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/******************** (C) COPYRIGHT 2007 STMicroelectronics ********************

* File Name          : spi_flash.c

* Author             : MCD Application Team

* Date First Issued  : 02/05/2007

* Description        : This file provides a set of functions needed to manage the

*                      communication between SPI peripheral and SPI M25P64 FLASH.

********************************************************************************

* History:

* 04/02/2007: V0.2

* 02/05/2007: V0.1

********************************************************************************

* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS

* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.

* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,

* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE

* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING

* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.

*******************************************************************************/

/* Includes ------------------------------------------------------------------*/

#include "spi_flash.h"

/* Private typedef -----------------------------------------------------------*/

#define SPI_FLASH_PageSize 256

#define WRITE      0x02  /* Write to Memory instruction */

#define WRSR       0x01  /* Write Status Register instruction */ 

#define WREN       0x06  /* Write enable instruction */

#define READ       0x03  /* Read from Memory instruction */

#define RDSR       0x05  /* Read Status Register instruction  */

#define RDID       0x9F  /* Read identification */

#define SE         0xD8  /* Sector Erase instruction */

#define BE         0xC7  /* Bulk Erase instruction */

#define WIP_Flag   0x01  /* Write In Progress (WIP) flag */

#define Dummy_Byte 0xA5

/* Private define ------------------------------------------------------------*/

/* Private macro -------------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/

/* Private function prototypes -----------------------------------------------*/

/* Private functions ---------------------------------------------------------*/

/*******************************************************************************

* Function Name  : SPI_FLASH_Init

* Description    : Initializes the peripherals used by the SPI FLASH driver.

* Input          : None

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_Init(void)

{

  SPI_InitTypeDef  SPI_InitStructure;

  GPIO_InitTypeDef GPIO_InitStructure;

  /* Enable SPI1 and GPIOA clocks */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA, ENABLE);

  /* Configure SPI1 pins: NSS, SCK, MISO and MOSI */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure PA.4 as Output push-pull, used as Flash Chip select */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

  /* SPI1 configuration */

  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;

  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;

  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;

  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;

  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;

  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;

  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;

  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;

  SPI_InitStructure.SPI_CRCPolynomial = 7;

  SPI_Init(SPI1, &SPI_InitStructure);

  /* Enable SPI1  */

  SPI_Cmd(SPI1, ENABLE);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_SectorErase

* Description    : Erases the specified FLASH sector.

* Input          : SectorAddr: address of the sector to erase.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_SectorErase(u32 SectorAddr)

{

  /* Send write enable instruction */

  SPI_FLASH_WriteEnable();

  /* Sector Erase */

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send Sector Erase instruction  */

  SPI_FLASH_SendByte(SE);

  /* Send SectorAddr high nibble address byte */

  SPI_FLASH_SendByte((SectorAddr & 0xFF0000) >> 16);

  /* Send SectorAddr medium nibble address byte */

  SPI_FLASH_SendByte((SectorAddr & 0xFF00) >> 8);

  /* Send SectorAddr low nibble address byte */

  SPI_FLASH_SendByte(SectorAddr & 0xFF);

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

  /* Wait the end of Flash writing */

  SPI_FLASH_WaitForWriteEnd();

}

/*******************************************************************************

* Function Name  : SPI_FLASH_BulkErase

* Description    : Erases the entire FLASH.

* Input          : None

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_BulkErase(void)

{

  /* Send write enable instruction */

  SPI_FLASH_WriteEnable();

  /* Bulk Erase */

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send Bulk Erase instruction  */

  SPI_FLASH_SendByte(BE);

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

  /* Wait the end of Flash writing */

  SPI_FLASH_WaitForWriteEnd();

}

/*******************************************************************************

* Function Name  : SPI_FLASH_PageWrite

* Description    : Writes more than one byte to the FLASH with a single WRITE

*                  cycle(Page WRITE sequence). The number of byte can't exceed

*                  the FLASH page size.

* Input          : - pBuffer : pointer to the buffer  containing the data to be

*                    written to the FLASH.

*                  - WriteAddr : FLASH's internal address to write to.

*                  - NumByteToWrite : number of bytes to write to the FLASH,

*                    must be equal or less than "SPI_FLASH_PageSize" value.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_PageWrite(u8* pBuffer, u32 WriteAddr, u16 NumByteToWrite)

{

  /* Enable the write access to the FLASH */

  SPI_FLASH_WriteEnable();

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "Write to Memory " instruction */

  SPI_FLASH_SendByte(WRITE);

  /* Send WriteAddr high nibble address byte to write to */

  SPI_FLASH_SendByte((WriteAddr & 0xFF0000) >> 16);

  /* Send WriteAddr medium nibble address byte to write to */

  SPI_FLASH_SendByte((WriteAddr & 0xFF00) >> 8);

  /* Send WriteAddr low nibble address byte to write to */

  SPI_FLASH_SendByte(WriteAddr & 0xFF);

  /* while there is data to be written on the FLASH */

  while(NumByteToWrite--)

  {

    /* Send the current byte */

    SPI_FLASH_SendByte(*pBuffer);

    /* Point on the next byte to be written */

    pBuffer++;

  }

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

  /* Wait the end of Flash writing */

  SPI_FLASH_WaitForWriteEnd();

}

/*******************************************************************************

* Function Name  : SPI_FLASH_BufferWrite

* Description    : Writes block of data to the FLASH. In this function, the

*                  number of WRITE cycles are reduced, using Page WRITE sequence.

* Input          : - pBuffer : pointer to the buffer  containing the data to be

*                    written to the FLASH.

*                  - WriteAddr : FLASH's internal address to write to.

*                  - NumByteToWrite : number of bytes to write to the FLASH.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_BufferWrite(u8* pBuffer, u32 WriteAddr, u16 NumByteToWrite)

{

  u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0, temp = 0;

  Addr = WriteAddr % SPI_FLASH_PageSize;

  count = SPI_FLASH_PageSize - Addr;

  NumOfPage =  NumByteToWrite / SPI_FLASH_PageSize;

  NumOfSingle = NumByteToWrite % SPI_FLASH_PageSize;

  if(Addr == 0) /* WriteAddr is SPI_FLASH_PageSize aligned  */

  {

    if(NumOfPage == 0) /* NumByteToWrite < SPI_FLASH_PageSize */

    {

      SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumByteToWrite);

    }

    else /* NumByteToWrite > SPI_FLASH_PageSize */

    {

      while(NumOfPage--)

      {

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, SPI_FLASH_PageSize);

        WriteAddr +=  SPI_FLASH_PageSize;

        pBuffer += SPI_FLASH_PageSize;

      }

      SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumOfSingle);

   }

  }

  else /* WriteAddr is not SPI_FLASH_PageSize aligned  */

  {

    if(NumOfPage== 0) /* NumByteToWrite < SPI_FLASH_PageSize */

    {

      if(NumOfSingle > count) /* (NumByteToWrite + WriteAddr) > SPI_FLASH_PageSize */

      {

        temp = NumOfSingle - count;

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, count);

        WriteAddr +=  count;

        pBuffer += count;

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, temp);

      }

      else

      {

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumByteToWrite);

      }

    }

    else /* NumByteToWrite > SPI_FLASH_PageSize */

    {

      NumByteToWrite -= count;

      NumOfPage =  NumByteToWrite / SPI_FLASH_PageSize;

      NumOfSingle = NumByteToWrite % SPI_FLASH_PageSize;

      SPI_FLASH_PageWrite(pBuffer, WriteAddr, count);

      WriteAddr +=  count;

      pBuffer += count;

      while(NumOfPage--)

      {

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, SPI_FLASH_PageSize);

        WriteAddr +=  SPI_FLASH_PageSize;

        pBuffer += SPI_FLASH_PageSize;

      }

      if(NumOfSingle != 0)

      {

        SPI_FLASH_PageWrite(pBuffer, WriteAddr, NumOfSingle);

      }

    }

  }

}

/*******************************************************************************

* Function Name  : SPI_FLASH_BufferRead

* Description    : Reads a block of data from the FLASH.

* Input          : - pBuffer : pointer to the buffer that receives the data read

*                    from the FLASH.

*                  - ReadAddr : FLASH's internal address to read from.

*                  - NumByteToRead : number of bytes to read from the FLASH.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_BufferRead(u8* pBuffer, u32 ReadAddr, u16 NumByteToRead)

{

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "Read from Memory " instruction */

  SPI_FLASH_SendByte(READ);

  /* Send ReadAddr high nibble address byte to read from */

  SPI_FLASH_SendByte((ReadAddr & 0xFF0000) >> 16);

  /* Send ReadAddr medium nibble address byte to read from */

  SPI_FLASH_SendByte((ReadAddr& 0xFF00) >> 8);

  /* Send ReadAddr low nibble address byte to read from */

  SPI_FLASH_SendByte(ReadAddr & 0xFF);

  while(NumByteToRead--) /* while there is data to be read */

  {

    /* Read a byte from the FLASH */

    *pBuffer = SPI_FLASH_SendByte(Dummy_Byte);

    /* Point to the next location where the byte read will be saved */

    pBuffer++;

  }

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_ReadID

* Description    : Reads FLASH identification.

* Input          : None

* Output         : None

* Return         : FLASH identification

*******************************************************************************/

u32 SPI_FLASH_ReadID(void)

{

  u32 Temp = 0, Temp0 = 0, Temp1 = 0, Temp2 = 0;

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "RDID " instruction */

  SPI_FLASH_SendByte(0x9F);

  /* Read a byte from the FLASH */

  Temp0 = SPI_FLASH_SendByte(Dummy_Byte);

  /* Read a byte from the FLASH */

  Temp1 = SPI_FLASH_SendByte(Dummy_Byte);

  /* Read a byte from the FLASH */

  Temp2 = SPI_FLASH_SendByte(Dummy_Byte);

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

  Temp = (Temp0 << 16) | (Temp1 << 8) | Temp2;

  return Temp;

}

/*******************************************************************************

* Function Name  : SPI_FLASH_StartReadSequence

* Description    : Initiates a read data byte (READ) sequence from the Flash.

*                  This is done by driving the /CS line low to select the device,

*                  then the READ instruction is transmitted followed by 3 bytes

*                  address. This function exit and keep the /CS line low, so the

*                  Flash still being selected. With this technique the whole

*                  content of the Flash is read with a single READ instruction.

* Input          : - ReadAddr : FLASH's internal address to read from.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_StartReadSequence(u32 ReadAddr)

{

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "Read from Memory " instruction */

  SPI_FLASH_SendByte(READ);

/* Send the 24-bit address of the address to read from -----------------------*/

  /* Send ReadAddr high nibble address byte */

  SPI_FLASH_SendByte((ReadAddr & 0xFF0000) >> 16);

  /* Send ReadAddr medium nibble address byte */

  SPI_FLASH_SendByte((ReadAddr& 0xFF00) >> 8);

  /* Send ReadAddr low nibble address byte */

  SPI_FLASH_SendByte(ReadAddr & 0xFF);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_ReadByte

* Description    : Reads a byte from the SPI Flash.

*                  This function must be used only if the Start_Read_Sequence

*                  function has been previously called.

* Input          : None

* Output         : None

* Return         : Byte Read from the SPI Flash.

*******************************************************************************/

u8 SPI_FLASH_ReadByte(void)

{

  return (SPI_FLASH_SendByte(Dummy_Byte));

}

/*******************************************************************************

* Function Name  : SPI_FLASH_ChipSelect

* Description    : Selects or deselects the FLASH.

* Input          : State : level to be applied on the FLASH's ChipSelect pin.

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_ChipSelect(u8 State)

{

  /* Set High or low the chip select line on PA.4 pin */

  GPIO_WriteBit(GPIOA, GPIO_Pin_4, (BitAction)State);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_SendByte

* Description    : Sends a byte through the SPI interface and return the byte

*                  received from the SPI bus.

* Input          : byte : byte to send.

* Output         : None

* Return         : The value of the received byte.

*******************************************************************************/

u8 SPI_FLASH_SendByte(u8 byte)

{

  /* Loop while DR register in not emplty */

  while(SPI_GetFlagStatus(SPI1, SPI_FLAG_TXE) == RESET);

  /* Send byte through the SPI1 peripheral */

  SPI_SendData(SPI1, byte);

  /* Wait to receive a byte */

  while(SPI_GetFlagStatus(SPI1, SPI_FLAG_RXNE) == RESET);

  /* Return the byte read from the SPI bus */

  return SPI_ReceiveData(SPI1);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_SendHalfWord

* Description    : Sends a Half Word through the SPI interface and return the

*                  Half Word received from the SPI bus.

* Input          : Half Word : Half Word to send.

* Output         : None

* Return         : The value of the received Half Word.

*******************************************************************************/

u16 SPI_FLASH_SendHalfWord(u16 HalfWord)

{

  /* Loop while DR register in not emplty */

  while(SPI_GetFlagStatus(SPI1, SPI_FLAG_TXE) == RESET);

  /* Send Half Word through the SPI1 peripheral */

  SPI_SendData(SPI1, HalfWord);

  /* Wait to receive a Half Word */

  while(SPI_GetFlagStatus(SPI1, SPI_FLAG_RXNE) == RESET);

  /* Return the Half Word read from the SPI bus */

  return SPI_ReceiveData(SPI1);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_WriteEnable

* Description    : Enables the write access to the FLASH.

* Input          : None

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_WriteEnable(void)

{

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "Write Enable" instruction */

  SPI_FLASH_SendByte(WREN);

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

}

/*******************************************************************************

* Function Name  : SPI_FLASH_WaitForWriteEnd

* Description    : Polls the status of the Write In Progress (WIP) flag in the

*                  FLASH's status  register  and  loop  until write  opertaion

*                  has completed.

* Input          : None

* Output         : None

* Return         : None

*******************************************************************************/

void SPI_FLASH_WaitForWriteEnd(void)

{

  u8 FLASH_Status = 0;

  /* Select the FLASH: Chip Select low */

  SPI_FLASH_ChipSelect(Low);

  /* Send "Read Status Register" instruction */

  SPI_FLASH_SendByte(RDSR);

  /* Loop as long as the memory is busy with a write cycle */

  do

  {

    /* Send a dummy byte to generate the clock needed by the FLASH

    and put the value of the status register in FLASH_Status variable */

    FLASH_Status = SPI_FLASH_SendByte(Dummy_Byte);

  } while((FLASH_Status & WIP_Flag) == SET); /* Write in progress */

  /* Deselect the FLASH: Chip Select high */

  SPI_FLASH_ChipSelect(High);

}

/******************* (C) COPYRIGHT 2007 STMicroelectronics *****END OF FILE****/