1. 创建一个新的32位MCU工程

/* CAN message storage buffer definition */
uint8_t Can1MessageRAM[CAN1_MESSAGE_RAM_CONFIG_SIZE] __attribute__((aligned (32)));

/* Standard identifier id[28:18]*/
#define WRITE_ID(id) (id << 18)
#define READ_ID(id)  (id >> 18)

//static uint8_t g_txFiFo[MCAN1_TX_FIFO_BUFFER_SIZE]; /* CAN TX message buffer */
static uint8_t g_rxFiFo0[CAN1_RX_FIFO0_SIZE];      /* CAN FIFO 0 RX buffer */
static uint8_t g_rxFiFo1[CAN1_RX_FIFO1_SIZE];      /* CAN FIFO 1 RX buffer */

static volatile bool    g_txdone  = false;         /* CAN TX completion flag */
static volatile bool    g_rx0done = false;         /* FIFO 0 got new message */
static volatile bool    g_rx1done = false;         /* FIFO 1 got new message */
static volatile uint8_t g_rxnum0 = 0;              /* FIFO 0 new message number */
static volatile uint8_t g_rxnum1 = 0;              /* FIFO 0 new message number */

static void CAN1_TXFIFO_Txdone(uintptr_t contextHandle)
{
    g_txdone = true;
}

static void CAN1_RXFIFO0_Rxdone(uint8_t numberOfMessage, uintptr_t contextHandle)
{
    g_rx0done = true;
    g_rxnum0  = numberOfMessage;
}

static void CAN1_RXFIFO1_Rxdone(uint8_t numberOfMessage, uintptr_t contextHandle)
{
    g_rx1done = true;
    g_rxnum1  = numberOfMessage;
}

static inline void CAN1_Demo_Initialization(void)
{
    GPIO_PC13_Clear();
    CAN1_TxFifoCallbackRegister(CAN1_TXFIFO_Txdone, 0);
    CAN1_RxFifoCallbackRegister(CAN_RX_FIFO_0, CAN1_RXFIFO0_Rxdone, 0);
    CAN1_RxFifoCallbackRegister(CAN_RX_FIFO_1, CAN1_RXFIFO1_Rxdone, 0);
}

/* Print Rx Message */
static void print_message(CAN_RX_FIFO_NUM fifonum, uint8_t numberOfMessage, 
                          CAN_RX_BUFFER *rxBuf, uint8_t rxBufLen)
{
    uint8_t msgLength = 0;
    uint32_t id = 0;

    for (uint8_t count = 0; count < numberOfMessage; count++)
    {
        /* Print message to Console */
        printf(" Rx FIFO%d: ", 
                fifonum == CAN_RX_FIFO_0 ? 0:1);
        id = rxBuf->xtd ? rxBuf->id : READ_ID(rxBuf->id);
        msgLength = rxBuf->dlc;
        printf(" Message - ID=0x%x Length=%d\r\n", (unsigned int)id, (unsigned int)msgLength);
        rxBuf += rxBufLen;
    }
}

int main ( void )
{
    uint8_t rx_num;
    
    /* Initialize all modules */
    SYS_Initialize ( NULL );

    printf(" ------------------------------ \r\n");
    printf("            CAN Demo            \r\n");
    printf(" ------------------------------ \r\n");
    
    /* Set Message RAM Configuration */
    CAN1_MessageRAMConfigSet(Can1MessageRAM);
    
    CAN1_Demo_Initialization();
    
    while ( true )
    {
        /* Maintain state machines of all polled MPLAB Harmony modules. */
        SYS_Tasks ( );

        if (g_rx0done)
        {
            __disable_irq();
            g_rx0done = false;
            rx_num    = g_rxnum0;
            __enable_irq();
            
            memset(g_rxFiFo0, 0x00, (rx_num * CAN1_RX_FIFO0_ELEMENT_SIZE));
            if (CAN1_MessageReceiveFifo(CAN_RX_FIFO_0, rx_num, 
                                        (CAN_RX_BUFFER *)g_rxFiFo0) == true)
            {
                print_message(CAN_RX_FIFO_0, rx_num, (CAN_RX_BUFFER *)g_rxFiFo0,
                              CAN1_RX_FIFO0_ELEMENT_SIZE);
            }
            else
            {
                printf(" Error in FIFO0 received message\r\n");
            }
        }
        
        if (g_rx1done)
        {
            __disable_irq();
            g_rx1done = false;
            rx_num    = g_rxnum1;
            __enable_irq();
            
            memset(g_rxFiFo1, 0x00, (rx_num * CAN1_RX_FIFO1_ELEMENT_SIZE));
            if (CAN1_MessageReceiveFifo(CAN_RX_FIFO_1, rx_num, (CAN_RX_BUFFER *)g_rxFiFo1) == true)
            {
                print_message(CAN_RX_FIFO_1, rx_num, (CAN_RX_BUFFER *)g_rxFiFo1,
                              CAN1_RX_FIFO1_ELEMENT_SIZE);
            }
            else
            {
                printf(" Error in FIFO1 received message\r\n");
            }
        }
    }

    /* Execution should not come here during normal operation */

    return ( EXIT_FAILURE );
}