STM32F407使用PB9和PB10的I2C初始化并使用DMA进行数据收发并且适合实时系统的完整代码，不使用HAL库，使用标准库

以下是使用PB9和PB10的I2C初始化并使用DMA进行数据收发的完整代码，适用于STM32F407，并且不使用HAL库，使用标准库。

首先，需要在stm32f4xx.h文件中定义I2C的寄存器地址：

#define I2C1_BASE             (PERIPH_BASE + 0x5400)
#define I2C1                  ((I2C_TypeDef *) I2C1_BASE)

#define I2C2_BASE             (PERIPH_BASE + 0x5800)
#define I2C2                  ((I2C_TypeDef *) I2C2_BASE)

#define I2C3_BASE             (PERIPH_BASE + 0x5C00)
#define I2C3                  ((I2C_TypeDef *) I2C3_BASE)

然后，需要定义I2C的初始化函数：

void I2C_Init(I2C_TypeDef* I2Cx, uint32_t ClockSpeed, uint16_t OwnAddress, uint16_t OwnAddressMask)
{
    uint16_t prescaler = 0;
    uint16_t duty_cycle = I2C_DutyCycle_2;

    // Enable I2Cx clock
    if (I2Cx == I2C1)
    {
        RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
    }
    else if (I2Cx == I2C2)
    {
        RCC->APB1ENR |= RCC_APB1ENR_I2C2EN;
    }
    else if (I2Cx == I2C3)
    {
        RCC->APB1ENR |= RCC_APB1ENR_I2C3EN;
    }

    // Reset I2Cx
    I2Cx->CR1 |= I2C_CR1_SWRST;
    I2Cx->CR1 &= ~I2C_CR1_SWRST;

    // Disable I2Cx
    I2Cx->CR1 &= ~I2C_CR1_PE;

    // Calculate prescaler value
    prescaler = (uint16_t)(SystemCoreClock / (ClockSpeed * 2));
    I2Cx->CR2 = prescaler & I2C_CR2_FREQ;

    // Set duty cycle
    I2Cx->CCR = (uint16_t)(prescaler / (ClockSpeed * 3)) & I2C_CCR_CCR;
    I2Cx->CCR |= duty_cycle;

    // Set own address and mask
    I2Cx->OAR1 = OwnAddress << 1;
    I2Cx->OAR2 = OwnAddressMask << 1;

    // Enable DMA
    I2Cx->CR2 |= I2C_CR2_DMAEN;

    // Enable I2Cx
    I2Cx->CR1 |= I2C_CR1_PE;
}

接下来，需要定义I2C的发送和接收函数：

void I2C_Write(I2C_TypeDef* I2Cx, uint8_t addr, uint8_t reg, uint8_t data)
{
    // Wait until I2Cx is ready for transmission
    while (!(I2Cx->SR1 & I2C_SR1_TXE));

    // Send start bit
    I2Cx->CR1 |= I2C_CR1_START;

    // Wait until start bit is sent
    while (!(I2Cx->SR1 & I2C_SR1_SB));

    // Send address
    I2Cx->DR = addr << 1;

    // Wait until address is sent
    while (!(I2Cx->SR1 & I2C_SR1_ADDR));

    // Clear ADDR flag
    (void)I2Cx->SR2;

    // Send register address
    I2Cx->DR = reg;

    // Wait until register address is sent
    while (!(I2Cx->SR1 & I2C_SR1_TXE));

    // Send data
    I2Cx->DR = data;

    // Wait until data is sent
    while (!(I2Cx->SR1 & I2C_SR1_TXE));

    // Send stop bit
    I2Cx->CR1 |= I2C_CR1_STOP;

    // Wait until stop bit is sent
    while (I2Cx->CR1 & I2C_CR1_STOPF);
}

uint8_t I2C_Read(I2C_TypeDef* I2Cx, uint8_t addr, uint8_t reg)
{
    uint8_t data = 0;

    // Wait until I2Cx is ready for transmission
    while (!(I2Cx->SR1 & I2C_SR1_TXE));

    // Send start bit
    I2Cx->CR1 |= I2C_CR1_START;

    // Wait until start bit is sent
    while (!(I2Cx->SR1 & I2C_SR1_SB));

    // Send address
    I2Cx->DR = addr << 1;

    // Wait until address is sent
    while (!(I2Cx->SR1 & I2C_SR1_ADDR));

    // Clear ADDR flag
    (void)I2Cx->SR2;

    // Send register address
    I2Cx->DR = reg;

    // Wait until register address is sent
    while (!(I2Cx->SR1 & I2C_SR1_TXE));

    // Send repeated start bit
    I2Cx->CR1 |= I2C_CR1_START;

    // Wait until start bit is sent
    while (!(I2Cx->SR1 & I2C_SR1_SB));

    // Send address with read bit
    I2Cx->DR = (addr << 1) | 0x01;

    // Wait until address is sent
    while (!(I2Cx->SR1 & I2C_SR1_ADDR));

    // Clear ACK flag
    I2Cx->CR1 &= ~I2C_CR1_ACK;

    // Clear ADDR flag
    (void)I2Cx->SR2;

    // Enable DMA
    I2Cx->CR2 |= I2C_CR2_DMAEN;

    // Enable DMA receive
    I2Cx->CR2 |= I2C_CR2_RD_WRN;

    // Set DMA transfer direction
    DMA1_Stream0->CR &= ~DMA_SxCR_DIR;
    DMA1_Stream0->CR |= DMA_SxCR_DIR_0;

    // Set DMA memory address
    DMA1_Stream0->M0AR = (uint32_t)&data;

    // Set DMA number of data to transfer
    DMA1_Stream0->NDTR = 1;

    // Enable DMA stream
    DMA1_Stream0->CR |= DMA_SxCR_EN;

    // Wait until DMA transfer is complete
    while (!(DMA1->LISR & DMA_LISR_TCIF0));

    // Clear DMA transfer complete flag
    DMA1->LIFCR |= DMA_LIFCR_CTCIF0;

    // Send stop bit
    I2Cx->CR1 |= I2C_CR1_STOP;

    // Wait until stop bit is sent
    while (I2Cx->CR1 & I2C_CR1_STOPF);

    return data;
}

最后，需要定义DMA的初始化函数：

void DMA_Init(void)
{
    // Enable DMA1 clock
    RCC->AHB1ENR |= RCC_AHB1ENR_DMA1EN;

    // Reset DMA1 stream0
    DMA1->LIFCR |= DMA_LIFCR_CTCIF0 | DMA_LIFCR_CHTIF0 | DMA_LIFCR_CTEIF0 | DMA_LIFCR_CDMEIF0;

    // Configure DMA1 stream0
    DMA1_Stream0->CR &= ~DMA_SxCR_CHSEL;
    DMA1_Stream0->CR |= DMA_SxCR_CHSEL_1 | DMA_SxCR_CHSEL_0;  // Channel 7
    DMA1_Stream0->CR |= DMA_SxCR_PL_1;                        // Priority high
    DMA1_Stream0->CR |= DMA_SxCR_MSIZE_0;                     // Memory size 8-bit
    DMA1_Stream0->CR |= DMA_SxCR_PSIZE_0;                     // Peripheral size 8-bit
    DMA1_Stream0->CR |= DMA_SxCR_MINC;                        // Memory increment
    DMA1_Stream0->CR &= ~DMA_SxCR_PINC;                       // Peripheral no increment
    DMA1_Stream0->CR &= ~DMA_SxCR_CIRC;                       // Circular mode disabled
    DMA1_Stream0->CR &= ~DMA_SxCR_DIR;                        // Peripheral to memory
    DMA1_Stream0->CR |= DMA_SxCR_TCIE;                        // Transfer complete interrupt enabled
}

现在，可以在主函数中调用这些函数来初始化I2C和DMA，并进行数据收发：

int main(void)
{
    uint8_t data = 0;

    // Initialize I2C
    I2C_Init(I2C1, 100000, 0x00, 0x00);

    // Initialize DMA
    DMA_Init();

    // Write data to I2C device
    I2C_Write(I2C1, 0xA0, 0x00, 0x01);

    // Read data from I2C device
    data = I2C_Read(I2C1, 0xA0, 0x00);

    while (1)
    {

    }
}

注意：这只是一个简单的示例代码，并且需要根据实际情况进行适当修改。