hal_i2c.c

来自「最新版IAR FOR ARM（EWARM）5.11中的代码例子」· C语言 代码 · 共 160 行

//-----------------------------------------------------------------------------
// HAL_I2C
//-----------------------------------------------------------------------------

#include "hal_i2c.h"

//-----------------------------------------------------------------------------
u8 i2c_buffer[12];

//-----------------------------------------------------------------------------
void I2C_Init (void)
{
  I2C->CR   = 0x0;
  I2C->CCR  = 0x0;
  I2C->OAR  = 0x0;
  (void)I2C->SR1;
  (void)I2C->SR2;
}

//-----------------------------------------------------------------------------
void I2C_OnOffConfig (functionalstate Condition)
{
  if (Condition == ENABLE)
  {
    // Enable the I2C selected by setting twice the PE bit on the CR register
    CONFR->GLOBAL_CONTROL &= ~CONFR_nI2C_ENABLE; //Clear this bit to enable I2C pins
    I2C->CR |= CR_PE;
    I2C->CR |= CR_PE;
  } else{
    // Disable the I2C selected
    CONFR->GLOBAL_CONTROL |= CONFR_nI2C_ENABLE; //Set this bit to disable I2C pins, switch into GPIO
    I2C->CR &= ~CR_PE;
  }
}

//-----------------------------------------------------------------------------
void I2C_SpeedConfig (u32 fscl)
{
  if (fscl <= 200000) //<=200kHz
  {
    //Divide by 3 -> Set FM/SM bit
    I2C->CCR  = (FREG_OSC/fscl/3) - 2;
    I2C->CCR |= 0x80;
  } else {
    //Divide by 2 -> Clear FM/SM bit
    I2C->CCR  = (FREG_OSC/fscl/2) - 2;
    I2C->CCR &= 0x7f;
  }
}

//-----------------------------------------------------------------------------
void I2C_AddressConfig (u8 Address)
{
  I2C->OAR = Address;
}

//-----------------------------------------------------------------------------
void I2C_Send_Frame (u8 *pBuffer, u8 NoOfBytes)
{
  u8 i;

  //StartBit
  while (I2C->SR1 & SR1_BUSY);
  if (!I2C_StartBit())
    return;

  //SendBytes
  for (i=0;i<NoOfBytes;i++)
  {
    if (!I2C_SendByte(*(pBuffer+i)))
      return;
  }

  //StopBit
  I2C->CR |= CR_STOP;
}

//-----------------------------------------------------------------------------
void I2C_Receive_Frame (u8 *pBuffer, u8 NoOfBytes)
{
  u8 i;

 //StartBit
  while (I2C->SR1 & SR1_BUSY);
  if (!I2C_StartBit())
    return;

  //Send bytes: SLAVE_ADDR + WRITE_FLAG, REG_ADDR
  if (!I2C_SendByte(*(pBuffer+0)))
    return;
  if (!I2C_SendByte(*(pBuffer+1)))
    return;

  //Repeat StartBit
  if (!I2C_StartBit())
    return;

  //Send byte: SLAVE_ADDR + READ_FLAG
  I2C->DR = *(pBuffer+2);
  while (!(I2C->SR1 & SR1_EVF));
  I2C->CR |= CR_ACK;

  if (!I2C_TestErr())
    return;

  while (!(I2C->SR1 & SR1_BTF));

  //ReceiveBytes, when finish generate StopBit
  for (i=3;i<=NoOfBytes;i++)
  {
    while (!(I2C->SR1 & SR1_EVF));

    if (i < (NoOfBytes-1))
      I2C->CR |= CR_ACK;

    if (i == (NoOfBytes-1))
      I2C->CR &= ~CR_ACK;

    if (i > (NoOfBytes-1))
      I2C->CR |= CR_STOP;

    if (!I2C_TestErr())
      return;

    while (!(I2C->SR1 & SR1_BTF));

    if (i <= (NoOfBytes-1))
      *(pBuffer+i) = I2C->DR;
    else
      (void)I2C->DR;
  }

}

//-----------------------------------------------------------------------------
void i2c_write_reg (u8 slave_addr, u8 reg_addr, u8 reg_value)
{
  i2c_buffer[0] = slave_addr+kSLAVE_ADDR_WRITE;
  i2c_buffer[1] = reg_addr;
  i2c_buffer[2] = reg_value;
  I2C_Send_Frame (&i2c_buffer[0],3);
}

//-----------------------------------------------------------------------------
void i2c_read_reg (u8 slave_addr, u8 reg_addr, u8 NoOfBytes)
{
  i2c_buffer[0] = slave_addr+kSLAVE_ADDR_WRITE;
  i2c_buffer[1] = reg_addr;
  i2c_buffer[2] = slave_addr+kSLAVE_ADDR_READ;
  I2C_Receive_Frame (&i2c_buffer[0],3+NoOfBytes);
}

//-----------------------------------------------------------------------------
u8 i2c_read_buffer (u8 position)
{
  return (i2c_buffer[3+position]);
}

//-----------------------------------------------------------------------------