AMiRo-OS

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

* \file         Source\ARMCM4_STM32\can.c

* \brief        Bootloader CAN communication interface source file.

* \ingroup      Target_ARMCM4_STM32

* \internal

*----------------------------------------------------------------------------------------

*                          C O P Y R I G H T

*----------------------------------------------------------------------------------------

*   Copyright (c) 2013  by Feaser    http://www.feaser.com    All rights reserved

*

*----------------------------------------------------------------------------------------

*                            L I C E N S E

*----------------------------------------------------------------------------------------

* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or

* modify it under the terms of the GNU General Public License as published by the Free

* Software Foundation, either version 3 of the License, or (at your option) any later

* version.

*

* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR

* PURPOSE. See the GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License along with OpenBLT.

* If not, see <http://www.gnu.org/licenses/>.

*

* A special exception to the GPL is included to allow you to distribute a combined work

* that includes OpenBLT without being obliged to provide the source code for any

* proprietary components. The exception text is included at the bottom of the license

* file <license.html>.

*

* \endinternal

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

#define CAN_DEBUG       (0)

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

* Include files

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

#include "boot.h"                                /* bootloader generic header          */

#if (CAN_DEBUG > 0)

#include <helper.h>

#endif

#if (BOOT_COM_CAN_ENABLE > 0 || BOOT_GATE_CAN_ENABLE > 0)

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

* Type definitions

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

/** \brief CAN transmission mailbox layout. */

typedef struct

{

  volatile blt_int32u TIR;

  volatile blt_int32u TDTR;

  volatile blt_int32u TDLR;

  volatile blt_int32u TDHR;

} tCanTxMailBox;

/** \brief CAN reception FIFO mailbox layout. */

typedef struct

{

  volatile blt_int32u RIR;

  volatile blt_int32u RDTR;

  volatile blt_int32u RDLR;

  volatile blt_int32u RDHR;

} tCanRxFIFOMailBox;

/** \brief CAN filter register layout. */

typedef struct

{

  volatile blt_int32u FR1;

  volatile blt_int32u FR2;

} tCanFilter;

/** \brief CAN controller register layout. */

typedef struct

{

  volatile blt_int32u MCR;

  volatile blt_int32u MSR;

  volatile blt_int32u TSR;

  volatile blt_int32u RF0R;

  volatile blt_int32u RF1R;

  volatile blt_int32u IER;

  volatile blt_int32u ESR;

  volatile blt_int32u BTR;

  blt_int32u          RESERVED0[88];

  tCanTxMailBox       sTxMailBox[3];

  tCanRxFIFOMailBox   sFIFOMailBox[2];

  blt_int32u          RESERVED1[12];

  volatile blt_int32u FMR;

  volatile blt_int32u FM1R;

  blt_int32u          RESERVED2;

  volatile blt_int32u FS1R;

  blt_int32u          RESERVED3;

  volatile blt_int32u FFA1R;

  blt_int32u          RESERVED4;

  volatile blt_int32u FA1R;

  blt_int32u          RESERVED5[8];

  tCanFilter          sFilterRegister[28];

} tCanRegs;

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

* Macro definitions

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

/** \brief Reset request bit. */

#define CAN_BIT_RESET    ((blt_int32u)0x00008000)

/** \brief Initialization request bit. */

#define CAN_BIT_INRQ     ((blt_int32u)0x00000001)

/** \brief Initialization acknowledge bit. */

#define CAN_BIT_INAK     ((blt_int32u)0x00000001)

/** \brief Sleep mode request bit. */

#define CAN_BIT_SLEEP    ((blt_int32u)0x00000002)

/** \brief Filter 0 selection bit. */

#define CAN_BIT_FILTER0  ((blt_int32u)0x00000001)

/** \brief Filter 14 selection bit. */

#define CAN_BIT_FILTER14 ((blt_int32u)0x00004000)

/** \brief Filter init mode bit. */

#define CAN_BIT_FINIT    ((blt_int32u)0x00000001)

/** \brief Transmit mailbox 0 empty bit. */

#define CAN_BIT_TME0     ((blt_int32u)0x04000000)

/** \brief Transmit mailbox request bit. */

#define CAN_BIT_TXRQ     ((blt_int32u)0x00000001)

/** \brief Release FIFO 0 mailbox bit. */

#define CAN_BIT_RFOM0    ((blt_int32u)0x00000020)

#if (BOOT_GATE_CAN_ENABLE > 0)

blt_bool commandSend;

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

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

* Register definitions

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

#if (BOOT_COM_CAN_CHANNEL_INDEX == 0)

/** \brief Macro for accessing CAN1 controller registers. */

#define CANx             ((tCanRegs *) (blt_int32u)0x40006400)

#else

/** \brief Macro for accessing CAN2 controller registers. */

#define CANx             ((tCanRegs *) (blt_int32u)0x40006800)

#endif

/** \brief Macro for accessing CAN1 controller registers. */

#define CAN1             ((tCanRegs *) (blt_int32u)0x40006400)

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

* Type definitions

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

/** \brief Structure type for grouping CAN bus timing related information. */

typedef struct t_can_bus_timing

{

  blt_int8u tseg1;                                    /**< CAN time segment 1          */

  blt_int8u tseg2;                                    /**< CAN time segment 2          */

} tCanBusTiming;

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

* Local constant declarations

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

/** \brief CAN bittiming table for dynamically calculating the bittiming settings.

 *  \details According to the CAN protocol 1 bit-time can be made up of between 8..25

 *           time quanta (TQ). The total TQ in a bit is SYNC + TSEG1 + TSEG2 with SYNC

 *           always being 1. The sample point is (SYNC + TSEG1) / (SYNC + TSEG1 + SEG2) *

 *           100%. This array contains possible and valid time quanta configurations with

 *           a sample point between 68..78%.

 */

static const tCanBusTiming canTiming[] =

{                       /*  TQ | TSEG1 | TSEG2 | SP  */

                        /* ------------------------- */

    {  5, 2 },          /*   8 |   5   |   2   | 75% */

    {  6, 2 },          /*   9 |   6   |   2   | 78% */

    {  6, 3 },          /*  10 |   6   |   3   | 70% */

    {  7, 3 },          /*  11 |   7   |   3   | 73% */

    {  8, 3 },          /*  12 |   8   |   3   | 75% */

    {  9, 3 },          /*  13 |   9   |   3   | 77% */

    {  9, 4 },          /*  14 |   9   |   4   | 71% */

    { 10, 4 },          /*  15 |  10   |   4   | 73% */

    { 11, 4 },          /*  16 |  11   |   4   | 75% */

    { 12, 4 },          /*  17 |  12   |   4   | 76% */

    { 12, 5 },          /*  18 |  12   |   5   | 72% */

    { 13, 5 },          /*  19 |  13   |   5   | 74% */

    { 14, 5 },          /*  20 |  14   |   5   | 75% */

    { 15, 5 },          /*  21 |  15   |   5   | 76% */

    { 15, 6 },          /*  22 |  15   |   6   | 73% */

    { 16, 6 },          /*  23 |  16   |   6   | 74% */

    { 16, 7 },          /*  24 |  16   |   7   | 71% */

    { 16, 8 }           /*  25 |  16   |   8   | 68% */

};

int counter = 0;

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

** \brief     Search algorithm to match the desired baudrate to a possible bus

**            timing configuration.

** \param     baud The desired baudrate in kbps. Valid values are 10..1000.

** \param     prescaler Pointer to where the value for the prescaler will be stored.

** \param     tseg1 Pointer to where the value for TSEG2 will be stored.

** \param     tseg2 Pointer to where the value for TSEG2 will be stored.

** \return    BLT_TRUE if the CAN bustiming register values were found, BLT_FALSE

**            otherwise.

**

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

static blt_bool CanGetSpeedConfig(blt_int16u baud, blt_int16u *prescaler,

                                  blt_int8u *tseg1, blt_int8u *tseg2)

{

  blt_int8u  cnt;

  /* loop through all possible time quanta configurations to find a match */

  for (cnt=0; cnt < sizeof(canTiming)/sizeof(canTiming[0]); cnt++)

  {

    if (((BOOT_CPU_SYSTEM_SPEED_KHZ/4) % (baud*(canTiming[cnt].tseg1+canTiming[cnt].tseg2+1))) == 0)

    {

      /* compute the prescaler that goes with this TQ configuration */

      *prescaler = (BOOT_CPU_SYSTEM_SPEED_KHZ/4)/(baud*(canTiming[cnt].tseg1+canTiming[cnt].tseg2+1));

      /* make sure the prescaler is valid */

      if ( (*prescaler > 0) && (*prescaler <= 1024) )

      {

        /* store the bustiming configuration */

        *tseg1 = canTiming[cnt].tseg1;

        *tseg2 = canTiming[cnt].tseg2;

        /* found a good bus timing configuration */

        return BLT_TRUE;

      }

    }

  }

  /* could not find a good bus timing configuration */

  return BLT_FALSE;

} /*** end of CanGetSpeedConfig ***/

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

** \brief     Initializes the CAN controller and synchronizes it to the CAN bus.

** \return    none.

**

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

void CanInit(void)

{

  blt_int16u prescaler;

  blt_int8u  tseg1, tseg2;

  blt_bool   result;

#if (BOOT_GATE_CAN_ENABLE > 0)

  commandSend = BLT_FALSE;

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

  /* the current implementation supports CAN1 and 2. throw an assertion error in case a

   * different CAN channel is configured.

   */

  ASSERT_CT((BOOT_COM_CAN_CHANNEL_INDEX == 0 || BOOT_COM_CAN_CHANNEL_INDEX == 1));

  /* obtain bittiming configuration information */

  result = CanGetSpeedConfig(BOOT_COM_CAN_BAUDRATE/1000, &prescaler, &tseg1, &tseg2);

  ASSERT_RT(result == BLT_TRUE);

  /* disable all can interrupt. this driver works in polling mode */

  CANx->IER = (blt_int32u)0;

  /* set request to reset the can controller */

  CANx->MCR |= CAN_BIT_RESET ;

  /* wait for acknowledge that the can controller was reset */

  while ((CANx->MCR & CAN_BIT_RESET) != 0)

  {

    /* keep the watchdog happy */

    CopService();

  }

  /* exit from sleep mode, which is the default mode after reset */

  CANx->MCR &= ~CAN_BIT_SLEEP;

  /* set request to enter initialisation mode */

  CANx->MCR |= CAN_BIT_INRQ ;

  /* wait for acknowledge that initialization mode was entered */

  while ((CANx->MSR & CAN_BIT_INAK) == 0)

  {

    /* keep the watchdog happy */

    CopService();

  }

  /* configure the bittming */

  CANx->BTR = (blt_int32u)((blt_int32u)(3) << 24) | \

              (blt_int32u)((blt_int32u)(tseg1 - 1) << 16) | \

              (blt_int32u)((blt_int32u)(tseg2 - 1) << 20) | \

              (blt_int32u)(prescaler - 1);

//  CANx->BTR = (blt_int32u)((blt_int32u)(tseg1 - 1) << 16) | \

              (blt_int32u)((blt_int32u)(tseg2 - 1) << 20) | \

              (blt_int32u)(prescaler - 1) | \

              (blt_int32u)(0x3 << 30);

//  CANx->BTR = (blt_int32u)((blt_int32u)(15) << 16) | \

              (blt_int32u)((blt_int32u)(3) << 20) | \

              (blt_int32u)((blt_int32u)(1) << 24) | \

              (blt_int32u)(1) | \

              (blt_int32u)(0x3 << 30);

  /* set request to leave initialisation mode */

  CANx->MCR &= ~CAN_BIT_INRQ;

  /* wait for acknowledge that initialization mode was exited */

  while ((CANx->MSR & CAN_BIT_INAK) != 0)

  {

    /* keep the watchdog happy */

    CopService();

  }

#if (BOOT_COM_CAN_CHANNEL_INDEX == 0)

  /* enter initialisation mode for the acceptance filter */

  CAN1->FMR |= CAN_BIT_FINIT;

  /* deactivate filter 0 */

  CAN1->FA1R &= ~CAN_BIT_FILTER0;

  /* 32-bit scale for the filter */

  CAN1->FS1R |= CAN_BIT_FILTER0;

  /* open up the acceptance filter to receive all messages */

  CAN1->sFilterRegister[0].FR1 = 0;

  CAN1->sFilterRegister[0].FR2 = 0;

  /* select id/mask mode for the filter */

  CAN1->FM1R &= ~CAN_BIT_FILTER0;

  /* FIFO 0 assignation for the filter */

  CAN1->FFA1R &= ~CAN_BIT_FILTER0;

  /* filter activation */

  CAN1->FA1R |= CAN_BIT_FILTER0;

  /* leave initialisation mode for the acceptance filter */

  CAN1->FMR &= ~CAN_BIT_FINIT;

#else

  /* enter initialisation mode for the acceptance filter */

  CAN1->FMR |= CAN_BIT_FINIT;

  /* deactivate filter 14 */

  CAN1->FA1R &= ~CAN_BIT_FILTER14;

  /* 32-bit scale for the filter */

  CAN1->FS1R |= CAN_BIT_FILTER14;

  /* open up the acceptance filter to receive all messages */

  CAN1->sFilterRegister[14].FR1 = 0;

  CAN1->sFilterRegister[14].FR2 = 0;

  /* select id/mask mode for the filter */

  CAN1->FM1R &= ~CAN_BIT_FILTER14;

  /* FIFO 0 assignation for the filter */

  CAN1->FFA1R &= ~CAN_BIT_FILTER14;

  /* filter activation */

  CAN1->FA1R |= CAN_BIT_FILTER14;

  /* leave initialisation mode for the acceptance filter */

  CAN1->FMR &= ~CAN_BIT_FINIT;

#endif

} /*** end of CanInit ***/

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

** \brief     Transmits a packet formatted for the communication interface.

** \param     data Pointer to byte array with data that it to be transmitted.

** \param     len  Number of bytes that are to be transmitted.

** \return    none.

**

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

void CanTransmitPacket(blt_int8u *data, blt_int8u len, blt_int32u deviceID)

{

  /* make sure that transmit mailbox 0 is available */

  ASSERT_RT((CANx->TSR&CAN_BIT_TME0) == CAN_BIT_TME0);

  blt_int32u address;

#if (BOOT_GATE_CAN_ENABLE > 0)

  if (deviceID == 0) {

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

    address = (blt_int32u)BOOT_COM_CAN_TX_MSG_ID;

#if (BOOT_GATE_CAN_ENABLE > 0)

    commandSend = BLT_FALSE;

  } else {

    address = (blt_int32u)BOOT_COM_CAN_RX_MSG_ID;

    commandSend = BLT_TRUE;

  }

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

  /* init variables */

  blt_int8u canData[8];

  blt_int8u restLen = len;

  blt_int8u canIdx = 0;

  blt_int32u ackMsgId;

  blt_int8u ackMsgLen;

  /* send the given package in 8 byte packages */

  while (restLen > 0) {

    /* build the message identifier */

    CANx->sTxMailBox[0].TIR &= CAN_BIT_TXRQ;

    CANx->sTxMailBox[0].TIR |= (address << 21);

    /* if this is the first transmission of this packet */

    if (restLen == len) {

      /* store the message date length code (DLC) */

      CANx->sTxMailBox[0].TDTR = (restLen > 4) ? 8 : restLen+1+4;

      /* store the device ID */

      canData[0] = (blt_int8u)(0xFF & (deviceID >> 0));

      canData[1] = (blt_int8u)(0xFF & (deviceID >> 8));

      canData[2] = (blt_int8u)(0xFF & (deviceID >> 16));

      canData[3] = (blt_int8u)(0xFF & (deviceID >> 24));

      /* store the remaining packet length */

      canData[4] = restLen;

      canIdx = 5;

    }

    /* if this is a succeeding transmission of this packet */

    else {

      /* store the message date length code (DLC) */

      CANx->sTxMailBox[0].TDTR = (restLen > 7) ? 8 : restLen+1;

      /* store the remaining packet length */

      canData[0] = restLen;

      canIdx = 1;

    }

    /* store the packet payload */

    while (restLen > 0 && canIdx < 8) {

      canData[canIdx] = data[len-restLen];

      canIdx++;

      restLen--;

    }

    /* fill rest with nulls */

    while (canIdx < 8) {

      canData[canIdx] = 0;

      canIdx++;

    }

    /* store the message data bytes */

    CANx->sTxMailBox[0].TDLR = (((blt_int32u)canData[3] << 24) | \

                                ((blt_int32u)canData[2] << 16) | \

                                ((blt_int32u)canData[1] <<  8) | \

                                ((blt_int32u)canData[0]));

    CANx->sTxMailBox[0].TDHR = (((blt_int32u)canData[7] << 24) | \

                                ((blt_int32u)canData[6] << 16) | \

                                ((blt_int32u)canData[5] <<  8) | \

                                ((blt_int32u)canData[4]));

    /* request the start of message transmission */

    CANx->sTxMailBox[0].TIR |= CAN_BIT_TXRQ;

    /* wait for transmit completion */

    while ((CANx->TSR&CAN_BIT_TME0) == 0)

    {

      /* keep the watchdog happy */

      CopService();

    }

    /* wait for the acknowledgement transmission */

    while ((CANx->RF0R&(blt_int32u)0x00000003) == 0) {

      /* keep the watchdog happy */

      CopService();

    }

    /* read out the message identifier, length and payload */

    ackMsgId = (blt_int32u)0x000007FF & (CANx->sFIFOMailBox[0].RIR >> 21);

    ackMsgLen = (blt_int8u)0x0F & CANx->sFIFOMailBox[0].RDTR;

    canData[0] = (blt_int8u)0xFF & CANx->sFIFOMailBox[0].RDLR;

    canData[1] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 8);

    canData[2] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 16);

    canData[3] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 24);

    canData[4] = (blt_int8u)0xFF & CANx->sFIFOMailBox[0].RDHR;

    canData[5] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 8);

    canData[6] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 16);

    canData[7] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 24);

#if (CAN_DEBUG > 0)

    /* verification:

     * - ID must be "address & BOOT_COM_CAN_MSG_ACK"

     * - length must be 1

     * - canData[0] must b equal to restLen

     */

    if (ackMsgId != (address | (blt_int32u)BOOT_COM_CAN_MSG_ACK) ||

        ackMsgLen != 1 ||

        canData[0] != restLen) {

      /* some error occurred */

      blinkSOS(1);

      msleep(500);

      visualizeData((blt_int8u*)&ackMsgId, 2, 1);

      msleep(500);

      visualizeByte(ackMsgLen, 1);

      msleep(500);

      visualizeByte(canData[0], 1);

      msleep(500);

      visualizeByte(restLen, 1);

      blinkSOSinf();

    }

#endif /* CAN_DEBUG > 0 */

    /* release FIFO0 */

    CANx->RF0R |= CAN_BIT_RFOM0;

    /* modify address so that receivers can filter */

    address |= (blt_int32u)BOOT_COM_CAN_MSG_SUBSEQUENT;

  }

} /*** end of CanTransmitSinglePacket ***/

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

** \brief     Transmits many packets formatted for the communication interface.

** \param     data Pointer to byte array with data that it to be transmitted.

** \param     len  Number of bytes that are to be transmitted.

** \return    none.

**

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

/*void CanTransmitPacket(blt_int8u *data, blt_int8u len, blt_int8u deviceID)

{

  static blt_int8u canPacketData[8];

  canPacketData[0] = len;

  blt_int8u restLength = len;

  while (restLength > 0) {

    blt_int8u canIdx = 0;

    if (restLength == len) {

      canIdx = 1;

    }

/*    while (restLength > 0 && canIdx < 8) {

      canPacketData[canIdx] = data[len-restLength];

      canIdx++;

      restLength--;

    }*/

/*    blt_int8u dataLength = 8;

    if (dataLength > restLength) {

      dataLength = restLength;

    }

    CpuMemCopy((blt_int32u)&canPacketData[1], (blt_int32u)&data[], toReceive);

    CanTransmitSinglePacket(canPacketData, canIdx, deviceID);

  }

} /*** end of CanTransmitPacket ***/

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

** \brief     Receives a communication interface packet if one is present.

** \param     data Pointer to byte array where the data is to be stored.

** \return    Length of message (if the message is invalid, the length will be 0).

**

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

blt_int8u CanReceivePacket(blt_int8u *data)

{

  blt_int32u rxMsgId;

  blt_bool   result = BLT_FALSE;

  blt_int8u  length = 0;

  static blt_int8u readData[BOOT_COM_RX_MAX_DATA];

  static blt_int8u receivedLen = 0;

  static blt_int8u lastLen = 0;

  static blt_int8u toReceive = 0;

  blt_int8u canData[8];

  blt_int8u restLen;

  blt_int8u canLength;

  blt_int8u idx;

  blt_int32u compID;

#if (BOOT_GATE_CAN_ENABLE > 0)

  if (commandSend == BLT_TRUE) {

    compID = (blt_int32u)BOOT_COM_CAN_TX_MSG_ID;

  } else {

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

    compID = (blt_int32u)BOOT_COM_CAN_RX_MSG_ID;

#if (BOOT_GATE_CAN_ENABLE > 0)

  }

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

  /* check if a new message was received  or is more to come */

  while ((CANx->RF0R&(blt_int32u)0x00000003) > 0 || receivedLen < toReceive)

  {

    /* wait for a transmission if required */

    while (receivedLen < toReceive && (CANx->RF0R&(blt_int32u)0x00000003) == 0) {

      /* keep the watchdog happy */

      CopService();

    }

    /* read out the message identifier */

    rxMsgId = (blt_int32u)0x000007FF & (CANx->sFIFOMailBox[0].RIR >> 21);

    /* is this the packet identifier */

    if (rxMsgId == compID)

    {

      result = BLT_TRUE;

      /* save length */

      canLength = (blt_int8u)0x0F & CANx->sFIFOMailBox[0].RDTR;

      /* store the received packet data */

      canData[0] = (blt_int8u)0xFF & CANx->sFIFOMailBox[0].RDLR;

      canData[1] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 8);

      canData[2] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 16);

      canData[3] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDLR >> 24);

      canData[4] = (blt_int8u)0xFF & CANx->sFIFOMailBox[0].RDHR;

      canData[5] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 8);

      canData[6] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 16);

      canData[7] = (blt_int8u)0xFF & (CANx->sFIFOMailBox[0].RDHR >> 24);

#if (CAN_DEBUG > 0)

      if ((receivedLen == 0 && (rxMsgId & (blt_int32u)BOOT_COM_CAN_MSG_SUBSEQUENT) != 0) ||

          (receivedLen > 0 && (rxMsgId & (blt_int32u)BOOT_COM_CAN_MSG_SUBSEQUENT) == 0)) {

        blinkSOS(4);

        msleep(500);

        visualizeByte(toReceive, 1);

        msleep(500);

        visualizeByte(receivedLen, 1);

        msleep(500);

        visualizeData((blt_int8u*)&rxMsgId, 2, 1);

        msleep(500);

        blinkSOSinf();

      }

#endif /* CAN_DEBUG > 0 */

      /* if this is the first transmission of this packet */

      if (receivedLen == 0) {

        /* abort if the message was meant for someone else */

        blt_int32u deviceID = (((blt_int32u)canData[3]) << 24) | \

                              (((blt_int32u)canData[2]) << 16) | \

                              (((blt_int32u)canData[1]) <<  8) | \

                              (((blt_int32u)canData[0]));

#if (BOOT_GATE_ENABLE > 0)

#if defined(BOOT_COM_DEVICE_LEGACY_ID)

        if ((commandSend == BLT_TRUE && deviceID == 0) ||

            (commandSend != BLT_TRUE && (deviceID == (blt_int32u)BOOT_COM_DEVICE_ID || deviceID == (blt_int32u)BOOT_COM_DEVICE_LEGACY_ID))) {

#else

        if ((commandSend == BLT_TRUE && deviceID == 0) ||

            (commandSend != BLT_TRUE && (deviceID == (blt_int32u)BOOT_COM_DEVICE_ID))) {

#endif

#else

        if (deviceID == (blt_int32u)BOOT_COM_DEVICE_ID) {

#endif

          /* store length of the packet */

          toReceive = canData[4];

          lastLen = canData[4];

          idx = 5;

          /* modify the listening address for filtering of subsequent transmissions */

          compID |= (blt_int32u)BOOT_COM_CAN_MSG_SUBSEQUENT;

        } else {

          /* release FIFO0 */

          CANx->RF0R |= CAN_BIT_RFOM0;

          break;

        }

      }

      /* if this is a subsequent transmission of a packet */

      else {

        /* store rest length and check if possible */

        restLen = canData[0];

#if (CAN_DEBUG > 0)

        if (restLen != toReceive-receivedLen ||

            canLength > restLen+1 ||

            lastLen-restLen != ((lastLen==toReceive) ? 3 : 7)) {

          /* transmission has been lost */

          blinkSOS(2);

          msleep(500);

          visualizeData((blt_int8u*)&rxMsgId, 4, 1);

          msleep(500);

          visualizeByte(toReceive, 1);

          msleep(500);

          visualizeByte(receivedLen, 1);

          msleep(500);

          visualizeByte(lastLen, 1);

          msleep(500);

          visualizeByte(restLen, 1);

          msleep(500);

          visualizeByte(canLength, 1);

          msleep(500);

          visualizeData(readData, receivedLen, 1);

          blinkSOSinf();

        }

#endif /* CAN_DEBUG > 0 */

        lastLen = restLen;

        idx = 1;

      }

      /* store the payload */

      for (; idx < canLength; idx++) {

        readData[receivedLen] = canData[idx];

        receivedLen++;

      }

      /* release FIFO0 */

      CANx->RF0R |= CAN_BIT_RFOM0;

      /* send acknowledgement */

      CANx->sTxMailBox[0].TIR &= CAN_BIT_TXRQ;

      CANx->sTxMailBox[0].TIR |= ((rxMsgId | (blt_int32u)BOOT_COM_CAN_MSG_ACK) << 21);

      CANx->sTxMailBox[0].TDTR = 1;

      CANx->sTxMailBox[0].TDLR = (((blt_int32u)0 << 24) | \

                                  ((blt_int32u)0 << 16) | \

                                  ((blt_int32u)0 <<  8) | \

                                  ((blt_int32u)(toReceive-receivedLen)));

      CANx->sTxMailBox[0].TDHR = (((blt_int32u)0 << 24) | \

                                  ((blt_int32u)0 << 16) | \

                                  ((blt_int32u)0 <<  8) | \

                                  ((blt_int32u)0));

      /* request the start of message transmission */

      CANx->sTxMailBox[0].TIR |= CAN_BIT_TXRQ;

      /* wait for transmit completion */

      while ((CANx->TSR&CAN_BIT_TME0) == 0)

      {

        /* keep the watchdog happy */

        CopService();

      }

      /* check if full package has been received */

      if (receivedLen == toReceive) {

#if (BOOT_GATE_CAN_ENABLE > 0)

        commandSend = BLT_FALSE;

#endif /* BOOT_GATE_CAN_ENABLE > 0 */

        for (idx = 0; idx < toReceive; idx++) {

          data[idx] = readData[idx];

        }

        length = toReceive;

        /* reset static variables */

        receivedLen = 0;

        toReceive = 0;

        break;

      } else {

#if (CAN_DEBUG > 0)

        if (receivedLen > toReceive) {

          /* something strange happened */

          blinkSOS(3);

          msleep(500);

          visualizeByte(toReceive, 1);

          msleep(500);

          visualizeByte(receivedLen, 1);

          blinkSOSinf();

        }

#endif /* CAN_DEBUG > 0 */

        length = 0;

      }

    } else {

      /* release FIFO0 */

      CANx->RF0R |= CAN_BIT_RFOM0;

    }

  }

  return length;

} /*** end of CanReceiveSinglePacket ***/

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

** \brief     Receives some communication interface packets if they are present.

** \param     data Pointer to byte array where the data is to be stored.

** \return    Length of message (if the message is invalid, the length will be 0).

**

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

#if (0)

blt_int8u CanReceivePacket(blt_int8u *data)

{

  static blt_int8u canPacketData[8];

  static blt_int8u canData[BOOT_COM_RX_MAX_DATA];

  static blt_int8u receivedLength = 0;

  static blt_int8u toReceive = 0;

  // get CAN packet

  blt_int8u len = CanReceiveSinglePacket(canPacketData);

  // check, if packet has been received

  if (len == 0) {

    return 0;

  }

  // if it's the first packet of a flow, save data length

  blt_int8u startRead = 0;

  if (receivedLength == 0) {

    toReceive = canPacketData[0];

    startRead = 1;

  }

  // copy CAN packet data into complete data packet

  blt_int8u canIdx = 0;

  while (receivedLength < toReceive && canIdx < 8) {

    canData[receivedLength] = canPacketData[canIdx];

    receivedLength++;

    canIdx++;

  }

  // check, if data packet is finished

  if (receivedLength == toReceive) {

    receivedLength = 0;

    CpuMemCopy((blt_int32u)data, (blt_int32u)&canData[0], toReceive);

    return toReceive;

  } else {

    return 0;

  }

} /*** end of CanReceivePacket ***/

#endif

#endif /* BOOT_COM_CAN_ENABLE > 0 || BOOT_GATE_CAN_ENABLE > 0 */

/*********************************** end of can.c **************************************/