cs_ex1_DCO1MHzSWTrim.c

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 * Copyright (c) 2017, Texas Instruments Incorporated
 * All rights reserved.
 *
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 *
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 *    notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
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 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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//******************************************************************************
//******************************************************************************
#include "driverlib.h"
#include "Board.h"
 
//*****************************************************************************
//
//Target frequency for MCLK in kHz
//
//*****************************************************************************
#define CS_MCLK_DESIRED_FREQUENCY_IN_KHZ   1000
 
//*****************************************************************************
//
//MCLK/FLLRef Ratio
//
//*****************************************************************************
#define CS_MCLK_FLLREF_RATIO   30
 
//*****************************************************************************
//
//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 watchdog timer
    WDT_A_hold(WDT_A_BASE);
 
    //Set LED2 to output direction
    GPIO_setAsOutputPin(
        GPIO_PORT_LED2,
        GPIO_PIN_LED2
        );
 
    //ACLK set out to pins
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_ACLK,
        GPIO_PIN_ACLK,
        GPIO_FUNCTION_ACLK
        );
    //SMCLK set out to pins
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_SMCLK,
        GPIO_PIN_SMCLK,
        GPIO_FUNCTION_SMCLK
        );
    //MCLK set out to pins
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_MCLK,
        GPIO_PIN_MCLK,
        GPIO_FUNCTION_MCLK
        );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    //Set DCO FLL reference = REFO
    CS_initClockSignal(
        CS_FLLREF,
        CS_REFOCLK_SELECT,
        CS_CLOCK_DIVIDER_1
        );
 
    //Set ACLK = REFO
    CS_initClockSignal(
        CS_ACLK,
        CS_REFOCLK_SELECT,
        CS_CLOCK_DIVIDER_1
        );
    
    //Create struct variable to store proper software trim values
    CS_initFLLParam param = {0};
    
    //Set Ratio/Desired MCLK Frequency, initialize DCO, save trim values
    CS_initFLLCalculateTrim(
        CS_MCLK_DESIRED_FREQUENCY_IN_KHZ,
        CS_MCLK_FLLREF_RATIO,
        &param
        );
 
    //Clear all OSC fault flag
    CS_clearAllOscFlagsWithTimeout(1000);
 
    //For demonstration purpose, change DCO clock freq to 16MHz
    CS_initFLLSettle(
        16000,
        487
        );
 
    //Clear all OSC fault flag
    CS_clearAllOscFlagsWithTimeout(1000);
 
    //Reload DCO trim values that were calculated earlier
    CS_initFLLLoadTrim(
        CS_MCLK_DESIRED_FREQUENCY_IN_KHZ,
        CS_MCLK_FLLREF_RATIO,
        &param
        );
 
    //Clear all OSC fault flag
    CS_clearAllOscFlagsWithTimeout(1000);
 
    //Enable 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 = CS_getSMCLK();
    clockValue = CS_getMCLK();
    clockValue = CS_getACLK();
 
    while (1)
    {
        //Toggle LED2
        GPIO_toggleOutputOnPin(
            GPIO_PORT_LED2,
            GPIO_PIN_LED2
            );
 
        //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 = CS_clearAllOscFlagsWithTimeout(1000);
  } while(status != 0);
}