ucs_ex4_XTSourcesDCOInternal.c

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/* --COPYRIGHT--,BSD
 * Copyright (c) 2017, Texas Instruments Incorporated
 * All rights reserved.
 *
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 *    notice, this list of conditions and the following disclaimer.
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 * *  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"
//*****************************************************************************
//
//Desired Timeout for XT1 initialization
//
//*****************************************************************************
#define UCS_XT1_TIMEOUT 50000
 
//*****************************************************************************
//
//Desired Timeout for XT2 initialization
//
//*****************************************************************************
#define UCS_XT2_TIMEOUT 50000
 
//*****************************************************************************
//
//XT1 Crystal Frequency being used
//
//*****************************************************************************
#define UCS_XT1_CRYSTAL_FREQUENCY    32768
 
//*****************************************************************************
//
//XT2 Crystal Frequency being used
//
//*****************************************************************************
#define UCS_XT2_CRYSTAL_FREQUENCY   24000000
 
//*****************************************************************************
//
//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);
 
    //ACLK, MCLK, SMCLk set out to pins
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P11,
        GPIO_PIN0 + GPIO_PIN1 + GPIO_PIN2
        );
 
    //Port select XT1
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P7,
        GPIO_PIN0 + GPIO_PIN1
        );
 
    //Initializes the XT1 and XT2 crystal frequencies being used
    UCS_setExternalClockSource(
        UCS_XT1_CRYSTAL_FREQUENCY,
        UCS_XT2_CRYSTAL_FREQUENCY
        );
 
    //Initialize XT1. Returns STATUS_SUCCESS if initializes successfully
    returnValue = UCS_turnOnLFXT1WithTimeout(
        UCS_XT1_DRIVE_0,
        UCS_XCAP_3,
        UCS_XT1_TIMEOUT
        );
 
    //Startup HF XT2 crystal Port select XT2
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P5,
        GPIO_PIN2 + GPIO_PIN3
        );
 
    //Initialize XT2. Returns STATUS_SUCCESS if initializes successfully
    returnValue = UCS_turnOnXT2WithTimeout(
        UCS_XT2_DRIVE_4MHZ_8MHZ,
        UCS_XT2_TIMEOUT
        );
 
    //Select XT1 as ACLK source
    UCS_initClockSignal(
        UCS_ACLK,
        UCS_XT1CLK_SELECT,
        UCS_CLOCK_DIVIDER_1
        );
 
    //Select XT2 as SMCLK source
    UCS_initClockSignal(
        UCS_SMCLK,
        UCS_XT2CLK_SELECT,
        UCS_CLOCK_DIVIDER_1
        );
 
    // 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_getMCLK();
    clockValue = UCS_getACLK();
    clockValue = UCS_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 = UCS_clearAllOscFlagsWithTimeout(1000);
  } while(status != 0);
}