rt1064的spi时钟频率之间的关系是什么样的

胡骐麟

spi_clk与lpspiclk有什么区别吗，目前spi的时钟名词有，时钟频率，波特率分频，波特率，怎么理清其中关系
    ////////////////////////////////////////////////////////////////////////////////
    // Step 2: Configure the SPI fynctions
    ////////////////////////////////////////////////////////////////////////////////
    /* Notes:
      *    1. Two different clocks configured
        *       - lpspi_clk   : clocks for lpspi function module. Here, we set to 192MHz, or aound 1/5.2ns
        *       - spi_baudrate: spi_sck frequency, initially to be 4MHz. No more than lpspi_clk/2, and better be lpspi_clk/2^n
        *    2. Datasheet says, pcsToSckDelay, lastSckToPcsDelay, betweenTransferDelayInNanoSec should be at least 1cycle of lpspi_clk
    */

    u32 lpspi_clk;
    u8 lpspi_clk_divid_def = 2; // Default Clock divider = 2, therefore SPI Source Clock =192MHz as default

    u32 spi_baudrate = 8000000; //SCK->8MHz Baud=8Mbps. Noted:  SCK frequency different from LPSPI Module clock(lpspiclk)
    lpspi_master_config_t lpspi_config;

    //Setup the SPI Module Clock sources to be PLL3_PFD0/(1+5)=576Mhz/(1+5) = 96MHz
    CLOCK_SetMux(kCLOCK_LpspiMux, 1);                   // Select USB1 PLL PFD0(576MHz) as LPSPI Clock Sources
    CLOCK_SetDiv(kCLOCK_LpspiDiv, lpspi_clk_divid_def); // Default Clock divider = 35, therefore SPI Clock = 16MHz Initally

    LPSPI_Enable(M8266WIFI_INTERFACE_SPI, false);
    lpspi_clk = (CLOCK_GetFreq(kCLOCK_Usb1PllPfd0Clk) / (lpspi_clk_divid_def + 1));
    lpspi_config.baudRate = spi_baudrate;
    lpspi_config.whichPcs = kLPSPI_Pcs1;
    lpspi_config.pcsActiveHighOrLow = kLPSPI_PcsActiveLow;
    lpspi_config.bitsPerFrame = 8;
    lpspi_config.cpol = kLPSPI_ClockPolarityActiveHigh; // Require Idle Low, so Active High
    lpspi_config.cpha = kLPSPI_ClockPhaseFirstEdge;     // kLPSPI_ClockPhaseSecondEdge;
    lpspi_config.direction = kLPSPI_MsbFirst;
    lpspi_config.pinCfg = kLPSPI_SdiInSdoOut;
    lpspi_config.dataOutConfig = kLpspiDataOutRetained; // kLpspiDataOutTristate;
    lpspi_config.pcsToSckDelayInNanoSec = 5;            // The delay is (SCKPCS+1)cycles of lpspi_clk. Therefore, at least 5.02ns @ 192MHz
    lpspi_config.lastSckToPcsDelayInNanoSec = 5;        // The delay is (PCSSCK+1)cycles of lpspi_clk. Therefore, at least 5.02ns @ 192MHz
    lpspi_config.betweenTransferDelayInNanoSec = 10;    // The delya is (DBT   +2)cycles of lpspi_clk. Therefore, at least 5.02ns @ 192MHz

    LPSPI_MasterInit(M8266WIFI_INTERFACE_SPI, &lpspi_config, lpspi_clk);
    LPSPI_Enable(M8266WIFI_INTERFACE_SPI, true);
}

胡骐麟

害，放弃了，spi没有任何问题，淘宝上有一家叫alk的用它家的模块智能他们的家的例程跑起来，移植性非常差，建议没有五六年嵌入式从业经验的友友避坑

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