gd32can功能配置及注释

以下是基于GD32F3xx系列芯片的CAN功能配置及注释示例：

#include "gd32f3xx.h"

void CAN_Configuration(void)
{
    /* 使能CAN时钟 */
    rcu_periph_clock_enable(RCU_CAN0);

    /* 配置CAN GPIO */
    gpio_mode_set(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO_PIN_8 | GPIO_PIN_9);
    gpio_output_options_set(GPIOB, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_8 | GPIO_PIN_9);
    gpio_af_set(GPIOB, GPIO_AF_9, GPIO_PIN_8 | GPIO_PIN_9);

    /* CAN 初始化 */
    can_deinit(CAN0);
    can_struct_para_init(&can_init_struct);

    /* 定义CAN时钟分频 */
    can_init_struct.can_frequency = 36000000U;

    /* 定义CAN位速率 */
    can_init_struct.can_tx_sjw = CAN_SJW_1TQ;
    can_init_struct.can_rx_sjw = CAN_SJW_1TQ;
    can_init_struct.can_bs1 = CAN_BS1_13TQ;
    can_init_struct.can_bs2 = CAN_BS2_2TQ;

    /* 定义过滤器 */
    can_filter_struct_para_init(&can_filter_init_struct);

    /* 过滤器模式 */
    can_filter_init_struct.can_filter_bits = CAN_FILTERBITS_32BIT;

    /* 过滤器ID */
    can_filter_init_struct.can_filter_id_high = 0x0000;
    can_filter_init_struct.can_filter_id_low = 0x0000;

    /* 过滤器掩码 */
    can_filter_init_struct.can_filter_mask_id_high = 0x0000;
    can_filter_init_struct.can_filter_mask_id_low = 0x0000;

    /* 过滤器FIFO */
    can_filter_init_struct.can_filter_fifo_number = CAN_FIFO0;

    /* 过滤器使能 */
    can_filter_enable(CAN0, 0);

    /* CAN 初始化 */
    can_init(CAN0, &can_init_struct);

    /* 配置CAN中断 */
    nvic_irq_enable(CAN0_RX0_IRQn, 0, 0);
    can_interrupt_enable(CAN0, CAN_INTEN_RFNEIE0);

    /* 启动CAN */
    can_enable(CAN0);
}

void CAN_Transmit(uint8_t* data, uint8_t len, uint32_t id)
{
    can_trasnmit_message_struct transmit_message;

    /* 定义传输结构体 */
    can_struct_para_init(&transmit_message);

    /* 定义传输格式 */
    transmit_message.tx_sfid = id;
    transmit_message.tx_efid = 0x00;
    transmit_message.tx_ff = CAN_FF_STANDARD;
    transmit_message.tx_ft = CAN_FT_DATA;

    /* 定义传输数据 */
    for (uint8_t i = 0; i < len; i++)
    {
        transmit_message.tx_data[i] = data[i];
    }

    /* 定义传输数据长度 */
    transmit_message.tx_dlen = len;

    /* 发送消息 */
    can_message_transmit(CAN0, &transmit_message);
}

void CAN_Receive(uint8_t* data, uint8_t* len, uint32_t* id)
{
    can_receive_message_struct receive_message;

    /* 定义接收结构体 */
    can_struct_para_init(&receive_message);

    /* 接收消息 */
    can_message_receive(CAN0, CAN_FIFO0, &receive_message);

    /* 获取接收数据 */
    *id = receive_message.rx_sfid;
    *len = receive_message.rx_dlen;
    for (uint8_t i = 0; i < *len; i++)
    {
        data[i] = receive_message.rx_data[i];
    }
}

注释：

1. `CAN_Transmit`函数：定义CAN发送函数
2. `can_trasnmit_message_struct`：CAN发送结构体，使用`can_struct_para_init`函数初始化为默认值
3. `transmit_message.tx_sfid = id`：定义CAN标准帧ID
4. `transmit_message.tx_ff = CAN_FF_STANDARD`：定义CAN标准帧格式
5. `transmit_message.tx_ft = CAN_FT_DATA`：定义CAN数据帧类型
6. `transmit_message.tx_data[i] = data[i]`：定义CAN数据
7. `transmit_message.tx_dlen = len`：定义CAN数据长度
8. `can_message_transmit(CAN0, &transmit_message)`：发送CAN消息
9. `CAN_Receive`函数：定义CAN接收函数
10. `can_receive_message_struct`：CAN接收结构体，使用`can_struct_para_init`函数初始化为默认值
11. `can_message_receive(CAN0, CAN_FIFO0, &receive_message)`：接收CAN消息
12. `*id = receive_message.rx_sfid`：获取CAN标准帧ID
13. `*len = receive_message.rx_dlen`：获取CAN数据长度
14. `data[i] = receive_message.rx_data[i]`：获取CAN数据