ref_a_ex1_ctlADC12B.c

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//******************************************************************************
//
//   REFA - ADC12B, Using REFA Module to control Internal Reference
//
//   This example shows how to configure the internal reference of REFA module
//   using the REFACTL0 control register. The ADC12B uses the internal 2.5V
//   reference and performs a single conversion on channel A0. The conversion
//   results are stored in ADC12BMEM0. Test by applying a voltage to channel A0,
//   then setting and running to a break point at the "__no_operation()"
//   instruction. To view the conversion results, open an ADC12B register window
//   in debugger and view the contents of ADC12BMEM0.
//
//   NOTE: REFAMSTR bit in REFACTL0 regsiter is by default set to 1. This allows
//   the REFACTL0 control regsiters to configure the reference setting. The
//   legacy ADC12B reference control bits ADC12REFAON, ADC12REFA2_5, ADC12BTCOFF
//   and ADC12BREFAOUT are dont care in this case.
//
//                 MSP430FR5969
//              -----------------
//          /|\|                 |
//           | |                 |
//           --|RST              |
//             |                 |
//             |          P1.0/A0|<- Vin
//             |                 |
//
//
//   This example uses the following peripherals and I/O signals.  You must
//   review these and change as needed for your own board:
//   - REFA peripheral
//   - ADC12B peripheral
//   - GPIO Port peripheral
//   - A0
//
//   This example uses the following interrupt handlers.  To use this example
//   in your own application you must add these interrupt handlers to your
//   vector table.
//   - None.
//
//******************************************************************************
#include "driverlib.h"
 
void main (void)
{
    //Stop watchdog timer
    WDT_A_hold(WDT_A_BASE);
 
    //Set P1.0 as Ternary Module Function Output.
    /*
 
    * Select Port 1
    * Set Pin 0 to output Ternary Module Function, (A0, C0, VREFA-, VeREFA-).
    */
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN0,
        GPIO_TERNARY_MODULE_FUNCTION
    );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    //If ref generator busy, WAIT
    while (Ref_A_isRefGenBusy(REF_A_BASE)) ;
    //Select internal ref = 2.5V
    Ref_A_setReferenceVoltage(REF_A_BASE,
        REF_A_VREF2_5V);
    //Internal Reference ON
    Ref_A_enableReferenceVoltage(REF_A_BASE);
 
    //Delay (~75us) for Ref to settle
    __delay_cycles(75);
 
    //Initialize the ADC12 Module
    /*
    * Base address of ADC12 Module
    * Use internal ADC12 bit as sample/hold signal to start conversion
    * USE MODOSC 5MHZ Digital Oscillator as clock source
    * Use default clock divider/pre-divider of 1
     * Map to internal channel 0
    */
    ADC12_B_initParam initParam = {0};
    initParam.sampleHoldSignalSourceSelect = ADC12_B_SAMPLEHOLDSOURCE_SC;
    initParam.clockSourceSelect = ADC12_B_CLOCKSOURCE_ADC12OSC;
    initParam.clockSourceDivider = ADC12_B_CLOCKDIVIDER_1;
    initParam.clockSourcePredivider = ADC12_B_CLOCKPREDIVIDER__1;
    initParam.internalChannelMap = ADC12_B_MAPINTCH0;
    ADC12_B_init(ADC12_B_BASE, &initParam);
 
    //Enable the ADC12B module
    ADC12_B_enable(ADC12_B_BASE);
 
    /*
     * Base address of ADC12B Module
     * For memory buffers 0-7 sample/hold for 64 clock cycles
     * For memory buffers 8-15 sample/hold for 4 clock cycles (default)
     * Disable Multiple Sampling
     */
    ADC12_B_setupSamplingTimer(ADC12_B_BASE,
        ADC12_B_CYCLEHOLD_64_CYCLES,
        ADC12_B_CYCLEHOLD_4_CYCLES,
        ADC12_B_MULTIPLESAMPLESDISABLE);
 
    //Configure Memory Buffer
    /*
     * Base address of the ADC12B Module
     * Configure memory buffer 0
     * Map input A0 to memory buffer 0
     * Vref+ = Vref+ (INT)
     * Vref- = AVss
     */
    ADC12_B_configureMemoryParam configureMemoryParam = {0};
    configureMemoryParam.memoryBufferControlIndex = ADC12_B_MEMORY_0;
    configureMemoryParam.inputSourceSelect = ADC12_B_INPUT_A0;
    configureMemoryParam.refVoltageSourceSelect = ADC12_B_VREFPOS_INTBUF_VREFNEG_VSS;
    configureMemoryParam.endOfSequence = ADC12_B_NOTENDOFSEQUENCE;
    configureMemoryParam.windowComparatorSelect = ADC12_B_WINDOW_COMPARATOR_DISABLE;
    configureMemoryParam.differentialModeSelect = ADC12_B_DIFFERENTIAL_MODE_DISABLE;
    ADC12_B_configureMemory(ADC12_B_BASE, &configureMemoryParam);
 
    while (1)
    {
        //Enable/Start sampling and conversion
        /*
         * Base address of ADC12B Module
         * Start the conversion into memory buffer 0
         * Use the single-channel, single-conversion mode
         */
        ADC12_B_startConversion(ADC12_B_BASE,
            ADC12_B_MEMORY_0,
            ADC12_B_SINGLECHANNEL);
 
        //Poll for interrupt on memory buffer 0
        while (!ADC12_B_getInterruptStatus(ADC12_B_BASE,
                   0,
                   ADC12IFG0));
 
        //SET BREAKPOINT HERE
        __no_operation();
    }
}