

    /* Configure P4 as output */
    P4->SEL0 &= ~0xFF;
    P4->SEL1 &= ~0xFF;
    P4->DIR |= 0xFF;

    while (1) {
        for (i = 0; i < 0xFF; i++) {
            /* write value of i to DAC0 */
            P4->OUT = i;
            delayMs(1);         /* delay 1ms */
        }
    }
}

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

    for (j = 0; j < n; j++)
        for (i = 750; i > 0; i--);      /* Delay 1 ms */
}