Program1 : Periodic mode milliseconds delay
//Author : cortex-m.com
//Function : Periodic mode milliseconds delay
#include "TM4C123.h" // Device header
void timer0A_delayMs(int ttime);
int main (void)
{
/* enable clock to GPIOF at clock gating control register */
SYSCTL->RCGCGPIO |= 0x20;
/* enable the GPIO pins for the LED (PF3, 2 1) as output */
GPIOF->DIR = 0x0E;
/* enable the GPIO pins for digital function */
GPIOF->DEN = 0x0E;
while(1)
{
GPIOF->DATA = 2; /* turn on red LED */
timer0A_delayMs(500); /* TimerA 500 msec delay */
GPIOF->DATA = 0; /* turn off red LED */
timer0A_delayMs(500); /* TimerA 500 msec delay */
}
}
/* multiple of millisecond delay using periodic mode */
void timer0A_delayMs(int ttime)
{
int i;
SYSCTL->RCGCTIMER |= 1; /* enable clock to Timer Block 0 */
TIMER0->CTL = 0; /* disable Timer before initialization */
TIMER0->CFG = 0x04; /* 16-bit option */
TIMER0->TAMR = 0x02; /* periodic mode and down-counter */
TIMER0->TAILR = 16000 - 1; /* Timer A interval load value register */
TIMER0->ICR = 0x1; /* clear the TimerA timeout flag*/
TIMER0->CTL |= 0x01; /* enable Timer A after initialization */
for(i = 0; i < ttime; i++) { while ((TIMER0->RIS & 0x1) == 0) ; /* wait for TimerA timeout flag */
TIMER0->ICR = 0x1; /* clear the TimerA timeout flag */
}
}