[LaunchXL-F280049C] cpuTimer0

Ti가 매우 친절한 이유는 개발 환경에 대한 대부분을 오픈 시켜서 빠르게 스터디가 가능해요.

그 중 당연 으뜸은 예제프로그램이죠.. ^^;;;

 

해당 코드는 예제프로그램을 보고 진행하였습니다.

#include "driverlib.h"
#include "device.h"


uint16_t cpuTimer0IntCount;


__interrupt void cpuTimer0ISR(void);
void initCPUTimers(void);
void configCPUTimer(uint32_t, float, float);

void main(void)
{
    Device_init();
    Device_initGPIO();

    Interrupt_initModule();
    Interrupt_initVectorTable();


    Interrupt_register(INT_TIMER0, &cpuTimer0ISR);      // ISR

    initCPUTimers();
    configCPUTimer(CPUTIMER0_BASE, DEVICE_SYSCLK_FREQ, 100000);    // Interrupt every 100 ms
    CPUTimer_enableInterrupt(CPUTIMER0_BASE);
    Interrupt_enable(INT_TIMER0);
    CPUTimer_startTimer(CPUTIMER0_BASE);

    EINT;       // Enable Global Interrupt
    ERTM;       // Enable Realtime Interrupt
    while(1)
    {

    }
}

void initCPUTimers(void)
{
    //
    // Initialize timer period to maximum
    //
    CPUTimer_setPeriod(CPUTIMER0_BASE, 0xFFFFFFFF);

    //
    // Initialize pre-scale counter to divide by 1 (SYSCLKOUT)
    //
    CPUTimer_setPreScaler(CPUTIMER0_BASE, 0);

    //
    // Make sure timer is stopped
    //
    CPUTimer_stopTimer(CPUTIMER0_BASE);

    //
    // Reload all counter register with period value
    //
    CPUTimer_reloadTimerCounter(CPUTIMER0_BASE);

    //
    // Reset interrupt counter
    //
    cpuTimer0IntCount = 0;
}

//
// configCPUTimer - This function initializes the selected timer to the
// period specified by the "freq" and "period" parameters. The "freq" is
// entered as Hz and the period in uSeconds. The timer is held in the stopped
// state after configuration.
//
void configCPUTimer(uint32_t cpuTimer, float freq, float period)
{
    uint32_t temp;

    //
    // Initialize timer period:
    //
    temp = (uint32_t)((freq / 1000000) * period);
    CPUTimer_setPeriod(cpuTimer, temp);

    //
    // Set pre-scale counter to divide by 1 (SYSCLKOUT):
    //
    CPUTimer_setPreScaler(cpuTimer, 0);

    //
    // Initializes timer control register. The timer is stopped, reloaded,
    // free run disabled, and interrupt enabled.
    // Additionally, the free and soft bits are set
    //
    CPUTimer_stopTimer(cpuTimer);
    CPUTimer_reloadTimerCounter(cpuTimer);
    CPUTimer_setEmulationMode(cpuTimer, CPUTIMER_EMULATIONMODE_STOPAFTERNEXTDECREMENT);
    CPUTimer_enableInterrupt(cpuTimer);

    //
    // Resets interrupt counters for the three cpuTimers
    //
    if (cpuTimer == CPUTIMER0_BASE)
    {
        cpuTimer0IntCount = 0;
    }
}

__interrupt void cpuTimer0ISR(void)
{
    cpuTimer0IntCount++;

    GPIO_togglePin(23U);

    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP1);
}

 

Device SYSCLK Frequency는 20MHz이고 100ms LED ON/OFF 예제입니다.