[参考译文] TMS320F28375S：McBSP 通过 DMA 发送四个信号、每个信号为32位、应该如何配置

https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1236639/tms320f28375s-mcbsp-sends-four-signals-through-dma-each-signal-is-32bits-how-should-it-be-configured

void configDMA32Channel1()
{
    //
    // Configure DMA Channel 1
    //
    DMA_disableInterrupt(DMA_CH1_BASE);

    //
    // Configure 2 word per burst. Increment one 16-bit address between words
    // for src & dest address.
    //
    DMA_configBurst(DMA_CH1_BASE, 2U, 1U, 1U);

    //
    // Configure 63 bursts per transfer. For src move to next word in buffer
    // after each word in a burst. For dest go back to DXR2.
    //
    DMA_configTransfer(DMA_CH1_BASE, 64, 1, 0xFFFF);

    //
    // Src start address = buffer & dest start address = MCBSPA DXR
    //
    DMA_configAddresses(DMA_CH1_BASE,(const void*)(MCBSPA_BASE + MCBSP_O_DXR2),
                        (const void*)(&txData[0]));

    //
    // Clear peripheral interrupt event flag.
    //
    DMA_clearTriggerFlag(DMA_CH1_BASE);

    //
    // Clear sync error flag.
    //
    DMA_clearErrorFlag(DMA_CH1_BASE);

    //
    // Configure wrap size to maximum to avoid wrapping.
    //
    DMA_configWrap(DMA_CH1_BASE, 0x10000U, 0, 0x10000U, 0);

    //
    // Enable channel interrupt.
    //
    DMA_enableInterrupt(DMA_CH1_BASE);

    //
    // Interrupt at end of the transfer.
    //
    DMA_setInterruptMode(DMA_CH1_BASE, DMA_INT_AT_END);

    //
    // Enable selected peripheral trigger to start a DMA transfer on DMA
    // channel 1.
    //
    DMA_enableTrigger(DMA_CH1_BASE);

    //
    // Configure DMA trigger source as McBSPA Tx EVT.
    //
    DMA_configMode(DMA_CH1_BASE, DMA_TRIGGER_MCBSPAMXEVT, 0);

    //
    // Clear any spurious Peripheral interrupts flags.
    //
    DMA_clearTriggerFlag(DMA_CH1_BASE);

这是 DMA 的配置。

void initMcBSPA()
{
    //
    // Reset FS generator, sample rate generator, transmitter & receiver.
    //
    McBSP_resetFrameSyncLogic(MCBSPA_BASE);
    McBSP_resetSampleRateGenerator(MCBSPA_BASE);
    McBSP_resetTransmitter(MCBSPA_BASE);
    McBSP_resetReceiver(MCBSPA_BASE);

    //
    // Set Rx sign-extension and justification mode.设置左对齐，补充零
    //
    McBSP_setRxSignExtension(MCBSPA_BASE, MCBSP_LEFT_JUSTIFY_FILL_ZER0);

    //
    // Enable DLB mode. Comment out for non-DLB mode.
    //
    //McBSP_enableLoopback(MCBSPA_BASE);

    //
    // Set Rx & Tx delay to 1 cycle. 发送和接受数据都延迟0位
    //
    McBSP_setRxDataDelayBits(MCBSPA_BASE, MCBSP_DATA_DELAY_BIT_0);
    McBSP_setTxDataDelayBits(MCBSPA_BASE, MCBSP_DATA_DELAY_BIT_0);

    //
    // Set CLKX & FSX source as sample rate generator. 选择发送时钟和帧同步都来自于内部时钟
    //
    McBSP_setTxClockSource(MCBSPA_BASE, MCBSP_INTERNAL_TX_CLOCK_SOURCE);
    McBSP_setTxFrameSyncSource(MCBSPA_BASE, MCBSP_TX_INTERNAL_FRAME_SYNC_SOURCE);

    McBSP_setRxFrameSyncSource(MCBSPA_BASE, MCBSP_RX_EXTERNAL_FRAME_SYNC_SOURCE);
    McBSP_setRxClockSource(MCBSPA_BASE, MCBSP_EXTERNAL_RX_CLOCK_SOURCE);
    //
    // Configure McBSP data behaviour. 设置为单相帧，每个字有32位，每个帧有4个字
    //
    McBSP_setRxDataSize(MCBSPA_BASE, MCBSP_PHASE_ONE_FRAME,
                        MCBSP_BITS_PER_WORD_32, 3);
    McBSP_setTxDataSize(MCBSPA_BASE, MCBSP_PHASE_ONE_FRAME,
                        MCBSP_BITS_PER_WORD_32, 3);

    //
    // Set frame-sync pulse period.
    //
    McBSP_setFrameSyncPulsePeriod(MCBSPA_BASE, 127);

    //
    // Set frame-sync pulse width.
    //
    McBSP_setFrameSyncPulseWidthDivider(MCBSPA_BASE, 0);

    //
    // Set the trigger source for internally generated frame-sync pulse. 发送帧同步由采样率生成器产生
    //
    McBSP_setTxInternalFrameSyncSource(MCBSPA_BASE,
                                       MCBSP_TX_INTERNAL_FRAME_SYNC_SRG);

    //
    // Set LSPCLK as input source for sample rate generator.
    //
    McBSP_setTxSRGClockSource(MCBSPA_BASE, MCBSP_SRG_TX_CLOCK_SOURCE_LSPCLK);

 //   McBSP_setRxSRGClockSource(MCBSPA_BASE, MCBSP_SRG_RX_CLOCK_SOURCE_MCLKX_PIN);
    //
    // Set Divide down value for CLKG.
    //
    McBSP_setSRGDataClockDivider(MCBSPA_BASE, 3);

    //
    // Set no external clock sync for CLKG.
    //
    McBSP_disableSRGSyncFSR(MCBSPA_BASE);

    //
    // Enable Tx and Rx interrupts.
    //
    McBSP_enableRxInterrupt(MCBSPA_BASE);
    McBSP_enableTxInterrupt(MCBSPA_BASE);

    //
    // Wait for CPU cycles equivalent to 2 SRG cycles-init delay.
    // Total cycles required = 2*(SYSCLK/LSPCLK). In this example
    // LSPCLK = SYSCLK/4.
    //
    MCBSP_CYCLE_NOP(8);

    //
    // Enable Sample rate generator and wait for at least 2 CLKG clock cycles.
    //
    McBSP_enableSampleRateGenerator(MCBSPA_BASE);

    //
    // Wait for CPU cycles equivalent to 2 CLKG cycles-init delay.
    // Total cycles required = 2*(SYSCLK/(LSPCLK/(1+CLKGDV_VAL))). In this
    // example LSPCLK = SYSCLK/4 and CLKGDV_VAL = 1.
    //
    MCBSP_CYCLE_NOP(16);

    //
    // Release Rx, Tx from reset.
    //
    McBSP_enableReceiver(MCBSPA_BASE);
    McBSP_enableTransmitter(MCBSPA_BASE);
    McBSP_enableFrameSyncLogic(MCBSPA_BASE);
}

这是 McBSP 的配置。

--

谢谢、此致

耶鲁