AT90CAN128的CAN编程

末蓝、 2022-08-25 08:30 139阅读 0赞

这几天一直在忙活 AT90CAN128的CAN编程，几天终于有眉目了。其实他的can用起来不复杂，只是一开始没有仔细看手册，走了不少弯路。

编译器ICCAVR

4M晶振

50K波特率

void can\_init(void)  
\{  
    // CAN Controller initialization  
    // CAN Controller initialization

// CAN System Clock: 400.0 kHz  
    CANBT1=0x12;  
    // Propagation Time Segement: 7.500 us  
    // Re-Sync Jump Width: 2.500 us  
    CANBT2=0x04;  
    // Sample Point(s): 3  
    // Phase Segment 1: 5.000 us  
    // Phase Segment 2: 5.000 us  
    CANBT3=0x13;  
    // CAN Timer Clock Period: 2.000 us  
    CANTCON=0x00;

//--------------can\_MOB INITIAL-------------------  
    //MOB0=RX  
    CANPAGE  = 0x00;                                                              //MOB0,自动增量，初值为0  
    CANSTMOB = 0;  
    CANCDMOB = 0x80;  // RX                                                       //can2a,DLC=8  
    CANIDT4 = 0x00;                                                               //  
    CANIDT3 = 0x00;                                                               //  
    CANIDT2 = 0x00;                                                               //  
    CANIDT1 = 0x00;                                                               //

CANIDM4  = 0x00;                                                              //                             11111 100  
    CANIDM3  = 0x00;                                                              //                             11111 111  
    CANIDM2  = 0x00;                                                              //                             11111 111  
    CANIDM1  = 0x00;                                                              //CANIDM4-1数据校验屏蔽寄存器  00000 111

//MOB1=TX  
    CANPAGE = 0x10;  
    CANSTMOB = (1<<6);  //txok  
    CANCDMOB = 0x08;  
    CANIDT4 = 0x00;                                                               //  
    CANIDT3 = 0x00;                                                               //  
    CANIDT2 = 0xe0;                                                               //  
    CANIDT1 = 0x00;                                                               //

// CAN Interrupts:  
    // Timer Overrun: Off  
    // General Errors: Off  
    // Frame Buffer: Off  
    // MOb Errors: Off  
    // Transmit: Off  
    // Receive: Off  
    // Bus Off: Off  
    // All, except Timer Overrun: On  
    CANGIE=0xf0;  
    // MOb0: Enabled, MOb1: Enabled, MOb2: Disabled, MOb3: Disabled, MOb4: Disabled, MOb5: Disabled, MOb6: Disabled, MOb7: Disabled  
    CANEN2=0xff;  
    // MOb8: Disabled, MOb9: Disabled, MOb10: Disabled, MOb11: Disabled, MOb12: Disabled, MOb13: Disabled, MOb14: Disabled  
    CANEN1=0xff;  
    // MOb0..7 Interrupts: MOb0: On, MOb1: On, MOb2: Off, MOb3: Off, MOb4: Off, MOb5: Off, MOb6: Off, MOb7: Off  
    CANIE2=0x03;  
    // MOb8..14 Interrupts: MOb8: Off, MOb9: Off, MOb10: Off, MOb11: Off, MOb12: Off, MOb13: Off, MOb14: Off  
    CANIE1=0x00;  
    // Highest Interrupt Priority: MOb0  
    CANHPMOB=0x00;

CANGCON |= 0x02;      //CAN控制器启动

// CAN interrupt service routine  
\#pragma interrupt\_handler can\_isr:19  
void can\_isr(void)  
\{  
    // Place your code here  
    unsigned char i, flag;

CANGIE &= ~(1<<ENRX);                  //关接收中断\*\*\*\*  
    LED\_RUN(ON);  
    flag = CANSIT2;  
    //-----------------------------------------------------  
    if (flag & (1<<0))  
    \{  
        CANPAGE = 0<<4;  
        for(i = 0; i < 8; i++)  
        \{  
            data\_buf\[i\]=CANMSG;           //取得8个字节的数据  
        \}  
        CANPAGE = 0<<4;  
        CANSTMOB &= ~(1<<RXOK);                //清中断标志\*\*\*\*  
        CANCDMOB = 0x80;                       //接收使能  
    \}  
    if (flag & (1<<1))  
    \{  
        CANPAGE = 1<<4;  
        CANSTMOB &= ~(1<<TXOK);                //清中断标志\*\*\*\*  
    \}  
    //------------------------------------------------------  
    LED\_RUN(OFF);  
    CANGIE |=(1<<ENRX);  
\}

void can\_send (unsigned char n)  
\{  
    unsigned char i;

CANGIE &= ~(1<<ENRX);

CANPAGE = (n<<4);                              //MOB\_n, auto increment, index 0  
    if (CANSTMOB & (1<<TXOK))  
    \{  
        CANSTMOB &= ~(1<<TXOK);

for(i = 0; i < 8; i++)  
        \{  
            CANMSG = data\_buf\[i\];  
        \}  
        CANCDMOB = 0x48;  
    \}

CANGIE |=(1<<ENRX);  
\}