dma_ex1_repeatedBlock.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.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
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 *    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"
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#include "driverlib.h"
 
//******************************************************************************
//******************************************************************************
 
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
        );
 
    //Initialize and Setup DMA Channel 0
    /*
     * Base Address of the DMA Module
     * Configure DMA channel 0
     * Configure channel for repeated block transfers
     * DMA interrupt flag will be set after every 16 transfers
     * Use DMA_startTransfer() function to trigger transfers
     * Transfer Word-to-Word
     * Trigger upon Rising Edge of Trigger Source Signal
     */
    DMA_initParam param = {0};
    param.channelSelect = DMA_CHANNEL_0;
    param.transferModeSelect = DMA_TRANSFER_REPEATED_BLOCK;
    param.transferSize = 16;
    param.triggerSourceSelect = DMA_TRIGGERSOURCE_0;
    param.transferUnitSelect = DMA_SIZE_SRCWORD_DSTWORD;
    param.triggerTypeSelect = DMA_TRIGGER_RISINGEDGE;
    DMA_init(&param);
    /*
     * Base Address of the DMA Module
     * Configure DMA channel 0
     * Use 0x1C00 as source
     * Increment source address after every transfer
     */
    DMA_setSrcAddress(
        DMA_CHANNEL_0,
        0x1C00,
        DMA_DIRECTION_INCREMENT);
    /*
     * Base Address of the DMA Module
     * Configure DMA channel 0
     * Use 0x1C20 as destination
     * Increment destination address after every transfer
     */
    DMA_setDstAddress(
        DMA_CHANNEL_0,
        0x1C20,
        DMA_DIRECTION_INCREMENT);
 
    //Enable transfers on DMA channel 0
    DMA_enableTransfers(
        DMA_CHANNEL_0);
 
    while (1)
    {
        //set P1.0
        GPIO_setOutputHighOnPin(
            GPIO_PORT_P1,
            GPIO_PIN0
            );
 
        //Start block tranfer on DMA channel 0
        DMA_startTransfer(
            DMA_CHANNEL_0);
 
        //Clear P1.0 LED off
        GPIO_setOutputLowOnPin(
            GPIO_PORT_P1,
            GPIO_PIN0
            );
    }
}