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

 *

 *                  CAN module

 *

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

 * FileName:        $HeadURL: https://svn.auml.se/svn/HomeAutomation/trunk/EmbeddedSoftware/PIC/canBase/Source/CAN.c $

 * Last changed:    $LastChangedDate: 2006-11-14 21:11:28 +0100 (Tue, 14 Nov 2006) $

 * By:              $LastChangedBy: johboh $

 * Revision:        $Revision: 95 $

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

#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 = 1; // 0  For mode 1 

    ECANCONbits.MDSEL0 = 0; // 1  For mode 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)

    {

        ECANCON=(ECANCON&0b00000)|(0b10000|(CANCON&0x0F));

        if (RXB0CONbits.RXFUL) canGetPacket();

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

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

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

    }

}

/*

*   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;

        //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

        //funct xx xx xx xx 28 27 26 25

        //funcc xx xx xx xx xx xx 24 23 22 21 20 19 18 17 16 15 

        //nid   xx xx 14 13 12 11 10 09 

        //sid   xx xx xx xx xx xx xx 08 07 06 05 04 03 02 01 00

        cm.funct=((RXB0SIDH & 0xF0)>>4);

        cm.funcc=(((WORD)(RXB0SIDH & 0x0F))<<6)+(((WORD)(RXB0SIDL & 0xE0))>>2)+(((WORD)(RXB0SIDL & 0x03))<<1)+(((WORD)(RXB0EIDH & 0x80))>>7);

        cm.nid=((RXB0EIDH & 0x7E)>>1);

        cm.sid=(((WORD)(RXB0EIDH & 0x01))<<8)+RXB0EIDL;

        // Data length

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

        // 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;

        //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

        //funct xx xx xx xx 28 27 26 25

        //funcc xx xx xx xx xx xx 24 23 22 21 20 19 18 17 16 15 

        //nid   xx xx 14 13 12 11 10 09 

        //sid   xx xx xx xx xx xx xx 08 07 06 05 04 03 02 01 00

        RXB0SIDH = (BYTE)((cm.funct & 0x0F)<<4)+(BYTE)((cm.funcc & 0x03C0)>>6);

        RXB0SIDL = (BYTE)((cm.funcc & 0x003F)<<2)+(BYTE)((cm.funcc & 0x0006)>>1);

        RXB0EIDH = (BYTE)((cm.funcc & 0x0001)<<7)+(BYTE)((cm.nid & 0x3F)<<1)+(BYTE)((cm.sid & 0x0100)>>8);

        RXB0EIDL = (BYTE)((cm.sid & 0x00FF));

        // Data length

        RXB0DLC = 0;

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

        // NOT Remote request

        _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

        RXB0SIDLbits.EXID=1;

        // Priority

        RXB0CON = (RXB0CON & 0b11111100) | prio;

        // mark as redy to transmit

        _asm

            bsf RXB0CON, 3, 0

        _endasm

        return TRUE;

}

#endif //USE_CAN