AMiRo-OS

/**

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

  * @file    stm32f4xx_spi.c

  * @author  MCD Application Team

  * @version V1.1.0

  * @date    11-January-2013

  * @brief   This file provides firmware functions to manage the following 

  *          functionalities of the Serial peripheral interface (SPI):

  *           + Initialization and Configuration

  *           + Data transfers functions

  *           + Hardware CRC Calculation

  *           + DMA transfers management

  *           + Interrupts and flags management 

  *           

@verbatim

 ===================================================================

                  ##### How to use this driver #####

 ===================================================================

 [..]

   (#) Enable peripheral clock using the following functions 

       RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE) for SPI1

       RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE) for SPI2

       RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE) for SPI3

       RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE) for SPI4

       RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE) for SPI5

       RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE) for SPI6.

   (#) Enable SCK, MOSI, MISO and NSS GPIO clocks using RCC_AHB1PeriphClockCmd()

       function. In I2S mode, if an external clock source is used then the I2S 

       CKIN pin GPIO clock should also be enabled.

   (#) Peripherals alternate function: 

       (++) Connect the pin to the desired peripherals' Alternate Function (AF) 

            using GPIO_PinAFConfig() function

       (++) Configure the desired pin in alternate function by: 

            GPIO_InitStruct->GPIO_Mode = GPIO_Mode_AF

       (++) Select the type, pull-up/pull-down and output speed via GPIO_PuPd, 

            GPIO_OType and GPIO_Speed members

       (++) Call GPIO_Init() function In I2S mode, if an external clock source is 

            used then the I2S CKIN pin should be also configured in Alternate 

            function Push-pull pull-up mode. 

   (#) Program the Polarity, Phase, First Data, Baud Rate Prescaler, Slave 

       Management, Peripheral Mode and CRC Polynomial values using the SPI_Init()

       function.

       In I2S mode, program the Mode, Standard, Data Format, MCLK Output, Audio 

       frequency and Polarity using I2S_Init() function. For I2S mode, make sure 

       that either:

       (++) I2S PLL is configured using the functions 

            RCC_I2SCLKConfig(RCC_I2S2CLKSource_PLLI2S), RCC_PLLI2SCmd(ENABLE) and 

            RCC_GetFlagStatus(RCC_FLAG_PLLI2SRDY); or 

       (++) External clock source is configured using the function 

            RCC_I2SCLKConfig(RCC_I2S2CLKSource_Ext) and after setting correctly 

            the define constant I2S_EXTERNAL_CLOCK_VAL in the stm32f4xx_conf.h file. 

   (#) Enable the NVIC and the corresponding interrupt using the function 

       SPI_ITConfig() if you need to use interrupt mode. 

   (#) When using the DMA mode 

       (++) Configure the DMA using DMA_Init() function

       (++) Active the needed channel Request using SPI_I2S_DMACmd() function

   (#) Enable the SPI using the SPI_Cmd() function or enable the I2S using

       I2S_Cmd().

   (#) Enable the DMA using the DMA_Cmd() function when using DMA mode. 

   (#) Optionally, you can enable/configure the following parameters without

       re-initialization (i.e there is no need to call again SPI_Init() function):

       (++) When bidirectional mode (SPI_Direction_1Line_Rx or SPI_Direction_1Line_Tx)

            is programmed as Data direction parameter using the SPI_Init() function

            it can be possible to switch between SPI_Direction_Tx or SPI_Direction_Rx

            using the SPI_BiDirectionalLineConfig() function.

       (++) When SPI_NSS_Soft is selected as Slave Select Management parameter 

            using the SPI_Init() function it can be possible to manage the 

            NSS internal signal using the SPI_NSSInternalSoftwareConfig() function.

       (++) Reconfigure the data size using the SPI_DataSizeConfig() function  

       (++) Enable or disable the SS output using the SPI_SSOutputCmd() function  

    (#) To use the CRC Hardware calculation feature refer to the Peripheral 

        CRC hardware Calculation subsection.

 [..] It is possible to use SPI in I2S full duplex mode, in this case, each SPI 

      peripheral is able to manage sending and receiving data simultaneously

      using two data lines. Each SPI peripheral has an extended block called I2Sxext

      (ie. I2S2ext for SPI2 and I2S3ext for SPI3).

      The extension block is not a full SPI IP, it is used only as I2S slave to

      implement full duplex mode. The extension block uses the same clock sources

      as its master.          

      To configure I2S full duplex you have to:

      (#) Configure SPIx in I2S mode (I2S_Init() function) as described above. 

      (#) Call the I2S_FullDuplexConfig() function using the same strucutre passed to  

          I2S_Init() function.

      (#) Call I2S_Cmd() for SPIx then for its extended block.

      (#) To configure interrupts or DMA requests and to get/clear flag status, 

          use I2Sxext instance for the extension block.

 [..] Functions that can be called with I2Sxext instances are: I2S_Cmd(), 

      I2S_FullDuplexConfig(), SPI_I2S_ReceiveData(), SPI_I2S_SendData(), 

      SPI_I2S_DMACmd(), SPI_I2S_ITConfig(), SPI_I2S_GetFlagStatus(), 

      SPI_I2S_ClearFlag(), SPI_I2S_GetITStatus() and SPI_I2S_ClearITPendingBit().

      Example: To use SPI3 in Full duplex mode (SPI3 is Master Tx, I2S3ext is Slave Rx):

      RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);   

      I2S_StructInit(&I2SInitStruct);

      I2SInitStruct.Mode = I2S_Mode_MasterTx;     

      I2S_Init(SPI3, &I2SInitStruct);

      I2S_FullDuplexConfig(SPI3ext, &I2SInitStruct)

      I2S_Cmd(SPI3, ENABLE);

      I2S_Cmd(SPI3ext, ENABLE);

      ...

      while (SPI_I2S_GetFlagStatus(SPI2, SPI_FLAG_TXE) == RESET)

      {}

      SPI_I2S_SendData(SPI3, txdata[i]);

      ...  

      while (SPI_I2S_GetFlagStatus(I2S3ext, SPI_FLAG_RXNE) == RESET)

      {}

      rxdata[i] = SPI_I2S_ReceiveData(I2S3ext);

      ...          

 [..]       

   (@) In I2S mode: if an external clock is used as source clock for the I2S,  

       then the define I2S_EXTERNAL_CLOCK_VAL in file stm32f4xx_conf.h should 

       be enabled and set to the value of the source clock frequency (in Hz).

   (@) In SPI mode: To use the SPI TI mode, call the function SPI_TIModeCmd() 

       just after calling the function SPI_Init().

@endverbatim  

  *                                  

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

  * @attention

  *

  * <h2><center>&copy; COPYRIGHT 2013 STMicroelectronics</center></h2>

  *

  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");

  * You may not use this file except in compliance with the License.

  * You may obtain a copy of the License at:

  *

  *        http://www.st.com/software_license_agreement_liberty_v2

  *

  * Unless required by applicable law or agreed to in writing, software 

  * distributed under the License is distributed on an "AS IS" BASIS, 

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  *

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

  */ 

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

#include "stm32f4xx_spi.h"

#include "stm32f4xx_rcc.h"

/** @addtogroup STM32F4xx_StdPeriph_Driver

  * @{

  */

/** @defgroup SPI 

  * @brief SPI driver modules

  * @{

  */ 

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

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

/* SPI registers Masks */

#define CR1_CLEAR_MASK            ((uint16_t)0x3040)

#define I2SCFGR_CLEAR_MASK        ((uint16_t)0xF040)

/* RCC PLLs masks */

#define PLLCFGR_PPLR_MASK         ((uint32_t)0x70000000)

#define PLLCFGR_PPLN_MASK         ((uint32_t)0x00007FC0)

#define SPI_CR2_FRF               ((uint16_t)0x0010)

#define SPI_SR_TIFRFE             ((uint16_t)0x0100)

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

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

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

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

/** @defgroup SPI_Private_Functions

  * @{

  */

/** @defgroup SPI_Group1 Initialization and Configuration functions

 *  @brief   Initialization and Configuration functions 

 *

@verbatim   

 ===============================================================================

             ##### Initialization and Configuration functions ##### 

 ===============================================================================  

 [..] This section provides a set of functions allowing to initialize the SPI 

      Direction, SPI Mode, SPI Data Size, SPI Polarity, SPI Phase, SPI NSS 

      Management, SPI Baud Rate Prescaler, SPI First Bit and SPI CRC Polynomial.

 [..] The SPI_Init() function follows the SPI configuration procedures for Master 

      mode and Slave mode (details for these procedures are available in reference 

      manual (RM0090)).

@endverbatim

  * @{

  */

/**

  * @brief  De-initialize the SPIx peripheral registers to their default reset values.

  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2, 3, 4, 5 or 6 

  *         in SPI mode or 2 or 3 in I2S mode.   

  *         

  * @note   The extended I2S blocks (ie. I2S2ext and I2S3ext blocks) are de-initialized

  *         when the relative I2S peripheral is de-initialized (the extended block's clock

  *         is managed by the I2S peripheral clock).

  *             

  * @retval None

  */

void SPI_I2S_DeInit(SPI_TypeDef* SPIx)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  if (SPIx == SPI1)

  {

    /* Enable SPI1 reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI1, ENABLE);

    /* Release SPI1 from reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI1, DISABLE);

  }

  else if (SPIx == SPI2)

  {

    /* Enable SPI2 reset state */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI2, ENABLE);

    /* Release SPI2 from reset state */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI2, DISABLE);

  }

  else if (SPIx == SPI3)

  {

    /* Enable SPI3 reset state */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE);

    /* Release SPI3 from reset state */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, DISABLE);

  }

  else if (SPIx == SPI4)

  {

    /* Enable SPI4 reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI4, ENABLE);

    /* Release SPI4 from reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI4, DISABLE);

  }

  else if (SPIx == SPI5)

  {

    /* Enable SPI5 reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI5, ENABLE);

    /* Release SPI5 from reset state */

    RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI5, DISABLE);

  }

  else 

  {

    if (SPIx == SPI6)

    {

      /* Enable SPI6 reset state */

      RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI6, ENABLE);

      /* Release SPI6 from reset state */

      RCC_APB2PeriphResetCmd(RCC_APB2Periph_SPI6, DISABLE);

    }

  }

}

/**

  * @brief  Initializes the SPIx peripheral according to the specified 

  *         parameters in the SPI_InitStruct.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  SPI_InitStruct: pointer to a SPI_InitTypeDef structure that

  *         contains the configuration information for the specified SPI peripheral.

  * @retval None

  */

void SPI_Init(SPI_TypeDef* SPIx, SPI_InitTypeDef* SPI_InitStruct)

{

  uint16_t tmpreg = 0;

  /* check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  /* Check the SPI parameters */

  assert_param(IS_SPI_DIRECTION_MODE(SPI_InitStruct->SPI_Direction));

  assert_param(IS_SPI_MODE(SPI_InitStruct->SPI_Mode));

  assert_param(IS_SPI_DATASIZE(SPI_InitStruct->SPI_DataSize));

  assert_param(IS_SPI_CPOL(SPI_InitStruct->SPI_CPOL));

  assert_param(IS_SPI_CPHA(SPI_InitStruct->SPI_CPHA));

  assert_param(IS_SPI_NSS(SPI_InitStruct->SPI_NSS));

  assert_param(IS_SPI_BAUDRATE_PRESCALER(SPI_InitStruct->SPI_BaudRatePrescaler));

  assert_param(IS_SPI_FIRST_BIT(SPI_InitStruct->SPI_FirstBit));

  assert_param(IS_SPI_CRC_POLYNOMIAL(SPI_InitStruct->SPI_CRCPolynomial));

/*---------------------------- SPIx CR1 Configuration ------------------------*/

  /* Get the SPIx CR1 value */

  tmpreg = SPIx->CR1;

  /* Clear BIDIMode, BIDIOE, RxONLY, SSM, SSI, LSBFirst, BR, MSTR, CPOL and CPHA bits */

  tmpreg &= CR1_CLEAR_MASK;

  /* Configure SPIx: direction, NSS management, first transmitted bit, BaudRate prescaler

     master/salve mode, CPOL and CPHA */

  /* Set BIDImode, BIDIOE and RxONLY bits according to SPI_Direction value */

  /* Set SSM, SSI and MSTR bits according to SPI_Mode and SPI_NSS values */

  /* Set LSBFirst bit according to SPI_FirstBit value */

  /* Set BR bits according to SPI_BaudRatePrescaler value */

  /* Set CPOL bit according to SPI_CPOL value */

  /* Set CPHA bit according to SPI_CPHA value */

  tmpreg |= (uint16_t)((uint32_t)SPI_InitStruct->SPI_Direction | SPI_InitStruct->SPI_Mode |

                  SPI_InitStruct->SPI_DataSize | SPI_InitStruct->SPI_CPOL |  

                  SPI_InitStruct->SPI_CPHA | SPI_InitStruct->SPI_NSS |  

                  SPI_InitStruct->SPI_BaudRatePrescaler | SPI_InitStruct->SPI_FirstBit);

  /* Write to SPIx CR1 */

  SPIx->CR1 = tmpreg;

  /* Activate the SPI mode (Reset I2SMOD bit in I2SCFGR register) */

  SPIx->I2SCFGR &= (uint16_t)~((uint16_t)SPI_I2SCFGR_I2SMOD);

/*---------------------------- SPIx CRCPOLY Configuration --------------------*/

  /* Write to SPIx CRCPOLY */

  SPIx->CRCPR = SPI_InitStruct->SPI_CRCPolynomial;

}

/**

  * @brief  Initializes the SPIx peripheral according to the specified 

  *         parameters in the I2S_InitStruct.

  * @param  SPIx: where x can be  2 or 3 to select the SPI peripheral (configured in I2S mode).

  * @param  I2S_InitStruct: pointer to an I2S_InitTypeDef structure that

  *         contains the configuration information for the specified SPI peripheral

  *         configured in I2S mode.

  *           

  * @note   The function calculates the optimal prescaler needed to obtain the most 

  *         accurate audio frequency (depending on the I2S clock source, the PLL values 

  *         and the product configuration). But in case the prescaler value is greater 

  *         than 511, the default value (0x02) will be configured instead.    

  * 

  * @note   if an external clock is used as source clock for the I2S, then the define

  *         I2S_EXTERNAL_CLOCK_VAL in file stm32f4xx_conf.h should be enabled and set

  *         to the value of the the source clock frequency (in Hz).

  *  

  * @retval None

  */

void I2S_Init(SPI_TypeDef* SPIx, I2S_InitTypeDef* I2S_InitStruct)

{

  uint16_t tmpreg = 0, i2sdiv = 2, i2sodd = 0, packetlength = 1;

  uint32_t tmp = 0, i2sclk = 0;

#ifndef I2S_EXTERNAL_CLOCK_VAL

  uint32_t pllm = 0, plln = 0, pllr = 0;

#endif /* I2S_EXTERNAL_CLOCK_VAL */

  /* Check the I2S parameters */

  assert_param(IS_SPI_23_PERIPH(SPIx));

  assert_param(IS_I2S_MODE(I2S_InitStruct->I2S_Mode));

  assert_param(IS_I2S_STANDARD(I2S_InitStruct->I2S_Standard));

  assert_param(IS_I2S_DATA_FORMAT(I2S_InitStruct->I2S_DataFormat));

  assert_param(IS_I2S_MCLK_OUTPUT(I2S_InitStruct->I2S_MCLKOutput));

  assert_param(IS_I2S_AUDIO_FREQ(I2S_InitStruct->I2S_AudioFreq));

  assert_param(IS_I2S_CPOL(I2S_InitStruct->I2S_CPOL));  

/*----------------------- SPIx I2SCFGR & I2SPR Configuration -----------------*/

  /* Clear I2SMOD, I2SE, I2SCFG, PCMSYNC, I2SSTD, CKPOL, DATLEN and CHLEN bits */

  SPIx->I2SCFGR &= I2SCFGR_CLEAR_MASK; 

  SPIx->I2SPR = 0x0002;

  /* Get the I2SCFGR register value */

  tmpreg = SPIx->I2SCFGR;

  /* If the default value has to be written, reinitialize i2sdiv and i2sodd*/

  if(I2S_InitStruct->I2S_AudioFreq == I2S_AudioFreq_Default)

  {

    i2sodd = (uint16_t)0;

    i2sdiv = (uint16_t)2;   

  }

  /* If the requested audio frequency is not the default, compute the prescaler */

  else

  {

    /* Check the frame length (For the Prescaler computing) *******************/

    if(I2S_InitStruct->I2S_DataFormat == I2S_DataFormat_16b)

    {

      /* Packet length is 16 bits */

      packetlength = 1;

    }

    else

    {

      /* Packet length is 32 bits */

      packetlength = 2;

    }

    /* Get I2S source Clock frequency  ****************************************/

    /* If an external I2S clock has to be used, this define should be set  

       in the project configuration or in the stm32f4xx_conf.h file */

  #ifdef I2S_EXTERNAL_CLOCK_VAL     

    /* Set external clock as I2S clock source */

    if ((RCC->CFGR & RCC_CFGR_I2SSRC) == 0)

    {

      RCC->CFGR |= (uint32_t)RCC_CFGR_I2SSRC;

    }

    /* Set the I2S clock to the external clock  value */

    i2sclk = I2S_EXTERNAL_CLOCK_VAL;

  #else /* There is no define for External I2S clock source */

    /* Set PLLI2S as I2S clock source */

    if ((RCC->CFGR & RCC_CFGR_I2SSRC) != 0)

    {

      RCC->CFGR &= ~(uint32_t)RCC_CFGR_I2SSRC;

    }    

    /* Get the PLLI2SN value */

    plln = (uint32_t)(((RCC->PLLI2SCFGR & RCC_PLLI2SCFGR_PLLI2SN) >> 6) & \

                      (RCC_PLLI2SCFGR_PLLI2SN >> 6));

    /* Get the PLLI2SR value */

    pllr = (uint32_t)(((RCC->PLLI2SCFGR & RCC_PLLI2SCFGR_PLLI2SR) >> 28) & \

                      (RCC_PLLI2SCFGR_PLLI2SR >> 28));

    /* Get the PLLM value */

    pllm = (uint32_t)(RCC->PLLCFGR & RCC_PLLCFGR_PLLM);      

    /* Get the I2S source clock value */

    i2sclk = (uint32_t)(((HSE_VALUE / pllm) * plln) / pllr);

  #endif /* I2S_EXTERNAL_CLOCK_VAL */

    /* Compute the Real divider depending on the MCLK output state, with a floating point */

    if(I2S_InitStruct->I2S_MCLKOutput == I2S_MCLKOutput_Enable)

    {

      /* MCLK output is enabled */

      tmp = (uint16_t)(((((i2sclk / 256) * 10) / I2S_InitStruct->I2S_AudioFreq)) + 5);

    }

    else

    {

      /* MCLK output is disabled */

      tmp = (uint16_t)(((((i2sclk / (32 * packetlength)) *10 ) / I2S_InitStruct->I2S_AudioFreq)) + 5);

    }

    /* Remove the flatting point */

    tmp = tmp / 10;  

    /* Check the parity of the divider */

    i2sodd = (uint16_t)(tmp & (uint16_t)0x0001);

    /* Compute the i2sdiv prescaler */

    i2sdiv = (uint16_t)((tmp - i2sodd) / 2);

    /* Get the Mask for the Odd bit (SPI_I2SPR[8]) register */

    i2sodd = (uint16_t) (i2sodd << 8);

  }

  /* Test if the divider is 1 or 0 or greater than 0xFF */

  if ((i2sdiv < 2) || (i2sdiv > 0xFF))

  {

    /* Set the default values */

    i2sdiv = 2;

    i2sodd = 0;

  }

  /* Write to SPIx I2SPR register the computed value */

  SPIx->I2SPR = (uint16_t)((uint16_t)i2sdiv | (uint16_t)(i2sodd | (uint16_t)I2S_InitStruct->I2S_MCLKOutput));

  /* Configure the I2S with the SPI_InitStruct values */

  tmpreg |= (uint16_t)((uint16_t)SPI_I2SCFGR_I2SMOD | (uint16_t)(I2S_InitStruct->I2S_Mode | \

                  (uint16_t)(I2S_InitStruct->I2S_Standard | (uint16_t)(I2S_InitStruct->I2S_DataFormat | \

                  (uint16_t)I2S_InitStruct->I2S_CPOL))));

  /* Write to SPIx I2SCFGR */  

  SPIx->I2SCFGR = tmpreg;

}

/**

  * @brief  Fills each SPI_InitStruct member with its default value.

  * @param  SPI_InitStruct: pointer to a SPI_InitTypeDef structure which will be initialized.

  * @retval None

  */

void SPI_StructInit(SPI_InitTypeDef* SPI_InitStruct)

{

/*--------------- Reset SPI init structure parameters values -----------------*/

  /* Initialize the SPI_Direction member */

  SPI_InitStruct->SPI_Direction = SPI_Direction_2Lines_FullDuplex;

  /* initialize the SPI_Mode member */

  SPI_InitStruct->SPI_Mode = SPI_Mode_Slave;

  /* initialize the SPI_DataSize member */

  SPI_InitStruct->SPI_DataSize = SPI_DataSize_8b;

  /* Initialize the SPI_CPOL member */

  SPI_InitStruct->SPI_CPOL = SPI_CPOL_Low;

  /* Initialize the SPI_CPHA member */

  SPI_InitStruct->SPI_CPHA = SPI_CPHA_1Edge;

  /* Initialize the SPI_NSS member */

  SPI_InitStruct->SPI_NSS = SPI_NSS_Hard;

  /* Initialize the SPI_BaudRatePrescaler member */

  SPI_InitStruct->SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;

  /* Initialize the SPI_FirstBit member */

  SPI_InitStruct->SPI_FirstBit = SPI_FirstBit_MSB;

  /* Initialize the SPI_CRCPolynomial member */

  SPI_InitStruct->SPI_CRCPolynomial = 7;

}

/**

  * @brief  Fills each I2S_InitStruct member with its default value.

  * @param  I2S_InitStruct: pointer to a I2S_InitTypeDef structure which will be initialized.

  * @retval None

  */

void I2S_StructInit(I2S_InitTypeDef* I2S_InitStruct)

{

/*--------------- Reset I2S init structure parameters values -----------------*/

  /* Initialize the I2S_Mode member */

  I2S_InitStruct->I2S_Mode = I2S_Mode_SlaveTx;

  /* Initialize the I2S_Standard member */

  I2S_InitStruct->I2S_Standard = I2S_Standard_Phillips;

  /* Initialize the I2S_DataFormat member */

  I2S_InitStruct->I2S_DataFormat = I2S_DataFormat_16b;

  /* Initialize the I2S_MCLKOutput member */

  I2S_InitStruct->I2S_MCLKOutput = I2S_MCLKOutput_Disable;

  /* Initialize the I2S_AudioFreq member */

  I2S_InitStruct->I2S_AudioFreq = I2S_AudioFreq_Default;

  /* Initialize the I2S_CPOL member */

  I2S_InitStruct->I2S_CPOL = I2S_CPOL_Low;

}

/**

  * @brief  Enables or disables the specified SPI peripheral.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  NewState: new state of the SPIx peripheral. 

  *          This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void SPI_Cmd(SPI_TypeDef* SPIx, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)

  {

    /* Enable the selected SPI peripheral */

    SPIx->CR1 |= SPI_CR1_SPE;

  }

  else

  {

    /* Disable the selected SPI peripheral */

    SPIx->CR1 &= (uint16_t)~((uint16_t)SPI_CR1_SPE);

  }

}

/**

  * @brief  Enables or disables the specified SPI peripheral (in I2S mode).

  * @param  SPIx: where x can be 2 or 3 to select the SPI peripheral (or I2Sxext 

  *         for full duplex mode).

  * @param  NewState: new state of the SPIx peripheral. 

  *         This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void I2S_Cmd(SPI_TypeDef* SPIx, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_23_PERIPH_EXT(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)

  {

    /* Enable the selected SPI peripheral (in I2S mode) */

    SPIx->I2SCFGR |= SPI_I2SCFGR_I2SE;

  }

  else

  {

    /* Disable the selected SPI peripheral in I2S mode */

    SPIx->I2SCFGR &= (uint16_t)~((uint16_t)SPI_I2SCFGR_I2SE);

  }

}

/**

  * @brief  Configures the data size for the selected SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  SPI_DataSize: specifies the SPI data size.

  *          This parameter can be one of the following values:

  *            @arg SPI_DataSize_16b: Set data frame format to 16bit

  *            @arg SPI_DataSize_8b: Set data frame format to 8bit

  * @retval None

  */

void SPI_DataSizeConfig(SPI_TypeDef* SPIx, uint16_t SPI_DataSize)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_SPI_DATASIZE(SPI_DataSize));

  /* Clear DFF bit */

  SPIx->CR1 &= (uint16_t)~SPI_DataSize_16b;

  /* Set new DFF bit value */

  SPIx->CR1 |= SPI_DataSize;

}

/**

  * @brief  Selects the data transfer direction in bidirectional mode for the specified SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  SPI_Direction: specifies the data transfer direction in bidirectional mode. 

  *          This parameter can be one of the following values:

  *            @arg SPI_Direction_Tx: Selects Tx transmission direction

  *            @arg SPI_Direction_Rx: Selects Rx receive direction

  * @retval None

  */

void SPI_BiDirectionalLineConfig(SPI_TypeDef* SPIx, uint16_t SPI_Direction)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_SPI_DIRECTION(SPI_Direction));

  if (SPI_Direction == SPI_Direction_Tx)

  {

    /* Set the Tx only mode */

    SPIx->CR1 |= SPI_Direction_Tx;

  }

  else

  {

    /* Set the Rx only mode */

    SPIx->CR1 &= SPI_Direction_Rx;

  }

}

/**

  * @brief  Configures internally by software the NSS pin for the selected SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  SPI_NSSInternalSoft: specifies the SPI NSS internal state.

  *          This parameter can be one of the following values:

  *            @arg SPI_NSSInternalSoft_Set: Set NSS pin internally

  *            @arg SPI_NSSInternalSoft_Reset: Reset NSS pin internally

  * @retval None

  */

void SPI_NSSInternalSoftwareConfig(SPI_TypeDef* SPIx, uint16_t SPI_NSSInternalSoft)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_SPI_NSS_INTERNAL(SPI_NSSInternalSoft));

  if (SPI_NSSInternalSoft != SPI_NSSInternalSoft_Reset)

  {

    /* Set NSS pin internally by software */

    SPIx->CR1 |= SPI_NSSInternalSoft_Set;

  }

  else

  {

    /* Reset NSS pin internally by software */

    SPIx->CR1 &= SPI_NSSInternalSoft_Reset;

  }

}

/**

  * @brief  Enables or disables the SS output for the selected SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  NewState: new state of the SPIx SS output. 

  *          This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void SPI_SSOutputCmd(SPI_TypeDef* SPIx, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)

  {

    /* Enable the selected SPI SS output */

    SPIx->CR2 |= (uint16_t)SPI_CR2_SSOE;

  }

  else

  {

    /* Disable the selected SPI SS output */

    SPIx->CR2 &= (uint16_t)~((uint16_t)SPI_CR2_SSOE);

  }

}

/**

  * @brief  Enables or disables the SPIx/I2Sx DMA interface.

  *   

  * @note   This function can be called only after the SPI_Init() function has 

  *         been called. 

  * @note   When TI mode is selected, the control bits SSM, SSI, CPOL and CPHA 

  *         are not taken into consideration and are configured by hardware

  *         respectively to the TI mode requirements.  

  * 

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 

  * @param  NewState: new state of the selected SPI TI communication mode.

  *          This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void SPI_TIModeCmd(SPI_TypeDef* SPIx, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)

  {

    /* Enable the TI mode for the selected SPI peripheral */

    SPIx->CR2 |= SPI_CR2_FRF;

  }

  else

  {

    /* Disable the TI mode for the selected SPI peripheral */

    SPIx->CR2 &= (uint16_t)~SPI_CR2_FRF;

  }

}

/**

  * @brief  Configures the full duplex mode for the I2Sx peripheral using its

  *         extension I2Sxext according to the specified parameters in the 

  *         I2S_InitStruct.

  * @param  I2Sxext: where x can be  2 or 3 to select the I2S peripheral extension block.

  * @param  I2S_InitStruct: pointer to an I2S_InitTypeDef structure that

  *         contains the configuration information for the specified I2S peripheral

  *         extension.

  * 

  * @note   The structure pointed by I2S_InitStruct parameter should be the same

  *         used for the master I2S peripheral. In this case, if the master is 

  *         configured as transmitter, the slave will be receiver and vice versa.

  *         Or you can force a different mode by modifying the field I2S_Mode to the

  *         value I2S_SlaveRx or I2S_SlaveTx indepedently of the master configuration.    

  *         

  * @note   The I2S full duplex extension can be configured in slave mode only.    

  *  

  * @retval None

  */

void I2S_FullDuplexConfig(SPI_TypeDef* I2Sxext, I2S_InitTypeDef* I2S_InitStruct)

{

  uint16_t tmpreg = 0, tmp = 0;

  /* Check the I2S parameters */

  assert_param(IS_I2S_EXT_PERIPH(I2Sxext));

  assert_param(IS_I2S_MODE(I2S_InitStruct->I2S_Mode));

  assert_param(IS_I2S_STANDARD(I2S_InitStruct->I2S_Standard));

  assert_param(IS_I2S_DATA_FORMAT(I2S_InitStruct->I2S_DataFormat));

  assert_param(IS_I2S_CPOL(I2S_InitStruct->I2S_CPOL));  

/*----------------------- SPIx I2SCFGR & I2SPR Configuration -----------------*/

  /* Clear I2SMOD, I2SE, I2SCFG, PCMSYNC, I2SSTD, CKPOL, DATLEN and CHLEN bits */

  I2Sxext->I2SCFGR &= I2SCFGR_CLEAR_MASK; 

  I2Sxext->I2SPR = 0x0002;

  /* Get the I2SCFGR register value */

  tmpreg = I2Sxext->I2SCFGR;

  /* Get the mode to be configured for the extended I2S */

  if ((I2S_InitStruct->I2S_Mode == I2S_Mode_MasterTx) || (I2S_InitStruct->I2S_Mode == I2S_Mode_SlaveTx))

  {

    tmp = I2S_Mode_SlaveRx;

  }

  else

  {

    if ((I2S_InitStruct->I2S_Mode == I2S_Mode_MasterRx) || (I2S_InitStruct->I2S_Mode == I2S_Mode_SlaveRx))

    {

      tmp = I2S_Mode_SlaveTx;

    }

  }

  /* Configure the I2S with the SPI_InitStruct values */

  tmpreg |= (uint16_t)((uint16_t)SPI_I2SCFGR_I2SMOD | (uint16_t)(tmp | \

                  (uint16_t)(I2S_InitStruct->I2S_Standard | (uint16_t)(I2S_InitStruct->I2S_DataFormat | \

                  (uint16_t)I2S_InitStruct->I2S_CPOL))));

  /* Write to SPIx I2SCFGR */  

  I2Sxext->I2SCFGR = tmpreg;

}

/**

  * @}

  */

/** @defgroup SPI_Group2 Data transfers functions

 *  @brief   Data transfers functions

 *

@verbatim   

 ===============================================================================

                      ##### Data transfers functions #####

 ===============================================================================  

 [..] This section provides a set of functions allowing to manage the SPI data 

      transfers. In reception, data are received and then stored into an internal 

      Rx buffer while. In transmission, data are first stored into an internal Tx 

      buffer before being transmitted.

 [..] The read access of the SPI_DR register can be done using the SPI_I2S_ReceiveData()

      function and returns the Rx buffered value. Whereas a write access to the SPI_DR 

      can be done using SPI_I2S_SendData() function and stores the written data into 

      Tx buffer.

@endverbatim

  * @{

  */

/**

  * @brief  Returns the most recent received data by the SPIx/I2Sx peripheral. 

  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2, 3, 4, 5 or 6 

  *         in SPI mode or 2 or 3 in I2S mode or I2Sxext for I2S full duplex mode. 

  * @retval The value of the received data.

  */

uint16_t SPI_I2S_ReceiveData(SPI_TypeDef* SPIx)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH_EXT(SPIx));

  /* Return the data in the DR register */

  return SPIx->DR;

}

/**

  * @brief  Transmits a Data through the SPIx/I2Sx peripheral.

  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2, 3, 4, 5 or 6 

  *         in SPI mode or 2 or 3 in I2S mode or I2Sxext for I2S full duplex mode.     

  * @param  Data: Data to be transmitted.

  * @retval None

  */

void SPI_I2S_SendData(SPI_TypeDef* SPIx, uint16_t Data)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH_EXT(SPIx));

  /* Write in the DR register the data to be sent */

  SPIx->DR = Data;

}

/**

  * @}

  */

/** @defgroup SPI_Group3 Hardware CRC Calculation functions

 *  @brief   Hardware CRC Calculation functions

 *

@verbatim   

 ===============================================================================

                 ##### Hardware CRC Calculation functions #####

 ===============================================================================  

 [..] This section provides a set of functions allowing to manage the SPI CRC hardware 

      calculation

 [..] SPI communication using CRC is possible through the following procedure:

   (#) Program the Data direction, Polarity, Phase, First Data, Baud Rate Prescaler, 

       Slave Management, Peripheral Mode and CRC Polynomial values using the SPI_Init()

       function.

   (#) Enable the CRC calculation using the SPI_CalculateCRC() function.

   (#) Enable the SPI using the SPI_Cmd() function

   (#) Before writing the last data to the TX buffer, set the CRCNext bit using the 

       SPI_TransmitCRC() function to indicate that after transmission of the last 

       data, the CRC should be transmitted.

   (#) After transmitting the last data, the SPI transmits the CRC. The SPI_CR1_CRCNEXT

        bit is reset. The CRC is also received and compared against the SPI_RXCRCR 

        value. 

        If the value does not match, the SPI_FLAG_CRCERR flag is set and an interrupt

        can be generated when the SPI_I2S_IT_ERR interrupt is enabled.

 [..]

   (@) It is advised not to read the calculated CRC values during the communication.

   (@) When the SPI is in slave mode, be careful to enable CRC calculation only 

       when the clock is stable, that is, when the clock is in the steady state. 

       If not, a wrong CRC calculation may be done. In fact, the CRC is sensitive 

       to the SCK slave input clock as soon as CRCEN is set, and this, whatever 

       the value of the SPE bit.

   (@) With high bitrate frequencies, be careful when transmitting the CRC.

       As the number of used CPU cycles has to be as low as possible in the CRC 

       transfer phase, it is forbidden to call software functions in the CRC 

       transmission sequence to avoid errors in the last data and CRC reception. 

       In fact, CRCNEXT bit has to be written before the end of the transmission/reception 

       of the last data.

   (@) For high bit rate frequencies, it is advised to use the DMA mode to avoid the

       degradation of the SPI speed performance due to CPU accesses impacting the 

       SPI bandwidth.

   (@) When the STM32F4xx is configured as slave and the NSS hardware mode is 

       used, the NSS pin needs to be kept low between the data phase and the CRC 

       phase.

   (@) When the SPI is configured in slave mode with the CRC feature enabled, CRC

       calculation takes place even if a high level is applied on the NSS pin. 

       This may happen for example in case of a multi-slave environment where the 

       communication master addresses slaves alternately.

   (@) Between a slave de-selection (high level on NSS) and a new slave selection 

       (low level on NSS), the CRC value should be cleared on both master and slave

       sides in order to resynchronize the master and slave for their respective 

       CRC calculation.

   (@) To clear the CRC, follow the procedure below:

       (#@) Disable SPI using the SPI_Cmd() function

       (#@) Disable the CRC calculation using the SPI_CalculateCRC() function.

       (#@) Enable the CRC calculation using the SPI_CalculateCRC() function.

       (#@) Enable SPI using the SPI_Cmd() function.

@endverbatim

  * @{

  */

/**

  * @brief  Enables or disables the CRC value calculation of the transferred bytes.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  NewState: new state of the SPIx CRC value calculation.

  *          This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void SPI_CalculateCRC(SPI_TypeDef* SPIx, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)

  {

    /* Enable the selected SPI CRC calculation */

    SPIx->CR1 |= SPI_CR1_CRCEN;

  }

  else

  {

    /* Disable the selected SPI CRC calculation */

    SPIx->CR1 &= (uint16_t)~((uint16_t)SPI_CR1_CRCEN);

  }

}

/**

  * @brief  Transmit the SPIx CRC value.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @retval None

  */

void SPI_TransmitCRC(SPI_TypeDef* SPIx)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  /* Enable the selected SPI CRC transmission */

  SPIx->CR1 |= SPI_CR1_CRCNEXT;

}

/**

  * @brief  Returns the transmit or the receive CRC register value for the specified SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @param  SPI_CRC: specifies the CRC register to be read.

  *          This parameter can be one of the following values:

  *            @arg SPI_CRC_Tx: Selects Tx CRC register

  *            @arg SPI_CRC_Rx: Selects Rx CRC register

  * @retval The selected CRC register value..

  */

uint16_t SPI_GetCRC(SPI_TypeDef* SPIx, uint8_t SPI_CRC)

{

  uint16_t crcreg = 0;

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  assert_param(IS_SPI_CRC(SPI_CRC));

  if (SPI_CRC != SPI_CRC_Rx)

  {

    /* Get the Tx CRC register */

    crcreg = SPIx->TXCRCR;

  }

  else

  {

    /* Get the Rx CRC register */

    crcreg = SPIx->RXCRCR;

  }

  /* Return the selected CRC register */

  return crcreg;

}

/**

  * @brief  Returns the CRC Polynomial register value for the specified SPI.

  * @param  SPIx: where x can be 1, 2, 3, 4, 5 or 6 to select the SPI peripheral.

  * @retval The CRC Polynomial register value.

  */

uint16_t SPI_GetCRCPolynomial(SPI_TypeDef* SPIx)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH(SPIx));

  /* Return the CRC polynomial register */

  return SPIx->CRCPR;

}

/**

  * @}

  */

/** @defgroup SPI_Group4 DMA transfers management functions

 *  @brief   DMA transfers management functions

  *

@verbatim   

 ===============================================================================

                   ##### DMA transfers management functions #####

 ===============================================================================  

@endverbatim

  * @{

  */

/**

  * @brief  Enables or disables the SPIx/I2Sx DMA interface.

  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2, 3, 4, 5 or 6 

  *         in SPI mode or 2 or 3 in I2S mode or I2Sxext for I2S full duplex mode. 

  * @param  SPI_I2S_DMAReq: specifies the SPI DMA transfer request to be enabled or disabled. 

  *          This parameter can be any combination of the following values:

  *            @arg SPI_I2S_DMAReq_Tx: Tx buffer DMA transfer request

  *            @arg SPI_I2S_DMAReq_Rx: Rx buffer DMA transfer request

  * @param  NewState: new state of the selected SPI DMA transfer request.

  *          This parameter can be: ENABLE or DISABLE.

  * @retval None

  */

void SPI_I2S_DMACmd(SPI_TypeDef* SPIx, uint16_t SPI_I2S_DMAReq, FunctionalState NewState)

{

  /* Check the parameters */

  assert_param(IS_SPI_ALL_PERIPH_EXT(SPIx));

  assert_param(IS_FUNCTIONAL_STATE(NewState));

  assert_param(IS_SPI_I2S_DMAREQ(SPI_I2S_DMAReq));

  if (NewState != DISABLE)

  {

    /* Enable the selected SPI DMA requests */

    SPIx->CR2 |= SPI_I2S_DMAReq;

  }

  else

  {

    /* Disable the selected SPI DMA requests */

    SPIx->CR2 &= (uint16_t)~SPI_I2S_DMAReq;

  }

}