McBSP和DMA接口的问题，不明白，希望各位指点下

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reporter发表于 2014-5-9 11:32 | 只看该作者

McBSP和DMA接口的问题，不明白，希望各位指点下

最近在学McBSP和DMA，TI的官方例程中，有一个例程是
McBSP工作在数字回环模式下，同步接收DMA通道2的数据，在这个例程中有个问题不明白

&nbsp; &nbsp; /* Wait for DMA transfer to be complete */
&nbsp; &nbsp; while (!DMA_FGETH(mhDma,DMACSR,FRAME)) {
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;;&nbsp; &nbsp;
&nbsp; &nbsp; }//为什么这条语句结束才表明数据收发完成?
&nbsp; &nbsp;
这里的“同步”是什么意思？是McBSP模块内部进行数据传输的同时，还可以接收来自DMA的数据，如果是这样的话，接收的DMA数据是
作为写入到DXR中的数据还是其他的？
*************************************************************************************************************************
/*
* Copyright (C) 2003 Texas Instruments Incorporated
* All Rights Reserved
*/
/*
*---------main_dma3.c---------
* This example places the MCBSP in digital loopback mode and
* syncs MCBSP receive with DMA channel 2.&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;
* The example uses predefined CSL macros and symbolic&nbsp; &nbsp;&nbsp; &nbsp;
* constants to create the initialization values needed for&nbsp;&nbsp;
* the MCBSP and DMA control registers to effect the transfer
*/
/*************************************************************************
*实验说明：将MCBSP置于数字回环模式，并且同步接收DMA通道2的数据，实验中仍然
*使用预先定义的CSL宏和符号常量来进行相关控制寄存器的初始化
*************************************************************************/
#include &lt;stdio.h&gt;

#include &lt;csl_mcbsp.h&gt;
#include &lt;csl_dma.h&gt;
#include &lt;csl_irq.h&gt;

//---------Global constants---------
#define N&nbsp; &nbsp;&nbsp; &nbsp; 128

//---------Global data definition---------
/* Define transmit and receive buffers */
#pragma DATA_SECTION(rcv,&quot;dmaMem&quot;)
Uint16 xmt[N], rcv[N];

&nbsp;&nbsp;MCBSP_Config ConfigLoopBack16= {
&nbsp;&nbsp;MCBSP_SPCR1_RMK(
&nbsp; &nbsp; MCBSP_SPCR1_DLB_ON,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* DLB&nbsp; &nbsp; = 1 */
&nbsp; &nbsp; MCBSP_SPCR1_RJUST_RZF,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* RJUST&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR1_CLKSTP_DISABLE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* CLKSTP = 0 */
&nbsp; &nbsp; MCBSP_SPCR1_DXENA_NA,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* DXENA&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR1_ABIS_DISABLE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* ABIS&nbsp; &nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR1_RINTM_RRDY,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* RINTM&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; 0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* RSYNCER = 0 */
&nbsp; &nbsp; MCBSP_SPCR1_RRST_DISABLE&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* RRST&nbsp; &nbsp;= 0 */
&nbsp; &nbsp;),
&nbsp; &nbsp; MCBSP_SPCR2_RMK(
&nbsp; &nbsp; MCBSP_SPCR2_FREE_NO,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FREE&nbsp; &nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR2_SOFT_NO,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* SOFT&nbsp; &nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR2_FRST_RESET,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FRST&nbsp; &nbsp;= 0 帧同步*/
&nbsp; &nbsp; MCBSP_SPCR2_GRST_RESET,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* GRST&nbsp; &nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SPCR2_XINTM_XRDY,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* XINTM&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; 0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* XSYNCER = N/A */
&nbsp; &nbsp; MCBSP_SPCR2_XRST_DISABLE&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* XRST&nbsp; &nbsp;= 0 */
&nbsp; &nbsp;),
&nbsp;&nbsp;MCBSP_RCR1_RMK(
&nbsp;&nbsp;MCBSP_RCR1_RFRLEN1_OF(0),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* RFRLEN1 = 0 */
&nbsp;&nbsp;MCBSP_RCR1_RWDLEN1_16BIT&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* RWDLEN1 = 5 */
&nbsp;&nbsp;),
MCBSP_RCR2_RMK(&nbsp; &nbsp;
&nbsp; &nbsp; MCBSP_RCR2_RPHASE_SINGLE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* RPHASE&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; MCBSP_RCR2_RFRLEN2_OF(0),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* RFRLEN2 = 0 */
&nbsp; &nbsp; MCBSP_RCR2_RWDLEN2_8BIT,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* RWDLEN2 = 0 */
&nbsp; &nbsp; MCBSP_RCR2_RCOMPAND_MSB,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* RCOMPAND = 0 */
&nbsp; &nbsp; MCBSP_RCR2_RFIG_YES,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* RFIG&nbsp; &nbsp; = 0 */
&nbsp; &nbsp; MCBSP_RCR2_RDATDLY_0BIT&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* RDATDLY = 0 数据接收延时*/
&nbsp; &nbsp; ),&nbsp;&nbsp;
&nbsp; &nbsp;MCBSP_XCR1_RMK(&nbsp; &nbsp;
&nbsp; &nbsp; MCBSP_XCR1_XFRLEN1_OF(0),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* XFRLEN1 = 0 */
&nbsp; &nbsp; MCBSP_XCR1_XWDLEN1_16BIT&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* XWDLEN1 = 5 发送阶段1的字长为16位*/
&nbsp; &nbsp;
),&nbsp; &nbsp;
MCBSP_XCR2_RMK(&nbsp; &nbsp;
&nbsp; &nbsp; MCBSP_XCR2_XPHASE_SINGLE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* XPHASE&nbsp;&nbsp;= 0 */
&nbsp; &nbsp; MCBSP_XCR2_XFRLEN2_OF(0),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* XFRLEN2 = 0 */
&nbsp; &nbsp; MCBSP_XCR2_XWDLEN2_8BIT,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* XWDLEN2 = 0 */
&nbsp; &nbsp; MCBSP_XCR2_XCOMPAND_MSB,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* XCOMPAND = 0 */
&nbsp; &nbsp; MCBSP_XCR2_XFIG_YES,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* XFIG&nbsp; &nbsp; = 0 */
&nbsp; &nbsp; MCBSP_XCR2_XDATDLY_0BIT&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* XDATDLY = 0 */
&nbsp;&nbsp;),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;
MCBSP_SRGR1_RMK(
&nbsp; &nbsp;MCBSP_SRGR1_FWID_OF(1),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FWID&nbsp; &nbsp; = 1 */
&nbsp; &nbsp;MCBSP_SRGR1_CLKGDV_OF(1)&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* CLKGDV&nbsp;&nbsp;= 1 */
),&nbsp; &nbsp;
MCBSP_SRGR2_RMK(&nbsp;&nbsp;
&nbsp; &nbsp; MCBSP_SRGR2_GSYNC_FREE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FREE&nbsp; &nbsp; = 0 */
&nbsp; &nbsp; MCBSP_SRGR2_CLKSP_RISING,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* CLKSP&nbsp; &nbsp;= 0 */
&nbsp; &nbsp; MCBSP_SRGR2_CLKSM_INTERNAL,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* CLKSM&nbsp; &nbsp;= 1 */
&nbsp; &nbsp; MCBSP_SRGR2_FSGM_DXR2XSR,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* FSGM&nbsp; &nbsp; = 0 */
&nbsp; &nbsp; MCBSP_SRGR2_FPER_OF(15)&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FPER&nbsp; &nbsp; = 0 */
),&nbsp;&nbsp;
MCBSP_MCR1_DEFAULT,
MCBSP_MCR2_DEFAULT,
MCBSP_PCR_RMK(
&nbsp; &nbsp;MCBSP_PCR_IDLEEN_RESET,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* IDLEEN&nbsp; &nbsp;= 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_XIOEN_SP,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* XIOEN&nbsp; &nbsp; = 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_RIOEN_SP,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* RIOEN&nbsp; &nbsp; = 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_FSXM_INTERNAL,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FSXM&nbsp; &nbsp;&nbsp;&nbsp;= 1&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_FSRM_EXTERNAL,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* FSRM&nbsp; &nbsp;&nbsp;&nbsp;= 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_CLKXM_OUTPUT,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* CLKXM&nbsp; &nbsp; = 1&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_CLKRM_INPUT,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* CLKRM&nbsp; &nbsp; = 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_SCLKME_NO,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* SCLKME&nbsp; &nbsp;= 0&nbsp; &nbsp;*/
&nbsp; &nbsp;0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* DXSTAT = N/A&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_FSXP_ACTIVEHIGH,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* FSXP&nbsp; &nbsp;&nbsp;&nbsp;= 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_FSRP_ACTIVEHIGH,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* FSRP&nbsp; &nbsp;&nbsp;&nbsp;= 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_CLKXP_RISING,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* CLKXP&nbsp; &nbsp; = 0&nbsp; &nbsp;*/
&nbsp; &nbsp;MCBSP_PCR_CLKRP_FALLING&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* CLKRP&nbsp; &nbsp; = 0&nbsp; &nbsp;*/
),
MCBSP_RCERA_DEFAULT,
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,&nbsp;&nbsp;
MCBSP_XCERE_DEFAULT,
MCBSP_XCERF_DEFAULT,&nbsp;&nbsp;
MCBSP_XCERG_DEFAULT,
MCBSP_XCERH_DEFAULT
};&nbsp; &nbsp;&nbsp;&nbsp;

/* Create DMA Receive Side Configuration */
DMA_Config&nbsp;&nbsp;dmaConfig = {
&nbsp;&nbsp;DMA_DMACSDP_RMK(
&nbsp; &nbsp; DMA_DMACSDP_DSTBEN_NOBURST,
&nbsp; &nbsp; DMA_DMACSDP_DSTPACK_OFF,
&nbsp; &nbsp; DMA_DMACSDP_DST_DARAM,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/*目的端口为DARAM*/
&nbsp; &nbsp; DMA_DMACSDP_SRCBEN_NOBURST,
&nbsp; &nbsp; DMA_DMACSDP_SRCPACK_OFF,
&nbsp; &nbsp; DMA_DMACSDP_SRC_PERIPH,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /*源端口为外设*/
&nbsp; &nbsp; DMA_DMACSDP_DATATYPE_16BIT
&nbsp;&nbsp;),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* DMACSDP&nbsp;&nbsp;*/
&nbsp;&nbsp;DMA_DMACCR_RMK(
&nbsp; &nbsp; DMA_DMACCR_DSTAMODE_POSTINC,
&nbsp; &nbsp; DMA_DMACCR_SRCAMODE_CONST,
&nbsp; &nbsp; DMA_DMACCR_ENDPROG_ON,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /*传输过程可以对配置寄存器进行编程*/
&nbsp; &nbsp; DMA_DMACCR_REPEAT_OFF,
&nbsp; &nbsp; DMA_DMACCR_AUTOINIT_OFF,
&nbsp; &nbsp; DMA_DMACCR_EN_STOP,
&nbsp; &nbsp; DMA_DMACCR_PRIO_LOW,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /*通道优先级低*/
&nbsp; &nbsp; DMA_DMACCR_FS_DISABLE,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /*帧同步禁止*/
&nbsp; &nbsp; DMA_DMACCR_SYNC_REVT1&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/*DMA同步事件*/
&nbsp;&nbsp;),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* DMACCR&nbsp; &nbsp;*/
&nbsp;&nbsp;DMA_DMACICR_RMK(
&nbsp; &nbsp; DMA_DMACICR_BLOCKIE_OFF,
&nbsp; &nbsp; DMA_DMACICR_LASTIE_OFF,
&nbsp; &nbsp; DMA_DMACICR_FRAMEIE_ON,　　　/*半帧中断使能*/
&nbsp; &nbsp; DMA_DMACICR_FIRSTHALFIE_OFF,
&nbsp; &nbsp; DMA_DMACICR_DROPIE_OFF,&nbsp; &nbsp;&nbsp; &nbsp;/*同步事件旁落使能关闭*/
&nbsp; &nbsp; DMA_DMACICR_TIMEOUTIE_OFF&nbsp; &nbsp;/*超时中断使能关闭*/
&nbsp;&nbsp;),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;/* DMACICR&nbsp;&nbsp;*/
&nbsp; &nbsp; (DMA_AdrPtr)(MCBSP_ADDR(DRR11)),&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* DMACSSAL */
&nbsp; &nbsp; 0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACSSAU */
&nbsp; &nbsp; (DMA_AdrPtr)&amp;rcv,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACDSAL */
&nbsp; &nbsp; 0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACDSAU */
&nbsp; &nbsp; N,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACEN&nbsp; &nbsp;*/
&nbsp; &nbsp; 1,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACFN&nbsp; &nbsp;*/
&nbsp; &nbsp; 0,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; /* DMACFI&nbsp; &nbsp;*/
&nbsp; &nbsp; 0&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;/* DMACEI&nbsp; &nbsp;*/
};

/* Define a DMA_Handle object to be used with DMA_open function */
DMA_Handle mhDma;

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

volatile Uint16 xfrCnt = 0;
Uint16 err = 0;
Uint16 old_intm;
Uint16 xmtEventId;

//---------Function prototypes---------
/* Protoype for MCBSP transmit interrupt function */
interrupt void mcbspIsr(void);
void taskFxn(void);

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

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

&nbsp; &nbsp; /* Initialize data for transfer */
&nbsp; &nbsp; for (i = 0; i &lt;= N - 1; i++) {&nbsp;&nbsp;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;xmt =&nbsp;&nbsp;i + 1;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;rcv = 0;
&nbsp; &nbsp; }

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

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

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

&nbsp; &nbsp; dmaConfig.dmacssal = (DMA_AdrPtr)srcAddrLo;
&nbsp; &nbsp; dmaConfig.dmacssau = srcAddrHi;
&nbsp; &nbsp; dmaConfig.dmacdsal = (DMA_AdrPtr)dstAddrLo;
&nbsp; &nbsp; dmaConfig.dmacdsau = dstAddrHi;

&nbsp; &nbsp; /* Open MCBSP Port 1 and set registers to their power on defaults */
&nbsp; &nbsp; mhMcbsp = MCBSP_open(MCBSP_PORT1, MCBSP_OPEN_RESET);
&nbsp; &nbsp;
&nbsp; &nbsp; /* Get interrupt event assoicated MCBSP transmit */
&nbsp; &nbsp; xmtEventId = MCBSP_getXmtEventId(mhMcbsp);
&nbsp; &nbsp;
&nbsp; &nbsp; /* Temporarily disable interrupts and clear any pending */
&nbsp; &nbsp; /* interrupts for MCBSP transmit */
&nbsp; &nbsp; old_intm = IRQ_globalDisable();
&nbsp; &nbsp; IRQ_clear(xmtEventId);

&nbsp; &nbsp; /* Enable MCBSP transmit interrupt in IER register */
&nbsp; &nbsp; IRQ_enable(xmtEventId);
&nbsp; &nbsp;
&nbsp; &nbsp; /* Set Start Of Interrupt Vector Table */
&nbsp; &nbsp; IRQ_setVecs(0x10000);

&nbsp; &nbsp; /* Place address for MCBSP transmit interrupt service routine */
&nbsp; &nbsp; /* in associated vector location */
&nbsp; &nbsp; IRQ_plug(xmtEventId,&amp;mcbspIsr);

&nbsp; &nbsp; /* Open DMA Channel 2 and set registers to their power on defaults */
&nbsp; &nbsp; mhDma = DMA_open(DMA_CHA2,DMA_OPEN_RESET);&nbsp; &nbsp;

&nbsp; &nbsp; /* Write values from configuration structure to MCBSP control regs */
&nbsp; &nbsp; MCBSP_config(mhMcbsp, &amp;ConfigLoopBack16);
&nbsp; &nbsp;
&nbsp; &nbsp; /* Write values from configuration structure to DMA control regs */
&nbsp; &nbsp; DMA_config(mhDma,&amp;dmaConfig);
&nbsp; &nbsp;
&nbsp; &nbsp; /* Enable all maskable interrupts */
&nbsp; &nbsp; IRQ_globalEnable();

&nbsp; &nbsp; /* Start MCBSP */
&nbsp; &nbsp; MCBSP_start(mhMcbsp,&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;MCBSP_SRGR_START|MCBSP_SRGR_FRAMESYNC,0x300u);

&nbsp; &nbsp; /* Enable DMA */
&nbsp; &nbsp; DMA_start(mhDma);
&nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; /* Take MCBSP transmit annd receive out of reset 发送和接收复位*/
&nbsp; &nbsp; MCBSP_start(mhMcbsp,
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; MCBSP_XMIT_START| MCBSP_RCV_START,&nbsp;&nbsp;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; 0);

&nbsp; &nbsp; /* Wait for DMA transfer to be complete */
&nbsp; &nbsp; while (!DMA_FGETH(mhDma,DMACSR,FRAME)) {
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;;&nbsp; &nbsp;
&nbsp; &nbsp; }//为什么这条语句结束才表明数据收发完成?
&nbsp; &nbsp;
&nbsp; &nbsp; /*------------------------------------------*\
&nbsp; &nbsp;&nbsp;&nbsp;* Compare values 所有数据发送和接收都完毕之后，
&nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp;检测数据收发有没有错误
&nbsp; &nbsp; \*------------------------------------------*/&nbsp; &nbsp;
&nbsp; &nbsp; for(i = 0; i &lt;= N - 1; i++){
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;if (rcv != xmt){
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;++err;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;break;
&nbsp; &nbsp;&nbsp; &nbsp; }
&nbsp; &nbsp; }

&nbsp; &nbsp; printf (&quot;%s\n&quot;,err?&quot;TEST FAILED&quot; : &quot;TEST PASSED&quot;);

&nbsp; &nbsp; /* Restore status of global interrupt enable flag */
&nbsp; &nbsp; IRQ_globalRestore(old_intm);
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; /* We're done with MCBSP and DMA , so close them */
&nbsp; &nbsp; MCBSP_close(mhMcbsp);
&nbsp; &nbsp; DMA_close(mhDma);&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;
}

/* MCBSP transmit interrupt service routine */
/*MCBSP发送中断服务子程序*/
interrupt void mcbspIsr(void) {
&nbsp;&nbsp;
&nbsp;&nbsp;if (xfrCnt &lt; N) {
&nbsp; &nbsp;&nbsp;&nbsp;MCBSP_write16(mhMcbsp,xmt[xfrCnt]); /*当发送准备好后，进入中断写数据*/
&nbsp; &nbsp;&nbsp; &nbsp;++xfrCnt;
&nbsp;&nbsp;}
&nbsp;&nbsp;else {
&nbsp; &nbsp;&nbsp;&nbsp;MCBSP_FSETH(mhMcbsp,SPCR2,XRST,0);
&nbsp;&nbsp;}
}

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