[参考译文] TMS320F2800157：SPI_receiveNBytes 帮助

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器件型号： TMS320F2800157
主题： C2000WARE 中讨论的其他器件

您好、

我正在将 SPI EEPROM 与我的系统集成、并且已经按照 C2000Ware 5.04 中的 SPI EEPROM 示例进行了操作。示例中未使用但引用的调用之一是 SPI_receiveNBytes。因为我想一次读一个更长的字串,我认为这种调用将是肤浅的。

我注意到该示例是围绕 EEPROM 设计的、只需要 16 位地址、我的需要 24 位地址。因此、我进行了相应修改以发送 24 位地址。这适用于 SPI_receive32Bits。

在下面的监听中、我包含这两个调用、并在 SPI_receive32Bits 和 SPI_receiveNBytes 之间交换。 snip-it 显示了 SPI_receiveNBytes 注释掉、因为我在上次运行中使用了 SPI_receive32Bits。

我的问题是两个呼叫都不会返回相同的数据。我知道 SPI_receive32 位仅接收 32 位、但接收到的这 32 位是正确的。

更多有关 SPI_receiveNBytes 的信息。我提供的长度= 8（字节）、txdly = no_delay。

您能告诉我我我在坑里的下落吗？

// Function to read data from the EEPROM
// - address is the byte address of the EEPROM
// - data is a pointer to an array of data being received
// - length is the number of characters in the array to receive
void PR_ReadData(uint32_t address, uint16_t *data, uint16_t length, uint16_t txdly)
{
     uint32_t RXdata = 0;
     CS_LOW;

    // Send the READ opcode.
    SPI_transmitByte(SPIA_BASE, READ);

    // Send EEPROM 24bit address to write data
    SPI_transmitByte(SPIA_BASE, address>>16);
    SPI_transmitByte(SPIA_BASE, address>>8);
    SPI_transmitByte(SPIA_BASE, address);

    // Receive length number of bytes
    //SPI_receiveNBytes(SPIA_BASE, data, length, txdly);

    RXdata = SPI_receive32Bits(SPIA_BASE, SPI_DATA_LITTLE_ENDIAN, DUMMY_DATA, txdly);

    CS_HIGH;
}

4 个月前

0 admin 3 个月前

TI__Guru**** 2782625 points

请注意，本文内容源自机器翻译，可能存在语法或其它翻译错误，仅供参考。如需获取准确内容，请参阅链接中的英语原文或自行翻译。

再做一些研究、我发现 SPI_receiveNBytes spi.h 中定义了以下内容

//*****************************************************************************
//
//! This macro is used to receive 'N' bytes of data
//!
//! \param base specifies the SPI module base address.
//! \param rxBuffer specifies receive buffer which will store the received bytes
//! \param numOfWords specifies the number of bytes to be received
//! \param txDelay specifies the number of serial clock cycles delay time after
//!        completion of perious word
//!
//! This function is used to receive 'N' bytes of data
//! This function uses SPI_pollingFIFOTransaction function.
//! SPI character length must be configured to 8 bits BEFORE calling the
//! function
//!
//! \return None.
//
//*****************************************************************************
#define SPI_receiveNBytes(base, rxBuffer, numOfWords, txDelay)                 \
      SPI_pollingFIFOTransaction(base, 8U,  NULL, rxBuffer, numOfWords, txDelay)

SPI_receive32Bits uses the SPI_pollingFIFOTransaction call as below

uint32_t
SPI_receive32Bits(uint32_t base, SPI_endianess endianness, uint16_t dummyData,
                  uint16_t txDelay)
{
    uint16_t i;
    uint16_t txBuffer[4];
    uint16_t rxBuffer[4];
    uint32_t rxData = 0U;

    ASSERT(dummyData <= 0xFFU);

    //
    // Empty Transmit buffer
    //
    for(i = 0U; i < 4U; i++)
    {
        txBuffer[i] = dummyData;
        rxBuffer[i] = 0U;
    }

    //
    // Send dummy words to receive data from peripheral
    // Four 8-bits make a 32-bit
    // Character length = 8
    // number of bytes = 4
    //
    SPI_pollingFIFOTransaction(base, 8U, txBuffer, rxBuffer, 4U, txDelay);

    if(endianness == SPI_DATA_LITTLE_ENDIAN)
    {
        //
        // LITTLE_ENDIAN
        //
        rxData = ((uint32_t)rxBuffer[3] << 24U) |
                 ((uint32_t)rxBuffer[2] << 16U) |
                 ((uint32_t)rxBuffer[1] << 8U)  |
                 (uint32_t)rxBuffer[0];
    }
    else
    {
        //
        // BIG_ENDIAN
        //
        rxData = ((uint32_t)rxBuffer[0] << 24U) |
                 ((uint32_t)rxBuffer[1] << 16U) |
                 ((uint32_t)rxBuffer[2] << 8U)  |
                 (uint32_t)rxBuffer[3];
    }

    return(rxData);
}

I had to create an equivalent of SPI_receive32Bits to call SPI_pollingFIFOTransaction and then it all worked.

0 admin 3 个月前

TI__Guru**** 2782625 points

请注意，本文内容源自机器翻译，可能存在语法或其它翻译错误，仅供参考。如需获取准确内容，请参阅链接中的英语原文或自行翻译。

请参阅相关文章： e2e.ti.com/.../6222598

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[参考译文] TMS320F2800157：SPI_receiveNBytes 帮助