stm32f3的i2c有三种模式：Reload、AutoEnd、SoftEnd模式。
i2c每发送完一个字节，就会产生TXIS标志，当发送完最后一个字节时：
对于Reload模式，当字节大于255字节时，必须使用此模式，此模式下发送结束后，会产生tcr标志。
对于AutoEnd模式，发送后最后一个字节时，会自动产生STOP。
对于SoftEnd模式，发送完最后一个字节时，会产生tc标志，对于发送过程中需要Restart的需要使用此模式。
对于AD5934的读操作，可以事先工作在SoftEnd模式，发送完block read与number bytes read字节后，再转入AutoEnd模式进行Restart，读取完指定的字节后自动产生STOP。操作流程如下：
HAL_StatusTypeDef HAL_I2C_Mem_Read_AD5934_Block(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress, uint16_t MemAddSize, uint8_t *pData, uint16_t Size, uint32_t Timeout)
{
uint32_t Sizetmp = 0;
/* Check the parameters http://tiyubisai.com/video_news/news_135585.html */
assert_param(IS_I2C_MEMADD_SIZE(MemAddSize));
if(hi2c->State == HAL_I2C_STATE_READY)
{
if((pData == NULL) || (Size == 0))
{
return HAL_ERROR;
}
if(__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_BUSY) == SET)
{
return HAL_BUSY;
}
/* Process Locked */
__HAL_LOCK(hi2c);
hi2c->State = HAL_I2C_STATE_MEM_BUSY_RX;
hi2c->ErrorCode = HAL_I2C_ERROR_NONE;
/*
//Send Slave Address and Memory Address
if(I2C_RequestMemoryRead(hi2c, DevAddress, MemAddress, MemAddSize, Timeout) != HAL_OK)
{
if(hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
// Process Unlocked
__HAL_UNLOCK(hi2c);
return HAL_ERROR;
}
else
{
// Process Unlocked
__HAL_UNLOCK(hi2c);
return HAL_TIMEOUT;
}
}*/
I2C_TransferConfig(hi2c,DevAddress,MemAddSize+1, I2C_SOFTEND_MODE, I2C_GENERATE_START_WRITE);
/* Wait until TXIS flag is set */
if(I2C_WaitOnTXISFlagUntilTimeout(hi2c, Timeout) != HAL_OK)
{
if(hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
/* If Memory address size is 8Bit */
if(MemAddSize == I2C_MEMADD_SIZE_8BIT)
{
/* Send Memory Address */
hi2c->Instance->TXDR = __HAL_I2C_MEM_ADD_LSB(MemAddress);
}
/* If Mememory address size is 16Bit */
else
{
/* Send MSB of Memory Address */
hi2c->Instance->TXDR = __HAL_I2C_MEM_ADD_MSB(MemAddress);
/* Wait until TXIS flag is set */
if(I2C_WaitOnTXISFlagUntilTimeout(hi2c, Timeout) != HAL_OK)
{
if(hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
/* Send LSB of Memory Address */
hi2c->Instance->TXDR = __HAL_I2C_MEM_ADD_LSB(MemAddress);
}
/* Wait until TXIS flag is set */
if(I2C_WaitOnTXISFlagUntilTimeout(hi2c, Timeout) != HAL_OK)
{
if(hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
hi2c->Instance->TXDR = Size;
/* Wait until TC flag is set */
if(I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TC, RESET, Timeout) != HAL_OK)
{
return HAL_TIMEOUT;
}
/* Send Slave Address */
/* Set NBYTES to write and reload if size > 255 and generate RESTART */
/* Size > 255, need to set RELOAD bit */
if(Size > 255)
{
I2C_TransferConfig(hi2c,DevAddress,255, I2C_RELOAD_MODE, I2C_GENERATE_START_READ);
Sizetmp = 255;
}
else
{
I2C_TransferConfig(hi2c,DevAddress,Size, I2C_AUTOEND_MODE, I2C_GENERATE_START_READ);
Sizetmp = Size;
}
do
{
/* Wait until RXNE flag is set */
if(I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_RXNE, RESET, Timeout) != HAL_OK)
{
return HAL_TIMEOUT;
}
/* Read data from RXDR */
(*pData++) = hi2c->Instance->RXDR;
/* Decrement the Size counter */
Sizetmp--;
Size--;
if((Sizetmp == 0)&&(Size!=0))
{
/* Wait until TCR flag is set */
if(I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TCR, RESET, Timeout) != HAL_OK)
{
return HAL_TIMEOUT;
}
if(Size > 255)
{
I2C_TransferConfig(hi2c,DevAddress,255, I2C_RELOAD_MODE, I2C_NO_STARTSTOP);
Sizetmp = 255;
}
else
{
I2C_TransferConfig(hi2c,DevAddress,Size, I2C_AUTOEND_MODE, I2C_NO_STARTSTOP);
Sizetmp = Size;
}
}
}while(Size > 0);
/* No need to Check TC flag, with AUTOEND mode the stop is automatically generated */
/* Wait until STOPF flag is reset */
if(I2C_WaitOnSTOPFlagUntilTimeout(hi2c, I2C_TIMEOUT_STOPF) != HAL_OK)
{
if(hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
/* Clear STOP Flag */
__HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_STOPF);
/* Clear Configuration Register 2 */
__HAL_I2C_RESET_CR2(hi2c);
hi2c->State = HAL_I2C_STATE_READY;
/* Process Unlocked */
__HAL_UNLOCK(hi2c);
return HAL_OK;
}
else
{
return HAL_BUSY;
}
}
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