cs_ex4_XTSourcesDCOInternal.c

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/* --COPYRIGHT--,BSD
 * Copyright (c) 2017, Texas Instruments Incorporated
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * *  Redistributions of source code must retain the above copyright
 *    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.
 *
 * *  Neither the name of Texas Instruments Incorporated nor the names of
 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * --/COPYRIGHT--*/
//******************************************************************************
//*****************************************************************************
#include "driverlib.h"
 
//*****************************************************************************
//
//Desired Timeout for XT1 initialization
//
//*****************************************************************************
#define CS_XT1_TIMEOUT 50000
 
//*****************************************************************************
//
//Desired Timeout for XT2 initialization
//
//*****************************************************************************
#define CS_XT2_TIMEOUT 0
 
//*****************************************************************************
//
//XT1 Crystal Frequency being used
//
//*****************************************************************************
#define CS_XT1_CRYSTAL_FREQUENCY    32768
 
//*****************************************************************************
//
//Variable to store returned STATUS_SUCCESS or STATUS_FAIL
//
//*****************************************************************************
uint8_t returnValue = 0;
 
//*****************************************************************************
//
//Variable to store current clock values
//
//*****************************************************************************
uint32_t clockValue;
 
//*****************************************************************************
//
//Variable to store status of Oscillator fault flags
//
//*****************************************************************************
uint16_t status;
 
void main (void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Set P1.1 to output ACLK
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN1,
        GPIO_SECONDARY_MODULE_FUNCTION
        );
 
    //Set P1.0 to output SMCLK
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN0,
        GPIO_SECONDARY_MODULE_FUNCTION
        );
 
    //Port select XT1
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P2,
        GPIO_PIN6 + GPIO_PIN7,
        GPIO_SECONDARY_MODULE_FUNCTION
    );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    //Initializes the XT1 and XT2 crystal frequencies being used
    CS_setExternalClockSource(
        CS_XT1_CRYSTAL_FREQUENCY
        );
 
    //Initialize XT1. Returns STATUS_SUCCESS if initializes successfully
    returnValue = CS_turnOnXT1LFWithTimeout(
        CS_XT1_DRIVE_0,
        CS_XT1_TIMEOUT
        );
 
    //Select XT1 as ACLK source
    CS_initClockSignal(
        CS_ACLK,
        CS_XT1CLK_SELECT,
        CS_CLOCK_DIVIDER_1
        );
 
    //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_getMCLK();
    clockValue = CS_getACLK();
    clockValue = CS_getSMCLK();
 
    //Loop in place
    while (1) ;
}
 
#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);
}