文章目录[隐藏]

1、区别

2807x、28004x芯片的CAN通讯模块与28335、28067芯片模块配置有很大区别，

28004x

官方例程只有库函数，

没有直接配置寄存器写法

2806x

例程有直接操作寄存器

2、28004x的CAN配置步骤

需参考 C2000Ware_DigitalPower_SDK_3_02_00_00\c2000ware\driverlib\f28004x\examples\can 和

C2000Ware_DigitalPower_SDK_3_02_00_00\c2000ware\driverlib\f28004x\driverlib路径的文件

can.c -can编写的函数

can.h -相关宏定义声明

hw_can.h -物理偏移地址


    //1、 配置CAN的GPIO引脚
    // Initialize GPIO and configure GPIO pins for CANTX/CANRX
    // on module A and B
    //
    Device_initGPIO();
    GPIO_setPinConfig(DEVICE_GPIO_CFG_CANRXA);
    GPIO_setPinConfig(DEVICE_GPIO_CFG_CANTXA);
    GPIO_setPinConfig(DEVICE_GPIO_CFG_CANRXB);
 GPIO_setPinConfig(DEVICE_GPIO_CFG_CANTXB);
    
//2、初始化CAN模块
    // Initialize the CAN controllers
    //
    CAN_initModule(CANA_BASE);
CAN_initModule(CANB_BASE);

    //3、配置CAN波特率
    // Set up the CAN bus bit rate to 500kHz for each module
    // Refer to the Driver Library User Guide for information on how to set
    // tighter timing control. Additionally, consult the device data sheet
    // for more information about the CAN module clocking.
    //
    CAN_setBitRate(CANA_BASE, DEVICE_SYSCLK_FREQ, 500000, 20);
CAN_setBitRate(CANB_BASE, DEVICE_SYSCLK_FREQ, 500000, 20);

    //4、使能CAN_INT_IE0、CAN_INT_ERROR、CAN_INT_STATUS中断
    // Enable interrupts on the CAN B peripheral.
    //
    CAN_enableInterrupt(CANB_BASE, CAN_INT_IE0 | CAN_INT_ERROR |
                        CAN_INT_STATUS);
    //5、配置canbISR中断函数映射表入口
    // Interrupts that are used in this example are re-mapped to
    // ISR functions found within this file.
    // This registers the interrupt handler in PIE vector table.
    //
    Interrupt_register(INT_CANB0, &canbISR);

    //
    // Enable the CAN-B interrupt signal
    //使能对应的IER （INT_CANB0对应为9.7）
Interrupt_enable(INT_CANB0);  
//使能can模块的全局中断
CAN_enableGlobalInterrupt(CANB_BASE, CAN_GLOBAL_INT_CANINT0);

// 对应的32个邮箱可配置为发送或接收邮箱、标准帧或扩展帧模式、邮箱ID号、数据长度
    // Initialize the transmit message object used for sending CAN messages.
    // Message Object Parameters:
    //      CAN Module: A
    //      Message Object ID Number: 1
    //      Message Identifier: 0x95555555
    //      Message Frame: Extended
    //      Message Type: Transmit
    //      Message ID Mask: 0x0
    //      Message Object Flags: None
    //      Message Data Length: 4 Bytes
    //
    CAN_setupMessageObject(CANA_BASE, TX_MSG_OBJ_ID, 0x95555555,
                           CAN_MSG_FRAME_EXT, CAN_MSG_OBJ_TYPE_TX, 0,
                           CAN_MSG_OBJ_NO_FLAGS, MSG_DATA_LENGTH);

    //
    // Initialize the receive message object used for receiving CAN messages.
    // Message Object Parameters:
    //      CAN Module: B
    //      Message Object ID Number: 1
    //      Message Identifier: 0x95555555
    //      Message Frame: Extended
    //      Message Type: Receive
    //      Message ID Mask: 0x0
    //      Message Object Flags: Receive Interrupt
    //      Message Data Length: 4 Bytes
    //
    CAN_setupMessageObject(CANB_BASE, RX_MSG_OBJ_ID, 0x95555555,
                           CAN_MSG_FRAME_EXT, CAN_MSG_OBJ_TYPE_RX, 0,
                           CAN_MSG_OBJ_RX_INT_ENABLE, MSG_DATA_LENGTH);

3、28004x的CAN中断接收及CAN总线异常中断

通过下面语句知道，使能CAN_INT_IE0、CAN_INT_ERROR、CAN_INT_STATUS中断

CAN_enableInterrupt(CANB_BASE, CAN_INT_IE0 | CAN_INT_ERROR |

CAN_INT_STATUS);

__interrupt void
canbISR(void)
{
    uint32_t status;

    //
    // Read the CAN-B interrupt status to find the cause of the interrupt
    //
    status = CAN_getInterruptCause(CANB_BASE);

    //
    // If the cause is a controller status interrupt, then get the status
    //
    if(status == CAN_INT_INT0ID_STATUS)
    {
        //
        // Read the controller status.  This will return a field of status
        // error bits that can indicate various errors.  Error processing
        // is not done in this example for simplicity.  Refer to the
        // API documentation for details about the error status bits.
        // The act of reading this status will clear the interrupt.
        //
        status = CAN_getStatus(CANB_BASE);

        //
        // Check to see if an error occurred.
        //
        if(((status  & ~(CAN_STATUS_RXOK)) != CAN_STATUS_LEC_MSK) &&
           ((status  & ~(CAN_STATUS_RXOK)) != CAN_STATUS_LEC_NONE))
        {
            //
            // Set a flag to indicate some errors may have occurred.
            //
            errorFlag = 1;
        }
    }
    //
    // Check if the cause is the CAN-B receive message object 1
    //
    else if(status == RX_MSG_OBJ_ID)
    {
        //
        // Get the received message
        //
        CAN_readMessage(CANB_BASE, RX_MSG_OBJ_ID, rxMsgData);

        //
        // Getting to this point means that the RX interrupt occurred on
        // message object 1, and the message RX is complete.  Clear the
        // message object interrupt.
        //
        CAN_clearInterruptStatus(CANB_BASE, RX_MSG_OBJ_ID);

        //
        // Increment a counter to keep track of how many messages have been
        // received. In a real application this could be used to set flags to
        // indicate when a message is received.
        //
        rxMsgCount++;

        //
        // Since the message was received, clear any error flags.
        //
        errorFlag = 0;
    }
    //
    // If something unexpected caused the interrupt, this would handle it.
    //
    else
    {
        //
        // Spurious interrupt handling can go here.
        //
    }

    //
    // Clear the global interrupt flag for the CAN interrupt line
    //
    CAN_clearGlobalInterruptStatus(CANB_BASE, CAN_GLOBAL_INT_CANINT0);

    //
    // Acknowledge this interrupt located in group 9
    //
    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP9);
}

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