ucs_ex1_DCO12MHz.c

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//******************************************************************************
//******************************************************************************
#include "driverlib.h"
//*****************************************************************************
//
//Target frequency for MCLK in kHz
//
//*****************************************************************************
#define UCS_MCLK_DESIRED_FREQUENCY_IN_KHZ   12000
 
//*****************************************************************************
//
//MCLK/FLLRef Ratio
//
//*****************************************************************************
#define UCS_MCLK_FLLREF_RATIO   366
 
//*****************************************************************************
//
//Variable to store current Clock values
//
//*****************************************************************************
uint32_t clockValue = 0;
 
//*****************************************************************************
//
//Variable to store status of Oscillator fault flags
//
//*****************************************************************************
uint16_t status;
 
void main (void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Set VCore = 1 for 12MHz clock
    PMM_setVCore(PMM_CORE_LEVEL_1);
 
    //Set P1.0 to output direction
    GPIO_setAsOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN0
        );
 
    //ACLK, MCLK, MCLK set out to pins
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P11,
        GPIO_PIN0 + GPIO_PIN1 + GPIO_PIN2
        );
 
    //Set DCO FLL reference = REFO
    UCS_initClockSignal(
        UCS_FLLREF,
        UCS_REFOCLK_SELECT,
        UCS_CLOCK_DIVIDER_1
        );
    //Set ACLK = REFO
    UCS_initClockSignal(
        UCS_ACLK,
        UCS_REFOCLK_SELECT,
        UCS_CLOCK_DIVIDER_1
        );
 
    //Set Ratio and Desired MCLK Frequency  and initialize DCO
    UCS_initFLLSettle(
        UCS_MCLK_DESIRED_FREQUENCY_IN_KHZ,
        UCS_MCLK_FLLREF_RATIO
        );
 
    // Enable global oscillator fault flag
    SFR_clearInterrupt(SFR_OSCILLATOR_FAULT_INTERRUPT);
    SFR_enableInterrupt(SFR_OSCILLATOR_FAULT_INTERRUPT);
 
    // Enable global interrupt
    __bis_SR_register(GIE);
 
    //Verify if the Clock settings are as expected
    clockValue = UCS_getSMCLK();
    clockValue = UCS_getMCLK();
    clockValue = UCS_getACLK();
 
    while (1)
    {
        //Toggle P1.0
        GPIO_toggleOutputOnPin(
            GPIO_PORT_P1,
            GPIO_PIN0
            );
 
        //Delay
        __delay_cycles(1000000);
    }
}
 
 
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=UNMI_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(UNMI_VECTOR)))
#endif
void NMI_ISR(void)
{
  do {
    // If it still can't clear the oscillator fault flags after the timeout,
    // trap and wait here.
    status = UCS_clearAllOscFlagsWithTimeout(1000);
  } while(status != 0);
}