TM4C129ENCPDT: Timer in capture mode

HI,

  First of all, it seems you are using an older version of TivaWare as I see SYSCTL_CFG_VCO_480 in your clock configuration. Please download the latest TivaWare version as it has a example that uses Timer0 to calculate the high phase of a input. The example can be found at C:\ti\TivaWare_C_Series-2.2.0.295\examples\boards\ek-tm4c1294xl\timer_edge_capture.

I think I also see two issues. You are trying to use timer_A of Timer4 module. But you call:

TimerConfigure(TIMER4_BASE, TIMER_CFG_A_CAP_TIME_UP);

instead of:

TimerConfigure(TIMER4_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME_UP);

Second, I don't see you call IntEnable(INT_TIMER4A);

Hi,

  Please take a look at this example. It works for me. Just a heads-up, Monday is a US public holiday and my response will be delayed. 

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/fpu.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/timer.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "utils/ustdlib.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"

uint32_t g_ui32SysClock;

uint32_t g_ui32IntCount = 0;

uint32_t g_intFlag = 0;

void
InitConsole(void)
{
	// Enable GPIO port A which is used for UART0 pins.
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

	// Enable UART0 so that we can configure the clock.
	SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);


	GPIOPinConfigure(GPIO_PA0_U0RX);
	GPIOPinConfigure(GPIO_PA1_U0TX);

	// Use the internal 16MHz oscillator as the UART clock source.
	UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC);


	// Select the alternate (UART) function for these pins.
	GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

	// Initialize the UART for console I/O.
	UARTStdioConfig(0, 115200, 16000000);
}

// The interrupt handler for timer 4.

void
Timer4IntHandler(void)
{
	// Clear the timer interrupt.
	TimerIntClear(TIMER4_BASE, TIMER_CAPA_MATCH);

	g_ui32IntCount+=5;

	g_intFlag = 1;

	// The timer is automatically stopped when it reaches the match value so re-enable it here.
	TimerEnable(TIMER4_BASE, TIMER_A);
}


int
main(void)
{


	g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
			SYSCTL_OSC_MAIN |
			SYSCTL_USE_PLL |
			SYSCTL_CFG_VCO_480), 120000000);

	// UART Func Call
	InitConsole();

	UARTprintf("Timer Input Edge Example\n");

	// Enable Timer4 & GPIOM
	SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER4);
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOM);

	// Configure PM0 as the CCP0(Timer A) pin for timer 4.
	GPIOPinTypeTimer(GPIO_PORTM_BASE, GPIO_PIN_4);
	GPIOPinConfigure(GPIO_PM4_T4CCP0);

	// Enable processor interrupts.
	IntMasterEnable();

	// Configure the timers in edge count mode.
	TimerConfigure(TIMER4_BASE, (TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_COUNT_UP));
	TimerControlEvent(TIMER4_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);
	TimerLoadSet(TIMER4_BASE, TIMER_A,6);

	// Set match to 15 so that after 5 postive edges detected, generate a match interrupt
	TimerMatchSet(TIMER4_BASE, TIMER_A,5);

	// Setup the interrupt for the edge capture timer.  Note that we
	// use the capture match interrupt and NOT the timeout interrupt!
	IntEnable(INT_TIMER4A);
	TimerIntEnable(TIMER4_BASE, TIMER_CAPA_MATCH);

	// Timer Moudle(Timer A & Timer B) Clock Source Set
	TimerClockSourceSet(TIMER4_BASE, TIMER_CLOCK_SYSTEM);  // TIMER_CLOCK_PIOSC or  TIMER_CLOCK_SYSTEM

	// Enable the timer.
	TimerEnable(TIMER4_BASE, TIMER_A);

	// At this point, the timer will count up every time a negative  edge is detected on the relevant pin .
	while (1)
	{
		if (g_intFlag == 1) {
			UARTprintf("%d Positive edges detected\n", g_ui32IntCount);
			g_intFlag =0;
		}

	}
}