STM32H7 I2C主机读数据【寄存器操作】

I2C初始化

/* I2C2 init function */
void MX_I2C2_Init(void)
{

  /* USER CODE BEGIN I2C2_Init 0 */

  /* USER CODE END I2C2_Init 0 */

  LL_I2C_InitTypeDef I2C_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  LL_RCC_SetI2CClockSource(LL_RCC_I2C123_CLKSOURCE_PCLK1);

  LL_AHB4_GRP1_EnableClock(LL_AHB4_GRP1_PERIPH_GPIOB);
  /**I2C2 GPIO Configuration
  PB10   ------> I2C2_SCL
  PB11   ------> I2C2_SDA
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_10|LL_GPIO_PIN_11;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_OPENDRAIN;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_4;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_I2C2);

  /* I2C2 interrupt Init */
  NVIC_SetPriority(I2C2_EV_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(I2C2_EV_IRQn);
  NVIC_SetPriority(I2C2_ER_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(I2C2_ER_IRQn);

  /* USER CODE BEGIN I2C2_Init 1 */

  /* USER CODE END I2C2_Init 1 */

  /** I2C Initialization
  */
  LL_I2C_EnableAutoEndMode(I2C2);
  LL_I2C_SetOwnAddress2(I2C2, 0, LL_I2C_OWNADDRESS2_NOMASK);
  LL_I2C_DisableOwnAddress2(I2C2);
  LL_I2C_DisableGeneralCall(I2C2);
  LL_I2C_EnableClockStretching(I2C2);
  I2C_InitStruct.PeripheralMode = LL_I2C_MODE_I2C;
  I2C_InitStruct.Timing = 0x20B0CCFF;
  I2C_InitStruct.AnalogFilter = LL_I2C_ANALOGFILTER_ENABLE;
  I2C_InitStruct.DigitalFilter = 0;
  I2C_InitStruct.OwnAddress1 = 0;
  I2C_InitStruct.TypeAcknowledge = LL_I2C_ACK;
  I2C_InitStruct.OwnAddrSize = LL_I2C_OWNADDRESS1_7BIT;
  LL_I2C_Init(I2C2, &I2C_InitStruct);
  /* USER CODE BEGIN I2C2_Init 2 */

  /* USER CODE END I2C2_Init 2 */

}

 

 

uint8_t I2C_RegRead(I2C_TypeDef *I2CX, uint8_t DevAddr, uint8_t DataAddr, uint8_t *data, uint32_t len)
{
    uint32_t _Len = 0;

    I2CX->CR2 |= ((DevAddr<<1));    //设置设备地址

    I2CX->CR2 |= (1<<16);    //设置长度，最大256Bytes

    I2CX->CR1 |= (1UL<<0); //使能I2C外设
    I2CX->CR2 &= ~(1UL<<10);    //set 0; requests a write transfer
    I2CX->CR2 |= (1UL<<13);    //START
    while(1 == (I2CX->CR2&(1UL<<13)));
    I2CX->TXDR = (DataAddr);
    while(0 == (I2CX->ISR&(1UL<<0))){};

    I2CX->CR2 |= (1UL<<14);    //STOP
    I2CX->ISR |= (1UL<<5); //clear STOPF


    if(len>255) {_Len = 255; len = len - 255;}
    else {_Len = len; len = 0;}
    I2CX->CR2 |= (_Len<<16);    //设置长度，最大256Bytes

    I2CX->CR2 |= (1UL<<10);    //set 1; requests a read transfer
    I2CX->CR1 |= (1UL<<0); //使能I2C外设
    I2CX->CR2 |= (1UL<<13);    //START
    while(1 == (I2CX->CR2&(1UL<<13)));

    while(_Len)
    {
        for(int i = 0; i<_Len; i++)
        {
            while(0 == (I2CX->ISR&(1UL<<2))){};
            *data++ = I2CX->RXDR;
        }

        if(len>255)
        {
            _Len = 255;
            len = len - 255;
        }
        else
        {
            _Len = len;
            len = 0;
        }

        if(_Len)
        {
            I2CX->CR2 &= ~(1UL<<13);    //START
            I2CX->CR2 |= (_Len<<16);    //设置长度，最大256Bytes
            I2CX->CR2 |= (1UL<<13);    //START
        }

    }
    I2CX->CR2 |= (1UL<<14);    //STOP
    I2CX->ISR |= (1UL<<5); //clear STOPF

}

uint8_t I2C_Read(I2C_TypeDef *I2CX, uint8_t DevAddr, uint8_t *data, uint32_t len)
{
    uint32_t _Len = 0;

    I2CX->CR2 |= ((DevAddr<<1));    //设置设备地址
//    I2CX->CR2 |= ((1UL<<24));
//    I2CX->CR2 |= ((1UL<<25));

    if(len>255) {_Len = 255; len = len - 255;}
    else {_Len = len; len = 0;}
    I2CX->CR2 |= (_Len<<16);    //设置长度，最大256Bytes
    I2CX->CR2 |= (1UL<<10);    //set 1; requests a read transfer
    I2CX->CR1 |= (1UL<<0); //使能I2C外设
    I2CX->CR2 |= (1UL<<13);    //START
    while(1 == (I2CX->CR2&(1UL<<13)));

    while(_Len)
    {

        for(int i = 0; i<_Len; i++)
        {
            while(0 == (I2CX->ISR&(1UL<<2))){};
            *data++ = I2CX->RXDR;
        }

        if(len>255)
        {
            _Len = 255;
            len = len - 255;
        }
        else
        {
            _Len = len;
            len = 0;
        }

        if(_Len)
        {
            I2CX->CR2 &= ~(1UL<<13);    //START
            I2CX->CR2 |= (_Len<<16);    //设置长度，最大256Bytes
            I2CX->CR2 |= (1UL<<13);    //START
        }
    }
    I2CX->CR2 |= (1UL<<14);    //STOP
    I2CX->ISR |= (1UL<<5); //clear STOPF

}