C6748 SPI 访问外部FRAM 问题

您好， C6748 SPI1 外接了一片FRAM，本人参考了Processor SDK RTOS 06_03_00_106中SPI loopback的用例，FRAM_CS连接到SPI1_SCS[0], pin脚多路复用已配置成SPI模式，尝试利用FRAM的RDID命令读取device ID， 修改的代码如下:

#define SPI_INS_FRAM      1

#define SPI_PORT_FRAM     1

#define FRAM_ID_NUM_BYTES           (9U)

#pragma DATA_ALIGN (txBuf, 128)

uint8_t txBuf;

#pragma DATA_ALIGN (rxBuf, 128)

uint8_t rxBuf[FRAM_ID_NUM_BYTES];

/*

*  ======== SPI test function ========

*/

voidspi_test()

{

    Board_initSPI();

   bool            testPassed =true;

    uint32_t        xferEnable, len, loop = 1;

    uint32_t        count = 0;

    uint32_t        terminateXfer = 0;

   bool            retVal;

    uint32_t        spi;

    /* SPI params structure */

    SPI_Params      spiParamsFram;

    /* SPI handle */

    SPI_Handle      framHandle;

    /* SPI transaction structure */

    SPI_Transaction transactionFram;

    /* SPI Hardware attributes */

    SPI_v0_HWAttrs     spi_cfg_fram;

    /* Get the default SPI init configurations */

    SPI_socGetInitCfg(SPI_INS_FRAM, &spi_cfg_fram);

    /* Set the DMA related init config */

   spi_cfg_fram.pinMode    = SPI_PINMODE_4_PIN;

    spi_cfg_fram.edmaHandle = SPIApp_edmaInit();

    spi_cfg_fram.dmaMode    = TRUE;

    spi_cfg_fram.enableIntr =false;

    SPI_socSetInitCfg(SPI_INS_FRAM, &spi_cfg_fram);

    /* Init SPI driver */

    SPI_init();

    /* Open the Board flash NOR device with the test SPI port

       and use the default SPI configurations */

    SPI_Params_init(&spiParamsFram);

    /* Config SPI params*/

    spiParamsFram.transferMode = SPI_MODE_BLOCKING;

    spiParamsFram.frameFormat = SPI_POL0_PHA0;

    spiParamsFram.dataSize  = 8;

    spiParamsFram.bitRate = FRAM_FREQ;   //30MHz

    framHandle = (SPI_Handle)SPI_open(SPI_PORT_FRAM, &spiParamsFram);

   if (!framHandle)

    {

        testPassed =false;

        System_printf("\n no spi framHandle.\n");

    }

    /* Enable transfer */

    xferEnable = 1;

    SPI_control(framHandle, SPI_V0_CMD_XFER_ACTIVATE, (void *)&xferEnable);

    txBuf = FRAM_RDID;   //read fram device ID cmd

    len = FRAM_ID_NUM_BYTES;    // 9 bytes

    transactionFram.txBuf = (void *)&txBuf;

    transactionFram.rxBuf = (void *)&rxBuf[0];

    transactionFram.count = len;

    transactionFram.arg = NULL;

    retVal = SPI_transfer(framHandle, &transactionFram);

   for (count = 0; count < FRAM_ID_NUM_BYTES; count++)

    {

        System_printf("Received Data : %x. \n",rxBuf[count]);

    }

    SPI_close(framHandle);

}

最终获取到的rxBuf全为0xFFh，并不是期望的 FRAM Device ID, 请问是哪里出了问题还是SDK提供的接口使用不当

同时参考nor_spi.c的代码 分别写入RDID 命令再进行读取操作，代码如下：

// write RDID cmd

txBuf = FRAM_RDID;

len = 1;
transactionFram.txBuf = (void *)&txBuf;
transactionFram.rxBuf = NULL;
transactionFram.count = len;
transactionFram.arg = NULL;

retVal = SPI_transfer(framHandle, &transactionFram);

// read device ID

len = FRAM_ID_NUM_BYTES;
transactionFram.txBuf = NULL;
transactionFram.rxBuf = (void *)&rxBuf[0];
transactionFram.count = len;
transactionFram.arg = NULL;

retVal = SPI_transfer(framHandle, &transactionFram);

然而在运行到第二次SPI_transfer中时(read device ID), 跑进了

if (overflow != FALSE) {
Error_raise(NULL, Hwi_E_stackOverflow, 0, 0);
}

请问这种对SPI接口的使用是有什么问题？

感谢各位的指点和解答

kaijie zhang：

回复 Shine:

FRAM支持SPI mode 0 (0, 0) and mode 3 (1, 1)， 我配置了spiParamsFram.frameFormat = SPI_POL0_PHA0;

kaijie zhang：

调试发现将SPI_v0_HWAttrs中的dmaMode置False，nor_spi的示例可以运行，但是device ID依然读取错误

kaijie zhang：

回复 Shine:

十分感谢回答 我重新对照了C6748 和FRAM 的 SPI时序模式， 修改之后读取正常了

Shine：

回复 kaijie zhang:

非常高兴您的问题解决了，感谢分享！