SPI 核软件调试记录

SPI 核软件调试记录

1.首先说说int SpiFlashWaitForFlashReady(void)这一函数，基本上其它函数在执行的时候，都会事先执行一次此函数。

   因为此函数的作用主要是用来等待，所以整个语句在一个循环里面。第一步是检测spi flash 的状态，若spi flash 已经完成了上一次传送，

  状态为XST_SUCCESS,否则，函数直接返回XST_FAILURE 即not ready。检测ReadBuffer[1]中的值 若果为0，则break循环，函数返回XST_SUCCESS

  代码内容如下：

 /*****************************************************************************/
 /**
 *
 * This function waits till the Numonyx serial Flash is ready to accept next
 * command.
 *
 * @param    None
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        This function reads the status register of the Buffer and waits
 *.        till the WIP bit of the status register becomes 0.
 *
 ******************************************************************************/
 int SpiFlashWaitForFlashReady(void)
 {
     int Status;
     u8 StatusReg;

     while() {

         /*
          * Get the Status Register. The status register content is
          * stored at the second byte pointed by the ReadBuffer.
          */
         Status = SpiFlashGetStatus(&Spi);
         if(Status != XST_SUCCESS) {
             return XST_FAILURE;
         }

         /*
          * Check if the flash is ready to accept the next command.
          * If so break.
          */
         StatusReg = ReadBuffer[];
         if((StatusReg & FLASH_SR_IS_READY_MASK) == ) {
             break;
         }
     }

     return XST_SUCCESS;
 }

 2.函数SpiFlashGetStatus先写入一个命令COMMAND_STATUSREG_READ，然后用XSpi_Transfer函数将命令传入spi芯片中。

    当传送过程完成后，退出循环返回XST_SUCCESS 成功的状态，若传送没有完成，则一直执行：while(TransferInProgress);

 /*****************************************************************************/
 /**
 *
 * This function reads the Status register of the Numonyx Flash.
 *
 * @param    SpiPtr is a pointer to the instance of the Spi device.
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        The status register content is stored at the second byte
 *        pointed by the ReadBuffer.
 *
 ******************************************************************************/
 int SpiFlashGetStatus(XSpi *SpiPtr)
 {
     int Status;

     /*
      * Prepare the Write Buffer.
      */
     WriteBuffer[BYTE1] = COMMAND_STATUSREG_READ;

     /*
      * Initiate the Transfer.
      */
     TransferInProgress = TRUE;
     Status = XSpi_Transfer(SpiPtr, WriteBuffer, ReadBuffer,
                         STATUS_READ_BYTES);
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Wait till the Transfer is complete and check if there are any errors
      * in the transaction..
      */
     while(TransferInProgress);
     if(ErrorCount != ) {
         ErrorCount = ;
         return XST_FAILURE;
     }

     return XST_SUCCESS;
 }

3. SpiFlashWriteEnable函数

首先检测spi flash 是否ready , 然后写入写使能命令：COMMAND_WRITE_ENABLE 到WriteBuffer中，最后通过XSPi_Transfer函数将命令发出。

 /*****************************************************************************/
 /**
 *
 * This function enables writes to the Numonyx Serial Flash memory.
 *
 * @param    SpiPtr is a pointer to the instance of the Spi device.
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        None
 *
 ******************************************************************************/
 int SpiFlashWriteEnable(XSpi *SpiPtr)
 {
     int Status;

     /*
      * Wait while the Flash is busy.
      */
     Status = SpiFlashWaitForFlashReady();
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Prepare the WriteBuffer.
      */
     WriteBuffer[BYTE1] = COMMAND_WRITE_ENABLE;

     /*
      * Initiate the Transfer.
      */
     TransferInProgress = TRUE;
     Status = XSpi_Transfer(SpiPtr, WriteBuffer, NULL,
                 WRITE_ENABLE_BYTES);
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Wait till the Transfer is complete and check if there are any errors
      * in the transaction..
      */
     while(TransferInProgress);
     if(ErrorCount != ) {
         ErrorCount = ;
         return XST_FAILURE;
     }

     return XST_SUCCESS;
 }

4.SpiFlashSectorErase函数，依旧是先检测spi flash 是否ready. 然后就是将要写的内容存入writebuffer中，主要命令和地址信息。

 /*****************************************************************************/
 /**
 *
 * This function erases the contents of the specified Sector in the Numonyx
 * Serial Flash device.
 *
 * @param    SpiPtr is a pointer to the instance of the Spi device.
 * @param    Addr is the address within a sector of the Buffer, which is to
 *        be erased.
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        The erased bytes will be read back as 0xFF.
 *
 ******************************************************************************/
 int SpiFlashSectorErase(XSpi *SpiPtr, u32 Addr)
 {
     int Status;

     /*
      * Wait while the Flash is busy.
      */
     Status = SpiFlashWaitForFlashReady();
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Prepare the WriteBuffer.
      */
     WriteBuffer[BYTE1] = COMMAND_SECTOR_ERASE;
     WriteBuffer[BYTE2] = (u8) (Addr >> );
     WriteBuffer[BYTE3] = (u8) (Addr >> );
     WriteBuffer[BYTE4] = (u8) (Addr);

     /*
      * Initiate the Transfer.
      */
     TransferInProgress = TRUE;
     Status = XSpi_Transfer(SpiPtr, WriteBuffer, NULL,
                     SECTOR_ERASE_BYTES);
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Wait till the Transfer is complete and check if there are any errors
      * in the transaction..
      */
     while(TransferInProgress);
     if(ErrorCount != ) {
         ErrorCount = ;
         return XST_FAILURE;
     }

     return XST_SUCCESS;
 }

5.SpiFlashWrite函数，依旧是检测是否ready,然后写入地址和命令，接下来就是用一个for循环 把将要写入的数据一个一个存入writeBuffer中，然后通过Xspi_Transfer函数

一起发送出去。

 /*****************************************************************************/
 /**
 *
 * This function writes the data to the specified locations in the Numonyx Serial
 * Flash memory.
 *
 * @param    SpiPtr is a pointer to the instance of the Spi device.
 * @param    Addr is the address in the Buffer, where to write the data.
 * @param    ByteCount is the number of bytes to be written.
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        None
 *
 ******************************************************************************/
 int SpiFlashWrite(XSpi *SpiPtr, u32 Addr, u32 ByteCount, u8 WriteCmd)
 {
     u32 Index;
     int Status;

     /*
      * Wait while the Flash is busy.
      */
     Status = SpiFlashWaitForFlashReady();
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Prepare the WriteBuffer.
      */
     WriteBuffer[BYTE1] = WriteCmd;
     WriteBuffer[BYTE2] = (u8) (Addr >> );
     WriteBuffer[BYTE3] = (u8) (Addr >> );
     WriteBuffer[BYTE4] = (u8) Addr;

     /*
      * Fill in the TEST data that is to be written into the Numonyx Serial
      * Flash device.
      */
     for(Index = ; Index < ByteCount + READ_WRITE_EXTRA_BYTES; Index++) {
         WriteBuffer[Index] = (u8)((Index - ) + TestByte);
     }

     /*
      * Initiate the Transfer.
      */
     TransferInProgress = TRUE;
     Status = XSpi_Transfer(SpiPtr, WriteBuffer, NULL,
                 (ByteCount + READ_WRITE_EXTRA_BYTES));
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Wait till the Transfer is complete and check if there are any errors
      * in the transaction.
      */
     while(TransferInProgress);
     if(ErrorCount != ) {
         ErrorCount = ;
         return XST_FAILURE;
     }

     return XST_SUCCESS;
 }

6.SpiFlashRead 函数，先检测spi flash 是否ready,然后将readcmd命令和读地址存入writeBuffer, 接下来就是先判断read函数接收的是那种命令，根据接收的命令来

处理ByteCount的值，最后就是用transfer函数将要写入的命令发给spi flash, 然后将读到的数据存入readbuffer中。

 /*****************************************************************************/
 /**
 *
 * This function reads the data from the Numonyx Serial Flash Memory
 *
 * @param    SpiPtr is a pointer to the instance of the Spi device.
 * @param    Addr is the starting address in the Flash Memory from which the
 *        data is to be read.
 * @param    ByteCount is the number of bytes to be read.
 *
 * @return    XST_SUCCESS if successful else XST_FAILURE.
 *
 * @note        None
 *
 ******************************************************************************/
 int SpiFlashRead(XSpi *SpiPtr, u32 Addr, u32 ByteCount, u8 ReadCmd)
 {
     int Status;

     /*
      * Wait while the Flash is busy.
      */
     Status = SpiFlashWaitForFlashReady();
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Prepare the WriteBuffer.
      */
     WriteBuffer[BYTE1] = ReadCmd;
     WriteBuffer[BYTE2] = (u8) (Addr >> );
     WriteBuffer[BYTE3] = (u8) (Addr >> );
     WriteBuffer[BYTE4] = (u8) Addr;

     if (ReadCmd == COMMAND_DUAL_READ) {
         ByteCount += DUAL_READ_DUMMY_BYTES;
     } else if (ReadCmd == COMMAND_DUAL_IO_READ) {
         ByteCount += DUAL_READ_DUMMY_BYTES;
     } else if (ReadCmd == COMMAND_QUAD_IO_READ) {
         ByteCount += QUAD_IO_READ_DUMMY_BYTES;
     } else if (ReadCmd==COMMAND_QUAD_READ) {
         ByteCount += QUAD_READ_DUMMY_BYTES;
     }

     /*
      * Initiate the Transfer.
      */
     TransferInProgress = TRUE;
     Status = XSpi_Transfer( SpiPtr, WriteBuffer, ReadBuffer,
                 (ByteCount + READ_WRITE_EXTRA_BYTES));
     if(Status != XST_SUCCESS) {
         return XST_FAILURE;
     }

     /*
      * Wait till the Transfer is complete and check if there are any errors
      * in the transaction.
      */
     while(TransferInProgress);
     if(ErrorCount != ) {
         ErrorCount = ;
         return XST_FAILURE;
     }

     return XST_SUCCESS;
 }