Sample MSP432 SPI with DMA

/*
 * -------------------------------------------
 *    MSP432 DriverLib - v2_20_00_08
 * -------------------------------------------
 *
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/*******************************************************************************
 * MSP432 DMA - eUSCI SPI Transfer Using DMA
 *
 * Description: In this code example, the MSP432 's DMA controller is used in
 * conjunction with the eUSCI_A0 SPI configuration to demonstrate how to use
 * hardware triggered DMA transfers. One DMA transfer is setup, Channel 0 is
 * for the DMA transfer. Once the transfers are setup and initialized, the
 * device is put to sleep. While sleeping, the DMA controller will automatically
 * transfer the data from the const array and out through the uESCI A0 SPI
 * module as a master. When the DMA transfer is complete, an interrupt will be
 * fired and the master will disable further interrupts
 *
 * This program runs infinitely until manually halted by the user.
 *
 *                MSP432P401
 *             ------------------
 *         /|\|                  |
 *          | |                  |
 *          --|RST    P1.1 (CLK) |
 *            |       P1.3 (MOSI)|
 *            |                  |
 *
 * Author: Ryan Brown
 ******************************************************************************/
/* DriverLib Includes */
#include "driverlib.h"

/* Standard Includes */
#include <stdint.h>

#include <string.h>
#include <stdbool.h>

/* SPI Master Configuration Parameter */
const eUSCI_SPI_MasterConfig spiMasterConfig =
{
        EUSCI_A_SPI_CLOCKSOURCE_SMCLK,             // MCLK Clock Source
        12000000,                                  // MCLK = 12MHz
        400000,                                    // SPICLK = 400khz
        EUSCI_A_SPI_MSB_FIRST,                     // MSB First
        EUSCI_A_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT,    // Phase
        EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_LOW,    // Low polarity
        EUSCI_A_SPI_3PIN                           // 3Wire SPI Mode
};

/* DMA Control Table */
#ifdef ewarm
#pragma data_alignment=256
#else
#pragma DATA_ALIGN(controlTable, 256)
#endif
uint8_t controlTable[256];

/* Extern */
extern uint8_t data_array[];

int main(void)
{
    /* Halting Watchdog */
    WDT_A_holdTimer();

    CS_setDCOCenteredFrequency(CS_DCO_FREQUENCY_12);

    /* Port 2.4 as GPIO used for CS active low */
    GPIO_setAsOutputPin(GPIO_PORT_P2, GPIO_PIN4);
    GPIO_setOutputHighOnPin(GPIO_PORT_P2, GPIO_PIN4);

    /* Selecting P2.1 P2.2 and P2.3 in SPI mode */
    GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P2,
            GPIO_PIN1 | GPIO_PIN2 | GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);

    /* Configuring SPI in 3wire master mode */
    SPI_initMaster(EUSCI_A1_BASE, &spiMasterConfig);

    /* Enable SPI module */
    SPI_enableModule(EUSCI_A1_BASE);

    /* Configuring DMA module */
    DMA_enableModule();
    DMA_setControlBase(controlTable);

    DMA_disableChannel(2);
    /* Assigning Channel 2 to EUSCIA0TX0 */
    DMA_assignChannel(DMA_CH2_EUSCIA1TX);

     /* Disabling channel attributes */
    DMA_disableChannelAttribute(DMA_CH2_EUSCIA1TX,
                                UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
                                UDMA_ATTR_HIGH_PRIORITY |
                                UDMA_ATTR_REQMASK);

    /* Setting Control Indexes */
    DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH2_EUSCIA1TX,
            UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_1);
    DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH2_EUSCIA1TX,
            UDMA_MODE_BASIC, data_array,
            (void*) MAP_SPI_getTransmitBufferAddressForDMA(EUSCI_A1_BASE), 1024);

    /* Assigning/Enabling Interrupts */
    DMA_assignInterrupt(DMA_INT1, 2);
    Interrupt_enableInterrupt(INT_DMA_INT1);

    /* Drive CS Low to indicate start of the dtransfer */
    GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN4);

    /* Now that the DMA is primed and setup, enabling the channels. The EUSCI
     * hardware should take over and transfer/receive all bytes */
    DMA_enableChannel(2);

    /* Polling to see if the TX buffer is ready */
    while (!(SPI_getInterruptStatus(EUSCI_A1_BASE,EUSCI_A_SPI_TRANSMIT_INTERRUPT)));

    //PCM_gotoLPM0InterruptSafe();

    while(1);
}

/* Completion interrupt for eUSCIA0 TX */
void dma_1_interrupt(void)
{
    /* Disabling the completion interrupt and disabling the DMA channels */
    DMA_disableChannel(2);
    DMA_disableInterrupt(INT_DMA_INT1);
    /* Drive CS High to indicate end of the dtransfer */
    GPIO_setOutputHighOnPin(GPIO_PORT_P2, GPIO_PIN4);
}