cs_ex3_XT1SourcesACLK.c

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 * Copyright (c) 2017, Texas Instruments Incorporated
 * All rights reserved.
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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
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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//******************************************************************************
//******************************************************************************
#include "driverlib.h"
 
//*****************************************************************************
//
//Variable to store status of Oscillator fault flags
//
//*****************************************************************************
uint16_t status;
 
void main (void)
{
    //Stop watchdog timer
    WDT_A_hold(WDT_A_BASE);
 
    //Set P1.0 to output direction
    GPIO_setAsOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN0
        );
 
    // Configure Pins for XIN and XOUT
    //Set P2.6 and P2.7 as Module Function Input.
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P2,
        GPIO_PIN6 + GPIO_PIN7,
        GPIO_SECONDARY_MODULE_FUNCTION
    );
 
    //Set P1.1 to output ACLK
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN1,
        GPIO_SECONDARY_MODULE_FUNCTION
        );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    //Initializes the XT1 crystal oscillator with no timeout
    //In case of failure, code hangs here.
    //For time-out instead of code hang use CS_turnOnXT1LFWithTimeout()
    CS_turnOnXT1LF(
        CS_XT1_DRIVE_0
        );
 
    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);
 
    //Enter LPM3 w/ interrupts
    __bis_SR_register(LPM3_bits + GIE);
 
    //For debugger
    __no_operation();
}
 
#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);
}