dsk_app.c

这个例子是用来数字处理在AIC23上的线性音频数据

        MCBSP_FMKS(PCR, FSRM, EXTERNAL)         |
        MCBSP_FMKS(PCR, CLKXM, INPUT)           |
        MCBSP_FMKS(PCR, CLKRM, INPUT)           |
        MCBSP_FMKS(PCR, CLKSSTAT, DEFAULT)      |
        MCBSP_FMKS(PCR, DXSTAT, DEFAULT)        |
        MCBSP_FMKS(PCR, FSXP, ACTIVEHIGH)       |
        MCBSP_FMKS(PCR, FSRP, ACTIVEHIGH)       |
        MCBSP_FMKS(PCR, CLKXP, FALLING)         |
        MCBSP_FMKS(PCR, CLKRP, RISING)
};

/* Codec configuration settings */
AIC23_Params config = {
    0x001F, // 0 DSK6713_AIC23_LEFTINVOL  Left line input channel volume
    0x001F, // 1 DSK6713_AIC23_RIGHTINVOL Right line input channel volume
    0x00dF, // 2 DSK6713_AIC23_LEFTHPVOL  Left channel headphone volume
    0x00dF, // 3 DSK6713_AIC23_RIGHTHPVOL Right channel headphone volume
    0x0011, // 4 DSK6713_AIC23_ANAPATH    Analog audio path control
    0x0000, // 5 DSK6713_AIC23_DIGPATH    Digital audio path control
    0x0000, // 6 DSK6713_AIC23_POWERDOWN  Power down control
    0x0043, // 7 DSK6713_AIC23_DIGIF      Digital audio interface format
    0x0001, // 8 DSK6713_AIC23_SAMPLERATE Sample rate control
    0x0001  // 9 DSK6713_AIC23_DIGACT     Digital interface activation
};


/* --------------------------- main() function -------------------------- */
/*
 *  main() - The main user task.  Performs application initialization and
 *           starts the data transfer.
 */
void main()
{
    /* Initialize Board Support Library */
    DSK6713_init();

    /* Initialize LEDs and DIP switches */
    DSK6713_LED_init();
    DSK6713_DIP_init();

    /* Clear buffers */
    memset((void *)gBufferXmtPing, 0, BUFFSIZE * 4 * 2);

    AIC23_setParams(&config);  // Configure the codec

    initMcbsp();               // Initialize McBSP1 for audio transfers

    IRQ_globalDisable();       // Disable global interrupts during setup

    initEdma();                // Initialize the EDMA controller

    initIrq();                 // Initialize interrupts

    IRQ_globalEnable();        // Re-enable global interrupts
}


/* ------------------------Helper Functions ----------------------------- */

/*
 *  initMcbsp() - Initialize the McBSP for codec data transfers using the
 *                configuration define at the top of this file.
 */
void initMcbsp()
{
    /* Open the codec data McBSP */
    hMcbsp1 = MCBSP_open(MCBSP_DEV1, MCBSP_OPEN_RESET);

    /* Configure the codec to match the AIC23 data format */
    MCBSP_config(hMcbsp1, &mcbspCfg1);

    /* Start the McBSP running */
    MCBSP_start(hMcbsp1, MCBSP_XMIT_START | MCBSP_RCV_START |
        MCBSP_SRGR_START | MCBSP_SRGR_FRAMESYNC, 220);
}


/*
 *  initIrq() - Initialize and enable the DMA receive interrupt using the CSL.
 *              The interrupt service routine for this interrupt is edmaHwi.
 */
void initIrq(void)
{
    /* Enable EDMA interrupts to the CPU */
    IRQ_clear(IRQ_EVT_EDMAINT);    // Clear any pending EDMA interrupts
    IRQ_enable(IRQ_EVT_EDMAINT);   // Enable EDMA interrupt
}


/*
 *  initEdma() - Initialize the DMA controller.  Use linked transfers to
 *               automatically transition from ping to pong and visa-versa.
 */
void initEdma(void)
{
    /* Configure transmit channel */
    hEdmaXmt = EDMA_open(EDMA_CHA_XEVT1, EDMA_OPEN_RESET);  // get hEdmaXmt handle and reset channel
    hEdmaReloadXmtPing = EDMA_allocTable(-1);               // get hEdmaReloadXmtPing handle
    hEdmaReloadXmtPong = EDMA_allocTable(-1);               // get hEdmaReloadXmtPong handle

    gEdmaConfigXmt.dst = MCBSP_getXmtAddr(hMcbsp1);         // set the desination address to McBSP1 DXR

    gXmtChan = EDMA_intAlloc(-1);                           // get an open TCC
    gEdmaConfigXmt.opt |= EDMA_FMK(OPT,TCC,gXmtChan);       // set TCC to gXmtChan

    EDMA_config(hEdmaXmt, &gEdmaConfigXmt);                 // then configure the registers
    EDMA_config(hEdmaReloadXmtPing, &gEdmaConfigXmt);       // and the reload for Ping

    gEdmaConfigXmt.src = EDMA_SRC_OF(gBufferXmtPong);       // change the structure to have a source of Pong
    EDMA_config(hEdmaReloadXmtPong, &gEdmaConfigXmt);       // and configure the reload for Pong

    EDMA_link(hEdmaXmt,hEdmaReloadXmtPong);                 // link the regs to Pong
    EDMA_link(hEdmaReloadXmtPong,hEdmaReloadXmtPing);       // link Pong to Ping
    EDMA_link(hEdmaReloadXmtPing,hEdmaReloadXmtPong);       // and link Ping to Pong

    /* Configure receive channel */
    hEdmaRcv = EDMA_open(EDMA_CHA_REVT1, EDMA_OPEN_RESET);  // get hEdmaRcv handle and reset channel
    hEdmaReloadRcvPing = EDMA_allocTable(-1);               // get hEdmaReloadRcvPing handle
    hEdmaReloadRcvPong = EDMA_allocTable(-1);               // get hEdmaReloadRcvPong handle

    gEdmaConfigRcv.src = MCBSP_getRcvAddr(hMcbsp1);         // and the desination address to McBSP1 DXR

    gRcvChan = EDMA_intAlloc(-1);                           // get an open TCC
    gEdmaConfigRcv.opt |= EDMA_FMK(OPT,TCC,gRcvChan);       // set TCC to gRcvChan

    EDMA_config(hEdmaRcv, &gEdmaConfigRcv);                 // then configure the registers
    EDMA_config(hEdmaReloadRcvPing, &gEdmaConfigRcv);       // and the reload for Ping

    gEdmaConfigRcv.dst = EDMA_DST_OF(gBufferRcvPong);       // change the structure to have a destination of Pong
    EDMA_config(hEdmaReloadRcvPong, &gEdmaConfigRcv);       // and configure the reload for Pong

    EDMA_link(hEdmaRcv,hEdmaReloadRcvPong);                 // link the regs to Pong
    EDMA_link(hEdmaReloadRcvPong,hEdmaReloadRcvPing);       // link Pong to Ping
    EDMA_link(hEdmaReloadRcvPing,hEdmaReloadRcvPong);       // and link Ping to Pong

    /* Enable interrupts in the EDMA controller */
    EDMA_intClear(gXmtChan);
    EDMA_intClear(gRcvChan);                                // clear any possible spurious interrupts

    EDMA_intEnable(gXmtChan);                               // enable EDMA interrupts (CIER)
    EDMA_intEnable(gRcvChan);                               // enable EDMA interrupts (CIER)

    EDMA_enableChannel(hEdmaXmt);                           // enable EDMA channel
    EDMA_enableChannel(hEdmaRcv);                           // enable EDMA channel

    /* Do a dummy write to generate the first McBSP transmit event */
    MCBSP_write(hMcbsp1, 0);
}


/*
 *  copyData() - Copy one buffer with length elements to another.
 */
void copyData(Int16 *inbuf, Int16 *outbuf, Int16 length)
{
    Int16 i = 0;

    for (i = 0; i < length; i++) {
        outbuf[i]  = inbuf[i] ;
    }
}


/* ---------------------- Interrupt Service Routines -------------------- */

/*
 *  edmaHwi() - Interrupt service routine for the DMA transfer.  It is
 *              triggered when a complete DMA receive frame has been
 *              transferred.   The edmaHwi ISR is inserted into the interrupt
 *              vector table at compile time through a setting in the DSP/BIOS
 *              configuration under Scheduling --> HWI --> HWI_INT8.  edmaHwi
 *              uses the DSP/BIOS Dispatcher to save register state and make
 *              sure the ISR co-exists with other DSP/BIOS functions.
 */
void edmaHwi(void)
{
    static Uint32 pingOrPong = PING;  // Ping-pong state variable
    static Int16 xmtdone = 0, rcvdone = 0;

    /* Check CIPR to see which transfer completed */
    if (EDMA_intTest(gXmtChan))
    {
        EDMA_intClear(gXmtChan);
        xmtdone = 1;
    }
    if (EDMA_intTest(gRcvChan))
    {
        EDMA_intClear(gRcvChan);
        rcvdone = 1;
    }

    /* If both transfers complete, signal processBufferSwi to handle */
    if (xmtdone && rcvdone)
    {
        if (pingOrPong==PING)
        {
            SWI_or(&processBufferSwi, PING);
            pingOrPong = PONG;
        } else
        {
            SWI_or(&processBufferSwi, PONG);
            pingOrPong = PING;
        }
        rcvdone = 0;
        xmtdone = 0;
    }
}


/* ------------------------------- Threads ------------------------------ */

/*
 *  processBuffer() - Process audio data once it has been received.
 */
void processBuffer(void)
{
    Uint32 pingPong;

    /* Get contents of mailbox posted by edmaHwi */
    pingPong =  SWI_getmbox();

    /* Copy data from transmit to receive, could process audio here */
    if (pingPong == PING) {
        /* Toggle LED #3 as a visual cue */
        DSK6713_LED_toggle(3);

        /* Copy receive PING buffer to transmit PING buffer */
        copyData(gBufferRcvPing, gBufferXmtPing, BUFFSIZE);
    } else {
        /* Toggle LED #2 as a visual cue */
        DSK6713_LED_toggle(2);

        /* Copy receive PONG buffer to transmit PONG buffer */
        copyData(gBufferRcvPong, gBufferXmtPong, BUFFSIZE);
    }
}

/*
 *  blinkLED() - Periodic thread (PRD) that toggles LED #0 every 500ms if
 *               DIP switch #0 is depressed.  The thread is configured
 *               in the DSP/BIOS configuration tool under Scheduling -->
 *               PRD --> PRD_blinkLed.  The period is set there at 500
 *               ticks, with each tick corresponding to 1ms in real
 *               time.
 */
void blinkLED(void)
{
    /* Toggle LED #0 if DIP switch #0 is off (depressed) */
    if (!DSK6713_DIP_get(0))
        DSK6713_LED_toggle(0);
}


/*
 *  load() - PRD that simulates a 20-25% dummy load on a 225MHz 6713 if
 *           DIP switch #1 is depressed.  The thread is configured in
 *           the DSP/BIOS configuration tool under Scheduling --> PRD
 *           PRD_load.  The period is set there at 10 ticks, which each tick
 *           corresponding to 1ms in real time.
 */
void load(void)
{
    volatile Uint32 i;

    if (!DSK6713_DIP_get(1))
        for (i = 0; i < 30000; i++);
}