S32K144-EVB开发板CAN实例代码

以下是S32K144-EVB开发板CAN的示例代码，可以作为参考：

#include "board.h"
#include "fsl_debug_console.h"
#include "fsl_flexcan.h"

/*******************************************************************************
 * Definitions
 ******************************************************************************/
/* Define constants for FlexCAN baudrate calculation */
#define PCLK_FREQ (CLOCK_GetPllFreq(kCLOCK_SystemPll1Ctrl) / (CLOCK_GetRootPreDivider(kCLOCK_RootCan1)) / \
                   (CLOCK_GetRootPostDivider(kCLOCK_RootCan1)) / 2U)
#define FLEXCAN_EXAMPLE_FRAME_COUNT (1U)
#define EXAMPLE_FLEXCAN (CAN0)
#define EXAMPLE_CAN_CLK_FREQ (PCLK_FREQ)
#define EXAMPLE_CAN_IRQn CAN0_IRQn
#define EXAMPLE_CAN_IRQHandler CAN0_IRQHandler
#define EXAMPLE_FLEXCAN_DMA_IRQn DMA0_DMA16_IRQn
#define EXAMPLE_RX_MESSAGE_BUFFER_NUM (5U)
#define EXAMPLE_TX_MESSAGE_BUFFER_NUM (4U)
#define RX_MAILBOX_NUM (7U)
#define TX_MAILBOX_NUM (8U)
#define DLC (8U)

/*******************************************************************************
 * Prototypes
 ******************************************************************************/

/*******************************************************************************
 * Variables
 ******************************************************************************/

/* ESR register */
volatile uint32_t g_err_cnt = 0;
volatile uint32_t g_esr = 0;

/* CAN message buffer */
flexcan_mb_transfer_t rxXfer, txXfer;

/* Received data */
flexcan_frame_t rxFrames[EXAMPLE_FLEXCAN_FRAME_COUNT];

/* Remote request data */
flexcan_frame_t txRemoteFrame;

/*******************************************************************************
 * Code
 ******************************************************************************/

/*!
 * @brief FlexCAN user callback function.
 *
 * This function is called when FlexCAN receive a frame or finished a transfer.
 *
 * @param base FlexCAN peripheral base address.
 * @param handle Pointer to FlexCAN handle structure.
 * @param status FlexCAN transfer status.
 * @param userData User data.
 */
void FLEXCAN_UserCallback(CAN_Type *base, flexcan_handle_t *handle, status_t status, void *userData)
{
    switch (status)
    {
        /* Process FlexCAN Rx event. */
        case kStatus_FLEXCAN_RxIdle:
            PRINTF("Frame received successfully!\r\n");
            break;

        /* Process FlexCAN Tx event. */
        case kStatus_FLEXCAN_TxIdle:
            PRINTF("Frame transmitted successfully!\r\n");
            break;

        /* Process FlexCAN error event. */
        case kStatus_FLEXCAN_ErrorStatus:
            PRINTF("FlexCAN error happened: %#x!\r\n", handle->errorCode);
            break;

        default:
            break;
    }
}

/*!
 * @brief Main function.
 */
int main(void)
{
    flexcan_config_t flexcanConfig;
    flexcan_frame_t txFrame;
    flexcan_handle_t flexcanHandle;
    uint32_t i;

    /* Initialize board hardware. */
    BOARD_InitPins();
    BOARD_BootClockRUN();
    BOARD_InitDebugConsole();

    PRINTF("\r\nFlexCAN example -- Start.\r\n");

    /* Initialize FlexCAN module. */
    flexcanConfig.clkSrc = kFLEXCAN_ClkSrcPeri;
    flexcanConfig.baudRate = 125000U;
    flexcanConfig.enableLoopBack = false;
    flexcanConfig.enableSelfWakeup = false;
    flexcanConfig.enableIndividMask = false;
    flexcanConfig.maxMbNum = 16U;
    FLEXCAN_Init(EXAMPLE_FLEXCAN, &flexcanConfig, EXAMPLE_CAN_CLK_FREQ);

    /* Create FlexCAN handle structure and set call back function. */
    FLEXCAN_TransferCreateHandle(EXAMPLE_FLEXCAN, &flexcanHandle, FLEXCAN_UserCallback, NULL);

    /* Setup Rx Message Buffer. */
    rxXfer.frame = &rxFrames[0];
    rxXfer.mbIdx = RX_MAILBOX_NUM;
    FLEXCAN_SetRxMbConfig(EXAMPLE_FLEXCAN, rxXfer.mbIdx, true);

    /* Setup Tx Message Buffer. */
    txXfer.frame = &txFrame;
    txXfer.mbIdx = TX_MAILBOX_NUM;
    FLEXCAN_SetTxMbConfig(EXAMPLE_FLEXCAN, txXfer.mbIdx, true);

    /* Start receive data through polling mode. */
    rxXfer.frame = &rxFrames[0];
    rxXfer.mbIdx = RX_MAILBOX_NUM;

    /* Set up remote request data. */
    txRemoteFrame.format = kFLEXCAN_FrameFormatStandard;
    txRemoteFrame.type = kFLEXCAN_FrameTypeRemote;
    txRemoteFrame.id = FLEXCAN_ID_STD(0x123);
    txRemoteFrame.length = DLC;

    while (1)
    {
        /* Wait for receive data. */
        while (kStatus_FLEXCAN_RxIdle != FLEXCAN_TransferReceiveNonBlocking(EXAMPLE_FLEXCAN, &flexcanHandle, &rxXfer))
        {
        }

        /* Copy remote request data to Tx Message Buffer. */
        for (i = 0; i < DLC; i++)
        {
            txFrame.dataByte[i] = txRemoteFrame.dataByte[i];
        }
        txFrame.format = kFLEXCAN_FrameFormatStandard;
        txFrame.type = kFLEXCAN_FrameTypeData;
        txFrame.id = FLEXCAN_ID_STD(0x321);
        txFrame.length = DLC;

        /* Wait until previous FlexCAN transfer finished. */
        while (kStatus_FLEXCAN_TxIdle != FLEXCAN_GetTransferStatusFlags(EXAMPLE_FLEXCAN, txXfer.mbIdx))
        {
        }

        /* Transmit remote request frame. */
        FLEXCAN_TransferSendNonBlocking(EXAMPLE_FLEXCAN, &flexcanHandle, &txXfer);

        /* Wait until transfer finished. */
        while (kStatus_FLEXCAN_TxIdle != FLEXCAN_GetTransferStatusFlags(EXAMPLE_FLEXCAN, txXfer.mbIdx))
        {
        }
    }
}

这个示例程序演示了如何使用S32K144-EVB开发板上CAN模块。在这个例子中，我们使用了两个邮箱，其中一个用于接收数据，另一个用于发送数据。在主函数中，我们使用了一个 while 循环，不断地等待接收数据，并且发送一条远程请求帧作为响应。可以根据自己的需求进行修改。