stm32f0xx_spi.c

stm32f0固件库

  *  and the product configuration). But in case the prescaler value is greater 
  *  than 511, the default value (0x02) will be configured instead.     
  * @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;
  RCC_ClocksTypeDef RCC_Clocks;
  uint32_t sourceclock = 0;

  /* Check the I2S parameters */
  assert_param(IS_SPI_1_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;
    }

    /* I2S Clock source is System clock: Get System Clock frequency */
    RCC_GetClocksFreq(&RCC_Clocks);      

    /* Get the source clock value: based on System Clock value */
    sourceclock = RCC_Clocks.SYSCLK_Frequency;    

    /* 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)(((((sourceclock / 256) * 10) / I2S_InitStruct->I2S_AudioFreq)) + 5);
    }
    else
    {
      /* MCLK output is disabled */
      tmp = (uint16_t)(((((sourceclock / (32 * packetlength)) *10 ) / I2S_InitStruct->I2S_AudioFreq)) + 5);
    }
    
    /* Remove the floating 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)(i2sdiv | (uint16_t)(i2sodd | (uint16_t)I2S_InitStruct->I2S_MCLKOutput));

  /* Configure the I2S with the SPI_InitStruct values */
  tmpreg |= (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  Enables or disables the specified SPI peripheral.
  * @param  SPIx: where x can be 1 or 2 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 TI Mode.
  * @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 to select the SPI peripheral.
  * @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_1_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)~((uint16_t)SPI_CR2_FRF);
  }
}

/**
  * @brief  Enables or disables the specified SPI peripheral (in I2S mode).
  * @param  SPIx: where x can be 1 to select the SPI peripheral.
  * @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_1_PERIPH(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 or 2  to select the SPI peripheral.
  * @param  SPI_DataSize: specifies the SPI data size.
  *   For the SPIx peripheral this parameter can be one of the following values:
  *     @arg SPI_DataSize_4b: Set data size to 4 bits
  *     @arg SPI_DataSize_5b: Set data size to 5 bits
  *     @arg SPI_DataSize_6b: Set data size to 6 bits
  *     @arg SPI_DataSize_7b: Set data size to 7 bits
  *     @arg SPI_DataSize_8b: Set data size to 8 bits
  *     @arg SPI_DataSize_9b: Set data size to 9 bits
  *     @arg SPI_DataSize_10b: Set data size to 10 bits
  *     @arg SPI_DataSize_11b: Set data size to 11 bits
  *     @arg SPI_DataSize_12b: Set data size to 12 bits
  *     @arg SPI_DataSize_13b: Set data size to 13 bits
  *     @arg SPI_DataSize_14b: Set data size to 14 bits
  *     @arg SPI_DataSize_15b: Set data size to 15 bits
  *     @arg SPI_DataSize_16b: Set data size to 16 bits
  * @retval None
  */
void SPI_DataSizeConfig(SPI_TypeDef* SPIx, uint16_t SPI_DataSize)
{
  uint16_t tmpreg = 0;
  
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_DATA_SIZE(SPI_DataSize));
  /* Read the CR2 register */
  tmpreg = SPIx->CR2;
  /* Clear DS[3:0] bits */
  tmpreg &= (uint16_t)~SPI_CR2_DS;
  /* Set new DS[3:0] bits value */
  tmpreg |= SPI_DataSize;
  SPIx->CR2 = tmpreg;
}

/**
  * @brief  Configures the FIFO reception threshold for the selected SPI.
  * @param  SPIx: where x can be 1 or 2 to select the SPI peripheral.
  * @param  SPI_RxFIFOThreshold: specifies the FIFO reception threshold.
  *   This parameter can be one of the following values:
  *     @arg SPI_RxFIFOThreshold_HF: RXNE event is generated if the FIFO 
  *          level is greater or equal to 1/2. 
  *     @arg SPI_RxFIFOThreshold_QF: RXNE event is generated if the FIFO 
  *          level is greater or equal to 1/4. 
  * @retval None
  */
void SPI_RxFIFOThresholdConfig(SPI_TypeDef* SPIx, uint16_t SPI_RxFIFOThreshold)
{
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_RX_FIFO_THRESHOLD(SPI_RxFIFOThreshold));

  /* Clear FRXTH bit */
  SPIx->CR2 &= (uint16_t)~((uint16_t)SPI_CR2_FRXTH);

  /* Set new FRXTH bit value */
  SPIx->CR2 |= SPI_RxFIFOThreshold;
}

/**
  * @brief  Selects the data transfer direction in bidirectional mode for the specified SPI.
  * @param  SPIx: where x can be 1 or 2  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.
  * @note   - This function can be called only after the SPI_Init() function has 
  *           been called.  
  * @param  SPIx: where x can be 1 or 2 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.
  * @note   - This function can be called only after the SPI_Init() function has 
  *           been called and the NSS hardware management mode is selected. 
  * @param  SPIx: where x can be 1 or 2 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 |= SPI_CR2_SSOE;
  }
  else
  {
    /* Disable the selected SPI SS output */
    SPIx->CR2 &= (uint16_t)~((uint16_t)SPI_CR2_SSOE);
  }
}

/**
  * @brief  Enables or disables the NSS pulse management mode.
  * @note     This function can be called only after the SPI_Init() function has 
  *           been called. 
  * @note     When TI mode is selected, the control bits NSSP is not taken into