i2c.c

意法半导体ARM7 STR710+DM9000A的TCP/IP实现

/*******************************************************************************
* Function Name  : I2C_AddressSend
* Description    : Transmits the address byte to select the slave device.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Address: an u16 parameter indicating the slave address
*                  Mode (I2C_Mode10,I2C_Mode7).
*                  Direction (I2C_RX,I2C_TX).
* Return         : None.
********************************************************************************/
void I2C_AddressSend (I2C_TypeDef *I2Cx, u16 Address, I2C_Addressing Mode, I2C_Direction Direction)
{
  if (Mode == I2C_Mode10 )
  /*10 bit addressing mode */
  {
    /* Update the DR register by generated header */
    I2Cx->DR = ((Address>>7)|0xa0)&0xfe;
    /* Wait till I2C_ADD10 flag is set */
    while ((I2Cx->SR1&0x40)==0);
    /* clear I2C_ADD10 flag */
    (void)I2Cx->SR2;
    I2Cx->DR=(u8)Address;
    /* Test on the direction to define the read/write bit */
    if (Direction == I2C_RX)
    {
      /* Wait till I2C_ENDAD flag is set */
      while ((I2Cx->SR2&0x20)==0);
      I2Cx->CR|=0x20;
      /* Repeated START Generate */
      I2C_STARTGenerate (I2Cx, ENABLE);
      /* Test on SB flag status */
      while ((I2Cx->SR1&0x01)==0);
      I2Cx->DR = ((Address>>7)|0xa1);
    }
  }
  else
  /* 7 bit addressing mode */
  {
    if (Direction == I2C_RX) Address|=0x01; else Address&=~0x01;
    I2Cx->DR=(u8)Address;
  }
}

/*******************************************************************************
* Function Name  : I2C_ByteSend
* Description    : Send a single byte of data.
* Input          : I2Cx ( I2C0 or I2C1 )
*                  Data : the byte to be sent to the slave
* Return         : None.
*******************************************************************************/
void I2C_ByteSend (I2C_TypeDef *I2Cx, u8 Data)
{
  /* Write in the DR register the byte to be sent */
  I2Cx->DR = Data;
}


/*******************************************************************************
* Function Name  : I2C_TransmissionStatus
* Description    : Report the NewState of the transmission
* Input          : I2Cx ( I2C0 or I2C1 )
* Return         : I2C_Tx_Status :transmission status (I2C_TX_NO, I2C_TX_SB,
*                   I2C_TX_AF, I2C_TX_ARLO, I2C_TX_BERR,I2C_TX_ADD_OK,
*                   I2C_TX_DATA_OK,I2C_TX_ONGOING)
*******************************************************************************/
I2C_Tx_Status I2C_TransmissionStatus (I2C_TypeDef *I2Cx)
{
  u8 SR1value=0;
  u8 SR2value=0;
  I2C_Tx_Status NewState = I2C_TX_NO;

  SR1value = I2Cx->SR1;
  SR2value = I2Cx->SR2;
  if ((I2Cx->SR1&0x10)==0)
    NewState=I2C_TX_NO;
  else if (I2Cx->SR1&0x01)
    /* I2C_SB bit is set */
    NewState=I2C_TX_SB;
  else if ((SR2value & 0x10)&&(I2Cx->CR&0x04))
    /* I2C_ACK &I2C_AF are both set */
    NewState=I2C_TX_AF;
  else if (SR2value & 0x04)
    /* I2C_ARLO is set in multimaster mode */
    NewState=I2C_TX_ARLO;
  else if (SR2value & 0x02)
    /* I2C_BERR bit is set */
    NewState=I2C_TX_BERR;
  else if ((SR1value & 0x80)&& (I2Cx->SR2&0x20))
    /* I2C_EVF and I2C_ENDAD are both set */
    NewState=I2C_TX_ADD_OK;
  else if ((I2Cx->SR1&0x20)&& (I2Cx->SR1&0x08))
    /* I2C_TRA and I2C_BTF are both set */
    NewState=I2C_TX_DATA_OK;
  else
    NewState=I2C_TX_ONGOING;

  return NewState;
}

/*******************************************************************************
* Function Name  : I2C_ByteReceive
* Description    : Returns the received byte.
* Input          : I2Cx ( I2C0 or I2C1 )
* Return         : the byte received
*******************************************************************************/
u8 I2C_ByteReceive (I2C_TypeDef *I2Cx)
{
   /* Wait till I2C_BTF bit is set */
  while ((I2Cx->SR1 & 0x08)==0);
  return I2Cx->DR;
}


/*******************************************************************************
* Function Name  :I2C_ReceptionStatus
* Description    : Report the reception NewState.
* Input          : I2Cx ( I2C0 or I2C1 )
* Return         : I2C_Rx_Status:the NewState of the reception ( I2C_RX_NO,
*                  I2C_RX_SB,I2C_RX_AF,I2C_RX_ARLO,I2C_RX_BERR,I2C_RX_ADD_OK,
*                  I2C_RX_DATA_OK, I2C_RX_ONGOING)
*******************************************************************************/
I2C_Rx_Status I2C_ReceptionStatus (I2C_TypeDef *I2Cx)
{
  u8 SR1value=0;
  u8 SR2value=0;
  I2C_Rx_Status NewState = I2C_RX_NO;
  SR1value= I2Cx->SR1;
  SR2value= I2Cx->SR2;

  if ((I2Cx->SR1&0x10) == 0)
    NewState=I2C_RX_NO;
  else if (I2Cx->SR1&0x01)
    /* I2C_SB bit is set */
    NewState=I2C_RX_SB;
  else if ((SR2value & 0x10) && (I2Cx->CR&0x04))
    /* I2C_ACK &I2C_AF are both set */
    NewState=I2C_RX_AF;
  else if (SR2value & 0x04)
    /* I2C_ARLO is set */
    NewState=I2C_RX_ARLO;
  else if (SR2value & 0x02)
    /* I2C_BERR bit is set */
    NewState=I2C_RX_BERR;
  else if ((SR1value & 0x80) && (I2Cx->SR1&0x08)==0)
    /* I2C_EVF is set & I2C_BTF is not set */
    NewState=I2C_RX_ADD_OK;
  else if ((I2Cx->SR1&0x20)==0 && (I2Cx->SR1&0x08))
    /* I2C_TRA is cleared & I2C_BTF is set */
    NewState=I2C_RX_DATA_OK;
  else
  NewState=I2C_RX_ONGOING;
  return NewState;
}

/******************* (C) COPYRIGHT 2003 STMicroelectronics *****END OF FILE****/


/*******************************************************************************
* Function Name  : I2C_GetLastEvent                                  
* Description    : Gets the last I2Cx event that has occurred.                  
* Input          : - I2Cx: specifies the I2C to read its flags, it can be:
*                     I2C0, I2C1.  
* Output         : None.                          
* Return         : The Last happened Event.                           
*******************************************************************************/
u16 I2C_GetLastEvent(I2C_TypeDef *I2Cx)
{
  u16 Flag1 = 0, Flag2 = 0, LastEvent = 0;

  Flag1 = I2Cx->SR1;
  Flag2 = I2Cx->SR2;
  Flag2 = Flag2<<8;
  /* Get the last event value from I2C status register */
  LastEvent = (((Flag1 | (Flag2)) & I2C_Event_Mask));
  /* Return the last event */
  return LastEvent;
}




/*******************************************************************************
* Function Name  : I2C_CheckEvent                                         
* Description    : Checks whether the Last I2C Event is equal to the one passed 
*                  as parameter.                                              
* Input          : - I2Cx: specifies the I2C to read its flags, it can be:
*                     I2C0, I2C1
                   - I2C_EVENT: specifies the event to be checked. This parameter
*                    can be one of the following values:
*                         - I2C_EVENT_SLAVE_ADDRESS_MATCHED
*                         - I2C_EVENT_SLAVE_BYTE_RECEIVED
*                         - I2C_EVENT_SLAVE_BYTE_TRANSMITTED
*                         - I2C_EVENT_SLAVE_ACK_FAILURE 
*                         - I2C_EVENT_MASTER_MODE_SELECT
*                         - I2C_EVENT_MASTER_MODE_SELECTED
*                         - I2C_EVENT_MASTER_BYTE_RECEIVED
*                         - I2C_EVENT_MASTER_BYTE_TRANSMITTED
*                         - I2C_EVENT_MASTER_MODE_ADDRESS10
*                         - I2C_EVENT_SLAVE_STOP_DETECTED
* Output         : None                                      
* Return         : An FlagStatus enumuration value:
*                         - SET: Last event is equal to the I2C_Event
*                         - RESET: Last event is different from the I2C_Event        
*******************************************************************************/
FlagStatus I2C_CheckEvent(I2C_TypeDef *I2Cx, u16 I2C_EVENT)
{
  u16  LastEvent = I2C_GetLastEvent(I2Cx);

  /* Check whether the last event is equal to I2C_EVENT */
  if (LastEvent == I2C_EVENT)
  {
    /* Return SUCCESS when last event is equal to I2C_EVENT */
    return SET;
  }
  else
  {
    /* Return ERROR when last event is different from I2C_EVENT */
    return RESET;
  }
}