Example #1
0
void I2C_Enable(void)
{
  I2C_Struct_init.I2C_Mode = I2C_Mode_I2C;
  I2C_Struct_init.I2C_Ack = I2C_Ack_Disable;
  I2C_Struct_init.I2C_OwnAddress1 = IS_I2C_OWN_ADDRESS1(0x01);
  I2C_Init(I2C1,&I2C_Struct_init); 
  I2C_Cmd(I2C1, ENABLE);
  I2C_AutoEndCmd(I2C1, ENABLE);
  I2C_NumberOfBytesConfig(I2C1,2);
};
/**
  * @brief  Initializes the I2Cx peripheral according to the specified 
  *   parameters in the I2C_InitStruct.
  * @param  I2Cx: where x can be 1 or 2 to select the I2C peripheral.
  * @param  I2C_InitStruct: pointer to a I2C_InitTypeDef structure that
  *   contains the configuration information for the specified I2C peripheral.
  * @retval None
  */
void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct)
{
  uint16_t tmpreg = 0, freqrange = 0;
  uint16_t result = 0x04;
  uint32_t pclk1 = 8000000;
  RCC_ClocksTypeDef  rcc_clocks;
  /* Check the parameters */
  assert_param(IS_I2C_ALL_PERIPH(I2Cx));
  assert_param(IS_I2C_CLOCK_SPEED(I2C_InitStruct->I2C_ClockSpeed));
  assert_param(IS_I2C_MODE(I2C_InitStruct->I2C_Mode));
  assert_param(IS_I2C_DUTY_CYCLE(I2C_InitStruct->I2C_DutyCycle));
  assert_param(IS_I2C_OWN_ADDRESS1(I2C_InitStruct->I2C_OwnAddress1));
  assert_param(IS_I2C_ACK_STATE(I2C_InitStruct->I2C_Ack));
  assert_param(IS_I2C_ACKNOWLEDGE_ADDRESS(I2C_InitStruct->I2C_AcknowledgedAddress));

/*---------------------------- I2Cx CR2 Configuration ------------------------*/
  /* Get the I2Cx CR2 value */
  tmpreg = I2Cx->CR2;
  /* Clear frequency FREQ[5:0] bits */
  tmpreg &= CR2_FREQ_Reset;
  /* Get pclk1 frequency value */
  RCC_GetClocksFreq(&rcc_clocks);
  pclk1 = rcc_clocks.PCLK1_Frequency;
  /* Set frequency bits depending on pclk1 value */
  freqrange = (uint16_t)(pclk1 / 1000000);
  tmpreg |= freqrange;
  /* Write to I2Cx CR2 */
  I2Cx->CR2 = tmpreg;

/*---------------------------- I2Cx CCR Configuration ------------------------*/
  /* Disable the selected I2C peripheral to configure TRISE */
  I2Cx->CR1 &= CR1_PE_Reset;
  /* Reset tmpreg value */
  /* Clear F/S, DUTY and CCR[11:0] bits */
  tmpreg = 0;

  /* Configure speed in standard mode */
  if (I2C_InitStruct->I2C_ClockSpeed <= 100000)
  {
    /* Standard mode speed calculate */
    result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed << 1));
    /* Test if CCR value is under 0x4*/
    if (result < 0x04)
    {
      /* Set minimum allowed value */
      result = 0x04;  
    }
    /* Set speed value for standard mode */
    tmpreg |= result;	  

    // [ILG]
    #if defined ( __GNUC__ )
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wconversion"
    #endif

    /* Set Maximum Rise Time for standard mode */
    I2Cx->TRISE = freqrange + 1;
    
    // [ILG]
    #if defined ( __GNUC__ )
    #pragma GCC diagnostic pop
    #endif
    
  }
  /* Configure speed in fast mode */
  else /*(I2C_InitStruct->I2C_ClockSpeed <= 400000)*/
  {
    if (I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_2)
    {
      /* Fast mode speed calculate: Tlow/Thigh = 2 */
      result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 3));
    }
    else /*I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_16_9*/
    {
      /* Fast mode speed calculate: Tlow/Thigh = 16/9 */
      result = (uint16_t)(pclk1 / (I2C_InitStruct->I2C_ClockSpeed * 25));
      /* Set DUTY bit */
      result |= I2C_DutyCycle_16_9;
    }

    /* Test if CCR value is under 0x1*/
    if ((result & CCR_CCR_Set) == 0)
    {
      /* Set minimum allowed value */
      result |= (uint16_t)0x0001;  
    }
    /* Set speed value and set F/S bit for fast mode */
    tmpreg |= (uint16_t)(result | CCR_FS_Set);
    /* Set Maximum Rise Time for fast mode */
    I2Cx->TRISE = (uint16_t)(((freqrange * (uint16_t)300) / (uint16_t)1000) + (uint16_t)1);  
  }

  /* Write to I2Cx CCR */
  I2Cx->CCR = tmpreg;
  /* Enable the selected I2C peripheral */
  I2Cx->CR1 |= CR1_PE_Set;

/*---------------------------- I2Cx CR1 Configuration ------------------------*/
  /* Get the I2Cx CR1 value */
  tmpreg = I2Cx->CR1;
  /* Clear ACK, SMBTYPE and  SMBUS bits */
  tmpreg &= CR1_CLEAR_Mask;
  /* Configure I2Cx: mode and acknowledgement */
  /* Set SMBTYPE and SMBUS bits according to I2C_Mode value */
  /* Set ACK bit according to I2C_Ack value */
  tmpreg |= (uint16_t)((uint32_t)I2C_InitStruct->I2C_Mode | I2C_InitStruct->I2C_Ack);
  /* Write to I2Cx CR1 */
  I2Cx->CR1 = tmpreg;

/*---------------------------- I2Cx OAR1 Configuration -----------------------*/
  /* Set I2Cx Own Address1 and acknowledged address */
  I2Cx->OAR1 = (I2C_InitStruct->I2C_AcknowledgedAddress | I2C_InitStruct->I2C_OwnAddress1);
}
/*******************************************************************************
* Function Name  : I2C_Init
* Description    : Initializes the I2Cx peripheral according to the specified 
*                  parameters in the I2C_InitStruct.
* Input          : - I2Cx: where x can be 1 or 2 to select the I2C peripheral.
*                  - I2C_InitStruct: pointer to a I2C_InitTypeDef structure that
*                    contains the configuration information for the specified
*                    I2C peripheral.
* Output         : None
* Return         : None
******************************************************************************/
void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct)
{
  u16 tmpreg = 0, freqrange = 0;
  u16 result = 0x04;
  u32 pclk1clock = 12000000;
  RCC_ClocksTypeDef  RCC_Clocks;

  /* Check the parameters */
  assert_param(IS_I2C_MODE(I2C_InitStruct->I2C_Mode));
  assert_param(IS_I2C_DUTY_CYCLE(I2C_InitStruct->I2C_DutyCycle));
  assert_param(IS_I2C_OWN_ADDRESS1(I2C_InitStruct->I2C_OwnAddress1));
  assert_param(IS_I2C_ACK_STATE(I2C_InitStruct->I2C_Ack));
  assert_param(IS_I2C_ACKNOWLEDGE_ADDRESS(I2C_InitStruct->I2C_AcknowledgedAddress));
  assert_param(IS_I2C_CLOCK_SPEED(I2C_InitStruct->I2C_ClockSpeed));

/*---------------------------- I2Cx CR2 Configuration ------------------------*/
  /* Get the I2Cx CR2 value */
  tmpreg = I2Cx->CR2;
  /* Clear frequency FREQ[5:0] bits */
  tmpreg &= CR2_FREQ_Reset;
  /* Get PCLK1Clock frequency value */
  RCC_GetClocksFreq(&RCC_Clocks);
  pclk1clock = RCC_Clocks.PCLK1_Frequency;
  /* Set frequency bits depending on PCLK1Clock value */
  freqrange = (u16)(pclk1clock / 1000000);
  tmpreg |= freqrange;
  /* Write to I2Cx CR2 */
  I2Cx->CR2 = tmpreg;

/*---------------------------- I2Cx CCR Configuration ------------------------*/
  /* Disable I2Cx to configure TRISE */
  I2C_Cmd(I2Cx, DISABLE);

  /* Reset tmpreg value */
  /* Clear F/S, DUTY and CCR[11:0] bits */
  tmpreg = 0;

  /* Configure speed in standard mode */
  if (I2C_InitStruct->I2C_ClockSpeed <= 100000)
  {
    /* Standard mode speed calculate */
    result = (u16)(pclk1clock / (I2C_InitStruct->I2C_ClockSpeed << 1));
    /* Test if CCR value is under 0x4*/
    if (result < 0x04)
    {
      /* Set minimum allowed value */
      result = 0x04;  
    }
    /* Set speed value for standard mode */
    tmpreg |= result;	  
    /* Set Maximum Rise Time: ((1000/(1000000000/pclk1clock))+1 */
    I2Cx->TRISE = freqrange + 1; 
  }
  /* Configure speed in fast mode */
  else /*(I2C_InitStruct->I2C_ClockSpeed <= 400000)*/
  {
    if (I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_2)
    {
      /* Fast mode speed calculate: Tlow/Thigh = 2 */
      result = (u16)(pclk1clock / (I2C_InitStruct->I2C_ClockSpeed * 3));
    }
    else /*I2C_InitStruct->I2C_DutyCycle == I2C_DutyCycle_16_9*/
    {
      /* Fast mode speed calculate: Tlow/Thigh = 16/9 */
      result = (u16)(pclk1clock / (I2C_InitStruct->I2C_ClockSpeed * 25));
      /* Set DUTY bit */
      result |= I2C_DutyCycle_16_9;
    }
    /* Test if CCR value is under 0x1*/
    if ((result & CCR_CCR_Set) == 0)
    {
      /* Set minimum allowed value */
      result |= (u16)0x0001;  
    }
    /* Set speed value and set F/S bit for fast mode */
    tmpreg |= result | CCR_FS_Set;
    /* Set Maximum Rise Time: ((300/(1000000000/pclk1clock))+1 */
    I2Cx->TRISE = (u16)(((freqrange * 300) / 1000) + 1);  
  }
  /* Write to I2Cx CCR */
  I2Cx->CCR = tmpreg;

  /* Enable I2Cx */
  I2C_Cmd(I2Cx, ENABLE);

/*---------------------------- I2Cx CR1 Configuration ------------------------*/
  /* Get the I2Cx CR1 value */
  tmpreg = I2Cx->CR1;
  /* Clear ACK, SMBTYPE and  SMBUS bits */
  tmpreg &= CR1_CLEAR_Mask;
  /* Configure I2Cx: mode and acknowledgement */
  /* Set SMBTYPE and SMBUS bits according to I2C_Mode value */
  /* Set ACK bit according to I2C_Ack value */
  tmpreg |= (u16)((u32)I2C_InitStruct->I2C_Mode | I2C_InitStruct->I2C_Ack);
  /* Write to I2Cx CR1 */
  I2Cx->CR1 = tmpreg;

/*---------------------------- I2Cx OAR1 Configuration -----------------------*/
  /* Set I2Cx Own Address1 and acknowledged address */
  I2Cx->OAR1 = (I2C_InitStruct->I2C_AcknowledgedAddress | I2C_InitStruct->I2C_OwnAddress1);
}