TM4C1294NCPDT: Not able to generate 1ms delay using timers.

Thanks you for your quick response sir,

I configured same as you suggested sir but i'am still not able to generate the 1ms time delay. I loaded the period value 23000 to generate the 50ms delay but when period value is less than 40000 is loaded in to the timerloadset() it's not entering in to the timer isr. can you please tell me the sir, how to set the prescale value to generate the 1ms and 1ns time delay.

int main(void)
{

ui32SysClock=SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),120000000);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);

GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE , GPIO_PIN_0 | GPIO_PIN_1);

 TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_PERIODIC);

TimerPrescaleSet(TIMER0_BASE,TIMER_A,255);

//period=65535;          // for 140 ms

period = 23000;

TimerLoadSet(TIMER0_BASE , TIMER_A , period-1);

IntEnable(INT_TIMER0A);
TimerIntEnable(TIMER0_BASE , TIMER_TIMA_TIMEOUT);
IntMasterEnable();

TimerEnable(TIMER0_BASE , TIMER_A);

while(1);

return 0;
}

void Timer0IntHandler(void)
{
TimerIntClear(TIMER0_BASE , TIMER_TIMA_TIMEOUT);

if(GPIOPinRead(GPIO_PORTN_BASE , GPIO_PIN_1))
{
GPIOPinWrite(GPIO_PORTN_BASE , GPIO_PIN_1 , 0);
}
else
{
GPIOPinWrite(GPIO_PORTN_BASE , GPIO_PIN_1, 2);
}
}

Thanks ,

Venkatadri

I don't know what the problem was. I took your code and changed the prescale to 120 and the timer preload value to 1000 and have a 1mS periodic interrupt.

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "inc/hw_ints.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
#include "driverlib/interrupt.h"

uint32_t ui32SysClock;

int main(void)
{
    unsigned int period;

    ui32SysClock=SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),120000000);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);

    GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE , GPIO_PIN_0 | GPIO_PIN_1);

    TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_PERIODIC);

    // 120MHz divided by 120 gives 1MHz timer clock
    TimerPrescaleSet(TIMER0_BASE, TIMER_A, 120 - 1);

    //period of 1000 gives 1 mS interrupt
    period = 1000;

    TimerLoadSet(TIMER0_BASE , TIMER_A , period-1);

    IntEnable(INT_TIMER0A);
    TimerIntEnable(TIMER0_BASE , TIMER_TIMA_TIMEOUT);
    IntMasterEnable();

    TimerEnable(TIMER0_BASE , TIMER_A);

    while(1);

    return 0;
}

void Timer0IntHandler(void)
{
    TimerIntClear(TIMER0_BASE , TIMER_TIMA_TIMEOUT);

    if(GPIOPinRead(GPIO_PORTN_BASE , GPIO_PIN_1))
    {
        GPIOPinWrite(GPIO_PORTN_BASE , GPIO_PIN_1 , 0);
    }
    else
    {
        GPIOPinWrite(GPIO_PORTN_BASE , GPIO_PIN_1, 2);
    }
}