STM32F207 I2C 测试失败

我正在使用 STM32F207 微控制器在 STM3220G-EVAL 板上学习嵌入式开发。我尝试通过连接同一芯片上的两个 I2C2 和 I2C3 模块并发送/接收字符来测试 I2C 接口。这是我当前编写的代码（使用 mdk-arm 5）：

#include <stm32f2xx.h>

volatile uint8_t data = 'a', recv = 'x';

void i2c_init(void);

void I2C2_EV_IRQHandler(void)
{
    volatile uint16_t stat, dummy;
    stat = I2C2->SR1;
    switch(stat)
    {
        // SB set; read SR1 and write slave address in DR to clear
        case 0x01:
            dummy = I2C2->SR1;
            // Send address of slave
            I2C2->DR = (0x08 << 1);
            break;
        // ADDR set; read SR1 and SR2 to clear
        case 0x02:
            dummy = I2C2->SR1;
            dummy = I2C2->SR2;
            break;
        // TxE set; write to DR to clear
        case 0x80:
            I2C2->DR = data;
            break;
        // TxE and BTF set; generate stop condition to clear
        case 0x84:
            // Generate stop
            I2C2->CR1 |= (1 << 9);
            break;
    }
}

void I2C3_EV_IRQHandler(void)
{
    volatile uint16_t stat, dummy;
    stat = I2C3->SR1;
    switch(stat)
    {
        // ADDR set; read SR1 and SR2 to clear
        case 0x02:
            dummy = I2C3->SR1;
            dummy = I2C3->SR2;
            break;
        // STOPF set; read SR1 and write CR1 to clear
        case 0x10:
            dummy = I2C3->SR1;
            I2C3->CR1 &= ~(1 << 0);
            break;
        // RxNE set; read DR to clear
        case 0x40:
            recv = I2C3->DR;
            break;
    }
}

int main()
{
    i2c_init();
    // Generate START condition
    I2C2->CR1 |= (1 << 8);
    while(1)
    {
        if(!(I2C2->OAR1 & (1 << 14)))
            I2C2->OAR1 |= (1 << 14);
        if(!(I2C3->OAR1 & (1 << 14)))
            I2C3->OAR1 |= (1 << 14);
        if(recv != 'x')
            break;
    }
    return 0;
}

void i2c_init(void)
{
    // Enable GPIOA, GPIOC, GPIOF, I2C2 and I2C3 peripherals
    RCC->AHB1ENR |= (1 << 0);
    RCC->AHB1ENR |= (1 << 2);
    RCC->AHB1ENR |= (1 << 5);
    RCC->APB1ENR |= (1 << 22);
    RCC->APB1ENR |= (1 << 23);
    // Set GPIO mode to AF
    GPIOA->MODER |= (1 << 17);
    GPIOC->MODER |= (1 << 19);
    GPIOF->MODER |= (1 << 1);
    GPIOF->MODER |= (1 << 3);
    // Set GPIO type to OD
    GPIOA->OTYPER |= (1 << 8);
    GPIOC->OTYPER |= (1 << 9);
    GPIOF->OTYPER |= (1 << 0);
    GPIOF->OTYPER |= (1 << 1);
    // Set GPIO speed to 50MHz
    GPIOA->OSPEEDR |= (1 << 17);
    GPIOC->OSPEEDR |= (1 << 19);
    GPIOF->OSPEEDR |= (1 << 1);
    GPIOF->OSPEEDR |= (1 << 3);
    // Link to AFs
    GPIOA->AFR[1] |= (1 << 2);
    GPIOC->AFR[1] |= (1 << 6);
    GPIOF->AFR[0] |= (1 << 2);
    GPIOF->AFR[0] |= (1 << 6);
    // Reset clocks
    I2C2->CR2 = 0x00;
    I2C3->CR2 = 0x00;
    I2C2->CCR = 0x00;
    I2C3->CCR = 0x00;
    // Enable interrupts
    I2C2->CR2 |= (1 << 9);
    I2C2->CR2 |= (1 << 10);
    I2C3->CR2 |= (1 << 9);
    I2C3->CR2 |= (1 << 10);
    NVIC_EnableIRQ(I2C2_EV_IRQn);
    NVIC_EnableIRQ(I2C3_EV_IRQn);
    // Must set bit 14 in OAR1 to 1
    I2C2->OAR1 |= (1 << 14);
    I2C3->OAR1 |= (1 << 14);
    // Set addresses
    I2C2->OAR1 = (0x04 << 1);
    I2C3->OAR1 = (0x08 << 1);
    // Set peripheral clock frequency
    I2C2->CR2 |= 0x08;
    I2C3->CR2 |= 0x08;
    I2C2->CCR |= 0x28;
    I2C3->CCR |= 0x28;
    I2C2->TRISE = 0x09;
    I2C3->TRISE = 0x09;
    // Enable ACK
    I2C2->CR1 |= (1 << 10);
    I2C3->CR1 |= (1 << 10);
    // Enable I2C peripherals
    I2C2->CR1 |= (1 << 0);
    I2C3->CR1 |= (1 << 0);
}

我面临的问题是：

1. 执行永远不会进入中断处理程序（由 断点）
2. 即使我在 CR1 中设置了 START 位，主机（I2C2）的 SR1 中的 SB 位也从未设置
3. SDA 线为高电平，但 SCL 线被拉低

我在 SDA 上使用 13K 上拉电阻，在 SCL 上使用 10K 上拉电阻。使用的引脚号为 PF0、PF1（I2C2 SDA、SCL）和 PA8、PC9（I2C3 SCL、SDA）。 使用内部或外部上拉电阻会导致 SR2 寄存器显示总线忙。 另外我还没有在 RTE_Device.h 中启用 I2C2 和 I2C3。它似乎只是提供了方便的 typedef。 (EDIT :尝试启用这些，但没有帮助）

有人能帮我解决这个问题吗？我似乎走进了死胡同。

(EDIT :在板上设置一些跳线后，主事件处理程序将被成功调用。但仍然存在一些问题。现在正在设置确认失败位，并且不会调用从属处理程序。已验证总线线路在空闲时为高电平。）

很抱歉迟到了，但我已经通过使用 ST 提供的 STM32 CPAL 库成功解决了这个问题。我通过读取加速度计中的“WHO_AM_I”寄存器，使用板载加速度计测试了该库。其代码是：

#include "cpal_i2c.h"

int main()
{
    // Configuration
    CPAL_TransferTypeDef RxStruct;
    uint8_t RxBuf;
    RxStruct.pbBuffer = &RxBuf;
    RxStruct.wAddr1 = 0x39;
    // Initialization
    CPAL_I2C_StructInit(&I2C1_DevStructure);
    I2C1_DevStructure.CPAL_Mode = CPAL_MODE_MASTER;
    I2C1_DevStructure.CPAL_ProgModel = CPAL_PROGMODEL_DMA;
    I2C1_DevStructure.pCPAL_I2C_Struct->I2C_ClockSpeed = 100000;
    I2C1_DevStructure.pCPAL_TransferRx = &RxStruct;
    I2C1_DevStructure.pCPAL_TransferTx = pNULL;
    CPAL_I2C_Init(&I2C1_DevStructure);
    // Communication
    RxStruct.wNumData = 1;
    RxStruct.wAddr2 = 0x0F;
    if(CPAL_I2C_Read(&I2C1_DevStructure) != CPAL_PASS)
    {
        // Error
    }
    while(I2C1_DevStructure.CPAL_State != CPAL_STATE_READY);
    while(1);
    return 0;
}