5509A读取SD卡使能DMA

可以参考C:\ti\C55xxCSL\examples\generic5509\csl\dma\dma4，这个例程是McBSP+DMA的。

需要做修改的地方：

1. DMA event改成MMC receive event， MMC transmit event

Table 3−4. Synchronization Control Function
http://www.ti.com/lit/ds/symlink/tms320vc5509a.pdf

2. MMCCTL.DMAEN位使能 

这个在EBSR寄存器里设置。
3.5.1 External Bus Selection Register (EBSR)
http://www.ti.com/lit/ds/symlink/tms320vc5509a.pdf 

非常感谢您的回答，我想问下，CSL例程读取SD卡程序时应该已经设置了吧？如果没有设置的话他如何读取SD卡的数据呢？

请问下如果没有设置的话我要调用哪个函数来对EBSR进行设置？

如果你之前的SD卡程序已经可以读写了，那应该已经是设好了的，你也可以看一下EBSR的值确认。

可以用CHIP_FSET函数设置，也可以直接写代码，如下：
#define EBSR            (*(volatile ioport unsigned short*)0x6c00)

....
EBSR =; 

好的，那应该是已经设置好了的，我SD读写的程序是直接拿CSL的例程的

还有我想问下，retVal = MMC_read(mmc0,0x219a00,datareceive,512);这句话，我如何将其应用到DMA的使用中？我想做的是将SD的一段数据取出来放到DARAM中

下面是我的程序

/*
 * Copyright (C) 2003 Texas Instruments Incorporated
 * All Rights Reserved
 */
/*
 *---------main_dma4.c---------
 * This example places the MCBSP in digital loopback mode and
 * syncs MCBSP receive with DMA channel 4 and MCBSP transmit
 * with DMA channel 5.
 * The example uses predefined CSL macros and symbolic
 * constants to create the initialization values needed for
 * the MCBSP and DMA control registers to effect the transfer
 */
#include <stdio.h>

#include <csl_mmc.h>
#include <csl_mcbsp.h>
#include <csl_dma.h>
#include <csl_irq.h>

#define EBSR            (*(volatile ioport unsigned short*)0x6c00)

#pragma DATA_SECTION(mmc0,"cslmem")
MMC_Handle mmc0;
MMC_CardObj *card, cardalloc;
MMC_CardIdObj *cid, cardid;

int count, retVal;
Uint16 rca;
Uint16 cardtype;

/* Because of different operating clock frequencies, the Init structure for c5509    *
 * and c5509a have different values for memory and function clock divide down values */
#if CHIP_5509A
  MMC_SetupNative Init = {
    0,   /* Disable DMA for data read/write                 */
    0,   /* Set level of edge detection for DAT3 pin        */
    0,   /* Determines if MMC goes IDLE during IDLE instr   */
    1,   /* Memory clk reflected on CLK Pin                 */
    7,   /* CPU CLK to MMC function clk divide down         */
    5,   /* MMC function clk to memory clk divide down      */
    0,   /* No. memory clks to wait before response timeout */
    0,   /* No. memory clks to wait before data timeout     */
    512, /* Block Length must be same as CSD                */
  };
#else
  MMC_SetupNative Init = {
    0,   /* Disable DMA for data read/write                 */
    0,   /* Set level of edge detection for DAT3 pin        */
    0,   /* Determines if MMC goes IDLE during IDLE instr   */
    1,   /* Memory clk reflected on CLK Pin                 */
    3,   /* CPU CLK to MMC function clk divide down         */
    3,   /* MMC function clk to memory clk divide down      */
    0,   /* No. memory clks to wait before response timeout */
    0,   /* No. memory clks to wait before data timeout     */
    512, /* Block Length must be same as CSD                */
  };
#endif

/* Read and write buffers */
Uint16 datasend[512];
Uint16 datareceive[512];

//---------Global constants---------
#define N       128

//---------Global data definition---------

/* Define transmit and receive buffers */
#pragma DATA_SECTION(xmt,"dmaMem")
Uint16 xmt[N];
#pragma DATA_SECTION(rcv,"dmaMem")
Uint16 rcv[N];

  MCBSP_Config ConfigLoopBack16= {
  MCBSP_SPCR1_RMK(
    MCBSP_SPCR1_DLB_ON,                    /* DLB    = 1 数字回环模式使能*/
    MCBSP_SPCR1_RJUST_RZF,                 /* RJUST  = 0 接收数据符号扩展和调节方式(左对齐数据和右对齐数据等等)*/
    MCBSP_SPCR1_CLKSTP_DISABLE,            /* CLKSTP = 0 Clock stop mode disable */
    MCBSP_SPCR1_DXENA_NA,                  /* DXENA  = 0 DX引脚延时使能*/
    MCBSP_SPCR1_ABIS_DISABLE,              /* ABIS   = 0 reserved always write 0*/
    MCBSP_SPCR1_RINTM_RRDY,                /* RINTM  = 0 接收中断模式（可能需要设置？）*/
    0,                                     /* RSYNCER = 0 接收帧同步错误标志*/
    MCBSP_SPCR1_RRST_DISABLE               /* RRST   = 0 禁止接收器复位*/
   ),
    MCBSP_SPCR2_RMK(
    MCBSP_SPCR2_FREE_NO,                   /* FREE   = 0 free run bit, The McBSP transmit and receive clocks are affected as determined by the SOFT bit*/
    MCBSP_SPCR2_SOFT_NO,                   /* SOFT   = 0 Soft stop bit, Hard stop*/
    MCBSP_SPCR2_FRST_FSG,                  /* FRST   = 0 帧同步逻辑复位*/
    MCBSP_SPCR2_GRST_CLKG,                 /* GRST   = 0 采样率发生器复位*/
    MCBSP_SPCR2_XINTM_XRDY,                /* XINTM  = 0 发送中断模式（可能需要设置？）*/
    0,                                     /* XSYNCER = N/A transmit frame-sync error bit, no error*/
    MCBSP_SPCR2_XRST_DISABLE               /* XRST   = 0 发送器复位*/
    //注意：开始一定要设置为disable，否则不能设置它的寄存器，全部为默认值，导致不能正常接收，

    //在程序调用C库函数mcbspstart时会在设为1，McBSP便退出reset状态开始工作

   ),
  MCBSP_RCR1_RMK(
  MCBSP_RCR1_RFRLEN1_OF(0),                /* RFRLEN1 = 0 接收阶段1的帧长（1-128）个字*/
  MCBSP_RCR1_RWDLEN1_16BIT                 /* RWDLEN1 = 5 接收阶段1的字长*/
  ),
 MCBSP_RCR2_RMK(
    MCBSP_RCR2_RPHASE_SINGLE,              /* RPHASE  = 0 接收帧的阶段数*/
    MCBSP_RCR2_RFRLEN2_OF(0),              /* RFRLEN2 = 0 接收阶段2关闭*/
    MCBSP_RCR2_RWDLEN2_8BIT,               /* RWDLEN2 = 0 接收阶段2的字长为8位*/
    MCBSP_RCR2_RCOMPAND_MSB,               /* RCOMPAND = 0 接收数据压扩模式*/
    MCBSP_RCR2_RFIG_YES,                   /* RFIG    = 0 忽略不期望接收的帧同步信号*/
    MCBSP_RCR2_RDATDLY_0BIT                /* RDATDLY = 0 接收数据不延时*/
    ),
   MCBSP_XCR1_RMK(
    MCBSP_XCR1_XFRLEN1_OF(0),              /* XFRLEN1 = 0 发送阶段1的帧长（1-128）个字*/
    MCBSP_XCR1_XWDLEN1_16BIT               /* XWDLEN1 = 5 发送阶段1的字长*/

 ),
 MCBSP_XCR2_RMK(
    MCBSP_XCR2_XPHASE_SINGLE,              /* XPHASE  = 0 Transmit phase number bit, single-phase frame*/
    MCBSP_XCR2_XFRLEN2_OF(0),              /* XFRLEN2 = 0 */
    MCBSP_XCR2_XWDLEN2_8BIT,               /* XWDLEN2 = 0 */
    MCBSP_XCR2_XCOMPAND_MSB,               /* XCOMPAND = 0 Transmit companding mode bits, 0, no companding,MSB received first*/
    MCBSP_XCR2_XFIG_YES,                   /* XFIG    = 0 Transmit frame-sync ignore bit, 1, frame-sync detect*/
    MCBSP_XCR2_XDATDLY_0BIT                /* XDATDLY = 0 Transmit data delay bits*/
  ),
 MCBSP_SRGR1_RMK(
   MCBSP_SRGR1_FWID_OF(1),                /* FWID    = 1 帧同步信号FSG的脉冲宽度*/
   MCBSP_SRGR1_CLKGDV_OF(1)               /* CLKGDV  = 1 输出时钟信号CLKG的分频值*/
 ),
 MCBSP_SRGR2_RMK(
    MCBSP_SRGR2_GSYNC_FREE,                /* FREE    = 0 */
    MCBSP_SRGR2_CLKSP_RISING,              /* CLKSP   = 0 */
    MCBSP_SRGR2_CLKSM_INTERNAL,            /* CLKSM   = 1 */
    MCBSP_SRGR2_FSGM_DXR2XSR,              /* FSGM    = 0 */
    MCBSP_SRGR2_FPER_OF(15)                /* FPER    = 0 */
 ),
 MCBSP_MCR1_DEFAULT,						//MCR是通道控制器
 MCBSP_MCR2_DEFAULT,
 MCBSP_PCR_RMK(
   MCBSP_PCR_IDLEEN_RESET,                 /* IDLEEN   = 0   The McBSP remains active when the PERIPH domain is idled */
   MCBSP_PCR_XIOEN_SP,                     /* XIOEN    = 0   Transmit I/O enable bit, CLKX,FSX,DX,CLKS pins are serial port pins*/
   MCBSP_PCR_RIOEN_SP,                     /* RIOEN    = 0   Receive I/O enable bit, CLKR,FSR,DR,CLKS pins are serial port pins*/
   MCBSP_PCR_FSXM_INTERNAL,                /* FSXM     = 1   发送帧同步模式：1为由MCBSP提供*/
   MCBSP_PCR_FSRM_EXTERNAL,                /* FSRM     = 0   接收帧同步模式：0为FSR引脚提供*/
   MCBSP_PCR_CLKXM_OUTPUT,                 /* CLKXM    = 1   Transmit clock mode bit*/
   MCBSP_PCR_CLKRM_INPUT,                  /* CLKRM    = 0   Receive clock mode bit*/
   MCBSP_PCR_SCLKME_NO,                    /* SCLKME   = 0   Sample rate generator input clock mode bit,used with CLKSM to select the input clock*/
   0,                                      /* DXSTAT = N/A   */
   MCBSP_PCR_FSXP_ACTIVEHIGH,              /* FSXP     = 0   Transmit frame-sync polarity bit, 0,transmit frame-sync pulses are active high*/
   MCBSP_PCR_FSRP_ACTIVEHIGH,              /* FSRP     = 0   Receive frame-sync polarity bit, 0,receive frame-sync pulses are active high*/
   MCBSP_PCR_CLKXP_RISING,                 /* CLKXP    = 0   Transmit clock polarity bit,1,transmit data is driven on the rising edge of CLKX*/
   MCBSP_PCR_CLKRP_FALLING                 /* CLKRP    = 0   Receive clock polarity bit*/
 ),
 MCBSP_RCERA_DEFAULT,						//通道使能寄存器
 MCBSP_RCERB_DEFAULT,
 MCBSP_RCERC_DEFAULT,
 MCBSP_RCERD_DEFAULT,
 MCBSP_RCERE_DEFAULT,
 MCBSP_RCERF_DEFAULT,
 MCBSP_RCERG_DEFAULT,
 MCBSP_RCERH_DEFAULT,
 MCBSP_XCERA_DEFAULT,
 MCBSP_XCERB_DEFAULT,
 MCBSP_XCERC_DEFAULT,
 MCBSP_XCERD_DEFAULT,
 MCBSP_XCERE_DEFAULT,
 MCBSP_XCERF_DEFAULT,
 MCBSP_XCERG_DEFAULT,
 MCBSP_XCERH_DEFAULT
};

/* Create DMA Receive Side Configuration */
DMA_Config  dmaRcvConfig = {
  DMA_DMACSDP_RMK(
    DMA_DMACSDP_DSTBEN_NOBURST,				//Destination burst :-不使用突发
    DMA_DMACSDP_DSTPACK_OFF,				//Destination packing :-目标口禁止打包
    DMA_DMACSDP_DST_DARAM,					//Destination selection :-接收的目标口是DARAM
	//00 SARAM;01 DARAM;10 EMIF;11 PERIPH
    DMA_DMACSDP_SRCBEN_NOBURST,				//Source burst :-源突发禁止
    DMA_DMACSDP_SRCPACK_OFF,				//Source packing :-源口禁止打包
    DMA_DMACSDP_SRC_PERIPH,					//Source selection :-外设mcbsp
    DMA_DMACSDP_DATATYPE_16BIT				 //Data type :-设置数据类型16bit字长
  ),                                       /* DMACSDP  */
  DMA_DMACCR_RMK(
    DMA_DMACCR_DSTAMODE_POSTINC,			//Destination address mode :-自动执行后增量（由于本程序中数据类型是16bit，所以+2）
    DMA_DMACCR_SRCAMODE_CONST,				//Source address mode :-源地址为恒定地址
    DMA_DMACCR_ENDPROG_ON,					//End of programmation bit :-
    DMA_DMACCR_REPEAT_OFF,					//Repeat condition :（AUTOINIT=1）才有效？-0 管编程配置结束位 1 不管编程配置结束位，结束传输自动初始化开始
											//0:Repeat only if ENDPROG = 1（AUTOINIT=1）
    DMA_DMACCR_AUTOINIT_OFF,				//Auto initialization bit :-
    DMA_DMACCR_EN_STOP,						//Channel enable :-设置时先关闭通道
    DMA_DMACCR_PRIO_LOW,					//Channel priority :-设置为低优先级
    DMA_DMACCR_FS_DISABLE,					//(FS_ELEMENT 单元事件同步)
    DMA_DMACCR_SYNC_REVT1					//Synchronization control bits
  ),                                       /* DMACCR   */
  DMA_DMACICR_RMK(
    DMA_DMACICR_BLOCKIE_OFF,				//Whole block interrupt enable :-块传输完成后中断不使能
    DMA_DMACICR_LASTIE_OFF,					//Last frame interrupt enable :-
    DMA_DMACICR_FRAMEIE_ON,					//Whole frame interrupt enable :-帧传输完成后中断使能
    DMA_DMACICR_FIRSTHALFIE_OFF,			//Half frame interrupt enable :-
    DMA_DMACICR_DROPIE_OFF,					//Sync. event drop interrupt enable :-
    DMA_DMACICR_TIMEOUTIE_OFF				//Time out interrupt enable :-
  ),                                       /* DMACICR  */
    (DMA_AdrPtr)(MCBSP_ADDR(DRR11)),        /* DMACSSAL 源地址低位*/
    0,                                     /* DMACSSAU 源地址高位*/
    (DMA_AdrPtr)&rcv,                      /* DMACDSAL 目的地址低位*/
    0,                                     /* DMACDSAU 目的地址高位*/
    N,                                     /* DMACEN   1帧内数据长度 N个数据一个帧*/
    1,                                     /* DMACFN   帧数大小*/
    0,                                     /* DMACFI  */
    0                                      /* DMACEI  */
  };

/* Create DMA Transmit Side Configuration */
DMA_Config  dmaXmtConfig = {
  DMA_DMACSDP_RMK(
    DMA_DMACSDP_DSTBEN_NOBURST,
    DMA_DMACSDP_DSTPACK_OFF,
    DMA_DMACSDP_DST_PERIPH,					//Destination selection :-外设mcbsp
    DMA_DMACSDP_SRCBEN_NOBURST,
    DMA_DMACSDP_SRCPACK_OFF,
    DMA_DMACSDP_SRC_DARAM,					//Source selection :DARAM
    DMA_DMACSDP_DATATYPE_16BIT
  ),                                       /* DMACSDP  */
  DMA_DMACCR_RMK(
    DMA_DMACCR_DSTAMODE_CONST,				//Destination address mode :-恒定地址
    DMA_DMACCR_SRCAMODE_POSTINC,			//Source address mode :-自动执行后增量（由于本程序中数据类型是16bit，所以+2
    DMA_DMACCR_ENDPROG_ON,
    DMA_DMACCR_REPEAT_OFF,
    DMA_DMACCR_AUTOINIT_OFF,
    DMA_DMACCR_EN_STOP,
    DMA_DMACCR_PRIO_LOW,
    DMA_DMACCR_FS_DISABLE,
    DMA_DMACCR_SYNC_XEVT1					//Synchronization control bits
  ),                                       /* DMACCR   */
  DMA_DMACICR_RMK(
    DMA_DMACICR_BLOCKIE_OFF,
    DMA_DMACICR_LASTIE_OFF,
    DMA_DMACICR_FRAMEIE_ON,
    DMA_DMACICR_FIRSTHALFIE_OFF,
    DMA_DMACICR_DROPIE_OFF,
    DMA_DMACICR_TIMEOUTIE_OFF
  ),                                       /* DMACICR  */
    (DMA_AdrPtr)&xmt[1],                   /* DMACSSAL */
    0,                                     /* DMACSSAU */
    (DMA_AdrPtr)(MCBSP_ADDR(DXR11)),       /* DMACDSAL */
    0,                                     /* DMACDSAU */
    N,                                     /* DMACEN   */
    1,                                     /* DMACFN   */
    0,                                     /* DMACFI   */
    0                                      /* DMACEI   */
};

/* Define a DMA_Handle object to be used with DMA_open function */
DMA_Handle hDmaRcv, hDmaXmt;

/* Define a MCBSP_Handle object to be used with MCBSP_open function */
MCBSP_Handle hMcbsp;

volatile Uint16 transferComplete = FALSE;
Uint16 err = 0;
Uint16 old_intm;
Uint16 xmtEventId, rcvEventId;

//---------Function prototypes---------
/* Reference start of interrupt vector table   */
/* This symbol is defined in file, vectors.s55 */
extern void VECSTART(void);

/* Protoype for interrupt functions */
interrupt void dmaXmtIsr(void);
interrupt void dmaRcvIsr(void);
void taskFxn(void);

//---------main routine---------
void main(void)
{
    Uint16 i;

    /* Initialize CSL library - This is REQUIRED !!! */
    CSL_init();

    /* Set IVPD/IVPH to start of interrupt vector table */
    IRQ_setVecs((Uint32)(&VECSTART));

    for (i = 0; i <= N - 1; i++) {
        xmt[i] =  i + 1;
        rcv[i] = 0;
    }

    printf ("\nMMC Single block read-write test\n");

    for (count=0;count<=256;count++){
        datasend[count]    = count;
        datareceive[count] = 0xFFFF;
    }

    /* A detailed explanation of MMC initialization is provided in mmc_setup example */
    mmc0 = MMC_open(MMC_DEV1);
    MMC_setupNative(mmc0,&Init);

    MMC_sendGoIdle(mmc0);
    for (count=0;count<4016;count++)
    	asm("	NOP");

    cardtype = MMC_sendOpCond(mmc0,0x00100000);

    if (cardtype == MMC_CARD){
       cid = &cardid;
       MMC_sendAllCID(mmc0,cid); // get the CID structure for all cards.
       rca = 10;
       card = &cardalloc;
       retVal = MMC_setRca(mmc0,card,rca);
    } else {
       cid = &cardid;
       SD_sendAllCID(mmc0,cid); // get the CID structure for all cards.
       card = &cardalloc;
       rca = SD_sendRca(mmc0,card);
       printf ("RCA sent by the SD card is 0x%x\n", rca);
    }

    /* Select the card to transfer data to/from. This step puts the card into the *
     * transfer state where it is ready to read/write data                        */

    retVal = MMC_selectCard(mmc0,card);

    printf ("Reading data from card...\n");
    retVal = MMC_read(mmc0,0x219a00,datareceive,512);
    for (count = 0; count < 6000; ++count);

    printf ("TEST PASSED\n");

    /* Call function to effect transfer */
    taskFxn();
}

void taskFxn(void)
{
    Uint16 srcAddrHi, srcAddrLo;
    Uint16 dstAddrHi, dstAddrLo;
    Uint16 i;

    /* By default, the TMS320C55xx compiler assigns all data symbols word */
    /* addresses. The DMA however, expects all addresses to be byte       */
    /* addresses. Therefore, we must shift the address by 2 in order to   */
    /* change the word address to a byte address for the DMA transfer.    */
    srcAddrHi = (Uint16)(((Uint32)(MCBSP_ADDR(DRR11))) >> 15) & 0xFFFFu;
    srcAddrLo = (Uint16)(((Uint32)(MCBSP_ADDR(DRR11))) << 1) & 0xFFFFu;
    dstAddrHi = (Uint16)(((Uint32)(&rcv)) >> 15) & 0xFFFFu;
    dstAddrLo = (Uint16)(((Uint32)(&rcv)) << 1) & 0xFFFFu;

    dmaRcvConfig.dmacssal = (DMA_AdrPtr)srcAddrLo;
    dmaRcvConfig.dmacssau = srcAddrHi;
    dmaRcvConfig.dmacdsal = (DMA_AdrPtr)dstAddrLo;
    dmaRcvConfig.dmacdsau = dstAddrHi;

    srcAddrHi = (Uint16)(((Uint32)(&xmt[0])) >> 15) & 0xFFFFu;
    srcAddrLo = (Uint16)(((Uint32)(&xmt[0])) << 1) & 0xFFFFu;
    dstAddrHi = (Uint16)(((Uint32)(MCBSP_ADDR(DXR11))) >> 15) & 0xFFFFu;
    dstAddrLo = (Uint16)(((Uint32)(MCBSP_ADDR(DXR11))) << 1) & 0xFFFFu;

    dmaXmtConfig.dmacssal = (DMA_AdrPtr)srcAddrLo;
    dmaXmtConfig.dmacssau = srcAddrHi;
    dmaXmtConfig.dmacdsal = (DMA_AdrPtr)dstAddrLo;
    dmaXmtConfig.dmacdsau = dstAddrHi;

    /* Open MCBSP Port 1 and set registers to their power on defaults */
    hMcbsp = MCBSP_open(MCBSP_PORT1, MCBSP_OPEN_RESET);

    /* Open DMA channels 4 & 5 and set regs to power on defaults */
    hDmaRcv = DMA_open(DMA_CHA4,DMA_OPEN_RESET);
    hDmaXmt = DMA_open(DMA_CHA5,DMA_OPEN_RESET);

    /* Get interrupt event associated with DMA receive and transmit */
    xmtEventId = DMA_getEventId(hDmaXmt);
    rcvEventId = DMA_getEventId(hDmaRcv);

    /* Temporarily disable interrupts and clear any pending */
    /* interrupts for MCBSP transmit */
    old_intm = IRQ_globalDisable();

    /* Clear any pending interrupts for DMA channels */
    IRQ_clear(xmtEventId);
    IRQ_clear(rcvEventId);

    /* Enable DMA interrupt in IER register */
    IRQ_enable(xmtEventId);
    IRQ_enable(rcvEventId);

    /* Set Start Of Interrupt Vector Table */
    IRQ_setVecs(0x10000);

    /* Place DMA interrupt service addresses at associate vector */
    IRQ_plug(xmtEventId,&dmaXmtIsr);
    IRQ_plug(rcvEventId,&dmaRcvIsr);

    /* Write values from configuration structure to MCBSP control regs */
    MCBSP_config(hMcbsp, &ConfigLoopBack16);

    /* Write values from configuration structure to DMA control regs */
    DMA_config(hDmaRcv,&dmaRcvConfig);
    DMA_config(hDmaXmt,&dmaXmtConfig);

#if 0
    /* Take MCBSP transmit and receive out of reset */
    MCBSP_start(hMcbsp,
                MCBSP_XMIT_START | MCBSP_RCV_START,
                0u);

    /* Prime MCBSP DXR */
    while (!(MCBSP_xrdy(hMcbsp))){
      ;
    }
    MCBSP_write16(hMcbsp,xmt[0]);

   /* Enable all maskable interrupts */
    IRQ_globalEnable();

    /* Enable DMA */
    DMA_start(hDmaRcv);
    DMA_start(hDmaXmt);

    /* Start Sample Rate Generator and Enable Frame Sync */
    MCBSP_start(hMcbsp,
                MCBSP_SRGR_START | MCBSP_SRGR_FRAMESYNC,
                0x300u);
#else
	/* Enable all maskable interrupts */
    IRQ_globalEnable();

    /* Start Sample Rate Generator and Enable Frame Sync */
    MCBSP_start(hMcbsp,
                MCBSP_SRGR_START | MCBSP_SRGR_FRAMESYNC,
                0x300u);

    /* Enable DMA */
    DMA_start(hDmaRcv);
    DMA_start(hDmaXmt);

    /* Take MCBSP transmit and receive out of reset */
    MCBSP_start(hMcbsp,
                MCBSP_XMIT_START | MCBSP_RCV_START,
                0u);
#endif
    /* Wait for DMA transfer to be complete */
    while (!transferComplete){
        ;
    }

    /*------------------------------------------*\
     * Compare values
    \*------------------------------------------*/
    for(i = 0; i <= N - 1; i++){
        if (rcv[i] != xmt[i]){
            ++err;
            break;
       }
    }

    printf ("%s\n",err?"TEST FAILED" : "TEST PASSED");

    /* Restore status of global interrupt enable flag */
    IRQ_globalRestore(old_intm);

    /* We're done with MCBSP and DMA , so close them */
    MCBSP_close(hMcbsp);
    DMA_close(hDmaRcv);
    DMA_close(hDmaXmt);
}

interrupt void dmaXmtIsr(void) {
   DMA_stop(hDmaXmt);
   IRQ_disable(xmtEventId);
}

interrupt void dmaRcvIsr(void) {
   DMA_stop(hDmaRcv);
   IRQ_disable(rcvEventId);
   transferComplete = TRUE;
}

感谢您的回答，还有我想问下retVal = MMC_read(mmc0,0x219a00,datareceive,512);这句读取SD的程序，我如何更改DMA和MCBSP的设置？我看了下关于MCBSP读SD卡的说明，貌似还要发命令什么的，我上一条回复贴上了我的代码，但是提示说需要等待版主通过才行