Custom_FIFO 结构在 user_define.h 中定义。这也显示在 图 2-5 中。

typedef struct {
    uint16_t fifo_in;
    uint16_t fifo_out;
    uint16_t fifo_count;
    Custom_Element *fifo_pointer;
} Custom_FIFO;

gCan2Uart_FIFO 和 gUart2Can_FIFO 在 main.c 中定义请注意 SRAM 的使用情况，该使用情况与 C2U_FIFO_SIZE、U2C_FIFO_SIZE 和 Custom_Element 的大小相关。

/* Variables for C2U_FIFO
 * C2U_FIFO is used to temporarily store message from CAN to UART */
Custom_Element gC2U_FIFO[C2U_FIFO_SIZE];
Custom_FIFO gCan2Uart_FIFO = {0, 0, 0, gC2U_FIFO};

/* Variables for U2C_FIFO
 * U2C_FIFO is used to temporarily store message from UART to CAN */
Custom_Element gU2C_FIFO[U2C_FIFO_SIZE];
Custom_FIFO gUart2Can_FIFO = {0, 0, 0, gU2C_FIFO};