Programming TM4C Tiva C Cortex-M4 Timers to count events
//Author : cortex-m.com
//Function : Periodic mode milliseconds delay
#include "TM4C123.h" // Device header
#include<stdint.h>
void Timer3A_countCapture_init(void);
int Timer3A_countCapture(void);
uint32_t count;
int main()
{
Timer3A_countCapture_init();
while(1){
count=0;
count = Timer3A_countCapture();
}
}
void Timer3A_countCapture_init(void)
{
SYSCTL->RCGCTIMER |= 8; /* enable clock to Timer Block 3 */
SYSCTL->RCGCGPIO |= 2; /* enable clock to PORTB */
GPIOB->DIR &= ~0x04; /* make PB2 an input pin */
GPIOB->DEN |= 0x04; /* make PB2 a digital pin */
GPIOB->AFSEL |= 0x04; /* enable alternate function on PB2 */
GPIOB->PCTL &= ~0x00000F00; /* configure PB2 as T3CCP0 pin */
GPIOB->PCTL |= 0x00000700;
TIMER3->CTL &= ~1; /* disable TIMER3A during setup */
TIMER3->CFG = 4; /* configure as 16-bit timer mode */
TIMER3->TAMR = 0x13; /* up-count, edge-count, capture mode */
TIMER3->TAMATCHR = 0xFFFF; /* set the count limit */
TIMER3->TAPMR = 0xFF; /* to 0xFFFFFF with prescaler */
TIMER3->CTL &= ~0xC; /* capture the rising edge */
TIMER3->CTL |= 1; /* enable timer3A */
}
int Timer3A_countCapture(void)
{
return TIMER3->TAR;
}