视频讲解

实验过程

查看原理图中定义的I2C的管脚，PB0和PB1
在board.ve中定义的引脚功能

I2C0_SDA PIN_36
I2C0_SCL PIN_35

新建工程
测试代码

#include "board.h"#define MIN_IRQ_PRIORITY 1
#define MAX_IRQ_PRIORITY PLIC_MAX_PRIORITY
#define I2C_PRIORITY    (MIN_IRQ_PRIORITY + 1)void I2cISR()
{I2C_ClearInt(I2C0);
}int main(void)
{board_init();plic_isr[I2C0_IRQn] = I2cISR;PERIPHERAL_ENABLE(I2C, 0);INT_EnableIRQ(I2C0_IRQn, I2C_PRIORITY);uint32_t frequency = 400e3;I2C_Init(I2C0, frequency);uint32_t pclk_freq = SYS_GetPclkFreq();uint16_t prescaler = I2C_GetPrescaler(I2C0);printf("I2C frequency: %d, prescaler: %d, apb clk frequency: %d\n", frequency, prescaler, pclk_freq);if (fabs((prescaler + 1) * 5.0 * frequency / pclk_freq - 1) > 0.01) {printf("I2C prescaler read mismatch, 0x%02x%02x, %d, %d\n", I2C0->PRERHI, I2C0->PRERLO, frequency, pclk_freq);return false;}I2C_Enable(I2C0);#define LSM6DSR_IIC_ADDR 0x68#define LSM6DSR_WHO_AM_I 0x75I2C_StartSend(I2C0, LSM6DSR_IIC_ADDR);I2C_SendData(I2C0, LSM6DSR_WHO_AM_I);I2C_StartReceive(I2C0, LSM6DSR_IIC_ADDR);I2C_WaitForTransfer(I2C0);uint8_t data;data = I2C_StopReceiveWait(I2C0);// data = I2C_ReceiveDataWait(I2C0);printf("who am i is %x", data);return 0;
}

串口调试终端输出，who am i 寄存器数据符合预期
通过逻辑分析仪抓取的I2C波形