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/*********************************************************************

 *

 *                  CAN driver

 *

 *********************************************************************

 * FileName:        CAN.c

 *

 * Author               Date    Comment

 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 * Johan Böhlin     21-10-06    Original        (Rev 1.0)

 ********************************************************************/

#include <CANdefs.h>

#include <stackTasks.h>

#include <CAN.h>

static void canGetPacket(void);

#ifdef USE_CAN

/*

*   Function: canInit

*

*   Input:  none

*   Output: none

*   Pre-conditions: none

*   Affects: Changes can registers.

*   Depends: none.

*/

void canInit()

{

    CANCON = 0x80; //request config mode

    while ((CANSTAT & 0xE0) != 0x80 ); //wait for config mode request

    // BAUD AND TQS

    BRGCON1=0;

    // Sync_Seq = 2 x TQ = 1

    BRGCON1bits.SJW1=0;

    BRGCON1bits.SJW0=1;

    // Setting BRP.

    BRGCON1=BRGCON1|CAN_BRP;

    // Maximum PHEG1

    BRGCON2bits.SEG2PHTS = 1;

    // Phase_Seg1 = 2 x TQ = 1

    BRGCON2bits.SEG1PH2 = 0;

    BRGCON2bits.SEG1PH1 = 0;

    BRGCON2bits.SEG1PH0 = 1;

    // Prop_Seq = 2 x TQ = 1

    BRGCON2bits.PRSEG2 = 0;

    BRGCON2bits.PRSEG1 = 0;

    BRGCON2bits.PRSEG0 = 1;

    //  Enableing bus wake-up

    BRGCON3bits.WAKDIS = 0;

    // Dont use filter when wakeup

    BRGCON3bits.WAKFIL = 0;

    // Phase_Seg2 = 2 x TQ = 1

    BRGCON3bits.SEG2PH2 = 0;

    BRGCON3bits.SEG2PH1 = 0;

    BRGCON3bits.SEG2PH0 = 1;

    ECANCON=0;

    ECANCONbits.MDSEL1 = 0;

    ECANCONbits.MDSEL0 = 1;

    // FILTERS AND MASKS

    RXB0CONbits.RXM1=1;

    RXB0CONbits.RXM0=0;

    // INTERRUPTS

    // Diable transmit interrupt

    TXBIE = 0;

    //rx any interrupt

    PIR3 = 0;

    PIE3 = 0b00000011;

    // High interrupt

    IPR3 =0b00000011;

    // Programmable buffers interrupt

    BIE0  = 0xFF;  

    //loopback mode or not

    #ifdef CAN_LOOPBACK_MODE

        CANCON = 0x40;//request loopback mode

        while ((CANSTAT & 0xE0) != 0x40 );//wait for loopback mode

    #else

        CANCON = 0x00;//request normal mode

        while ((CANSTAT & 0xE0) != 0x00 );//wait for normal mode

    #endif

}

/*

*   Function: canISR

*

*   Input:  none

*   Output: none

*   Pre-conditions: a call to canInit()

*   Affects: interrupt registers and receive data buffers

*   Depends: ..

*/

void canISR()

{

    if (PIR3bits.RXBnIF || PIR3bits.RXB1IF || PIR3bits.RXB0IF)

    {

        // Get which buffer that is ful.

             if (RXB0CONbits.RXFUL) { ECANCON=(ECANCON&0b00000)|0b10000; canGetPacket(); }

        else if (RXB1CONbits.RXFUL) { ECANCON=(ECANCON&0b00000)|0b10001; canGetPacket(); }

        else if (B0CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10010; canGetPacket(); }

        else if (B1CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10011; canGetPacket(); }

        else if (B2CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10100; canGetPacket(); }

        else if (B3CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10101; canGetPacket(); }

        else if (B4CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10110; canGetPacket(); }

        else if (B5CONbits.RXFUL)   { ECANCON=(ECANCON&0b00000)|0b10111; canGetPacket(); }

        if (PIR3bits.RXBnIF) {PIR3bits.RXBnIF = 0;}

        if (PIR3bits.RXB1IF) {PIR3bits.RXB1IF = 0;}

        if (PIR3bits.RXB0IF) {PIR3bits.RXB0IF = 0;}

    }

}

/*

*   Function: canGetPacket

*

*   Input:  none

*   Output: none

*   Pre-conditions: a call to canISR and an packet is available and banked to RXB0

*   Affects: Calls canParse() function in main for parsing received packet.

*   Depends: none.

*/

void canGetPacket()

{

        CAN_MESSAGE cm;

        // Set extended mode or not.

        cm.extended=(RXB0SIDLbits.EXID==0?FALSE:TRUE);

        // Clear

        cm.ident=0;

        if (cm.extended==TRUE)

        {

            //Read extended ident.

            //xx xx xx 28 27 26 25 24   23 22 21 20 19 18 17 16   15 14 13 12 11 10 09 08   07 06 05 04 03 02 01 00

            //RXB0SIDH 28 27 26 25 24 23 22 21

            //RXB0SIDL 20 19 18 xx xx xx 17 16

            //RXB0EIDH 15 14 13 12 11 10 09 08

            //RXB0EIDL 07 06 05 04 03 02 01 00

            cm.ident = (((DWORD)RXB0SIDH)<<21) + (((DWORD)(RXB0SIDL & 0xE0))<<13) + (((DWORD)(RXB0SIDL & 0x03))<<16) + (((DWORD)RXB0EIDH)<<8) + (BYTE)RXB0EIDL;

        }

        else

        {

            //Read standard ident.

            //xx xx xx xx xx 10 09 08   07 06 05 04 03 02 01 00

            //RXB0SIDH 10 09 08 07 06 05 04 03

            //RXB0SIDL 02 01 00 xx xx xx xx xx

            cm.ident = (((DWORD)RXB0SIDH)<<3) + (((DWORD)RXB0SIDL)>>5);

        }

        // Data length

        cm.data_length=(RXB0DLCbits.DLC3<<3)+(RXB0DLCbits.DLC2<<2)+(RXB0DLCbits.DLC1<<1)+RXB0DLCbits.DLC0;

        // Remote request

        cm.remote_request=(RXB0DLCbits.RXRTR==0?FALSE:TRUE);

        // Data one bye one, for speed

        cm.data[0]=RXB0D0;  cm.data[1]=RXB0D1;

        cm.data[2]=RXB0D2;  cm.data[3]=RXB0D3;

        cm.data[4]=RXB0D4;  cm.data[5]=RXB0D5;

        cm.data[6]=RXB0D6;  cm.data[7]=RXB0D7;

        // Clear ful status

        RXB0CONbits.RXFUL=0;

        //Call main parser

        canParse(cm);

}

/*

*   Function: canSendMessage

*

*   Input:  CAN_MESSAGE to send

*   Output: True if packet scheduled sucess, false otherwise.

*   Pre-conditions: canInit

*   Affects: ..

*   Depends: ..

*/

BOOL canSendMessage(CAN_MESSAGE cm,CAN_PRIORITY prio)

{

    if ( TXB0CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00011; }

    if ( TXB1CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00100; }

    if ( TXB2CONbits.TXREQ == 0 )  { ECANCON=(ECANCON&0b00000)|0b00101; }

    // None of the transmit buffers were empty. 

    else { return FALSE;}

    if (prio<0 || prio>3) prio = 0;

        if (cm.extended==TRUE)

        {

            //Write extended ident.

            //xx xx xx 28 27 26 25 24   23 22 21 20 19 18 17 16   15 14 13 12 11 10 09 08   07 06 05 04 03 02 01 00

            //RXB0SIDH 28 27 26 25 24 23 22 21

            //RXB0SIDL 20 19 18 xx xx xx 17 16

            //RXB0EIDH 15 14 13 12 11 10 09 08

            //RXB0EIDL 07 06 05 04 03 02 01 00

            RXB0SIDH =  (BYTE)((cm.ident>>21));

            RXB0SIDL = ((BYTE)(cm.ident>>16) & 0x03) + ((BYTE)(cm.ident>>13) & 0xE0);

            RXB0EIDH =  (BYTE)(cm.ident>>8);

            RXB0EIDL =  (BYTE)cm.ident;

        }

        else

        {

            //Write standard ident.

            //xx xx xx xx xx 10 09 08   07 06 05 04 03 02 01 00

            //RXB0SIDH 10 09 08 07 06 05 04 03

            //RXB0SIDL 02 01 00 xx xx xx xx xx

            RXB0SIDH=  (BYTE)(cm.ident>>3);

            RXB0SIDL= ((BYTE)(cm.ident<<5) & 0xE0);

        }

        // Data length

        RXB0DLC = 0;

        if (cm.data_length>8) RXB0DLC=8; else RXB0DLC=cm.data_length;

        // Remote request

        if (cm.remote_request==TRUE)

        {

            _asm

                bsf RXB0DLC, 6, 0

            _endasm

        }

        else

        {

            _asm

                bcf RXB0DLC, 6, 0

            _endasm

        }

        // Data one bye one, for speed

        RXB0D0=cm.data[0];  RXB0D1=cm.data[1];

        RXB0D2=cm.data[2];  RXB0D3=cm.data[3];

        RXB0D4=cm.data[4];  RXB0D5=cm.data[5];

        RXB0D6=cm.data[6];  RXB0D7=cm.data[7];

        // set extended or not

        RXB0SIDLbits.EXID=(cm.extended==TRUE?1:0);

        // Priority

        RXB0CON = (RXB0CON & 0b11111100) | prio;

        // mark as redy to transmit

        _asm

            bsf RXB0CON, 3, 0

        _endasm

        return TRUE;

}

#endif //USE_CAN