LPC1768 CAN1 receive

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

 *  can.c:  CAN module API file for NXP LPC17xx Family Microprocessors

 *

 *   Copyright(C) 2009, NXP Semiconductor

 *   All rights reserved.

 *

 *   History

 *   2009.05.27  ver 1.00    Prelimnary version, first Release

 *   13.10.2010  ver 1.1     Änderung bezüglich CAN2

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

#include "lpc17xx.h"

#include "type.h"

#include "can.h"

/* Receive Queue: one queue for each CAN port */

extern CAN_MSG MsgBuf_RX1;

extern volatile uint32_t CAN1RxDone;

volatile uint32_t CANStatus;

uint32_t CAN1RxCount = 0;

uint32_t CAN1ErrCount = 0;

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

** Function name:    CAN_ISR_Rx1

**

** Descriptions:    CAN Rx1 interrupt handler

**

** parameters:      None

** Returned value:    None

** 

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

void CAN_ISR_Rx1( void )

{

  uint32_t * pDest;

  /* initialize destination pointer  */

  pDest = (uint32_t *)&MsgBuf_RX1;

  *pDest = LPC_CAN1->RFS;  /* Frame  */

  pDest++;

  *pDest = LPC_CAN1->RID; /* ID  */

  pDest++;

  *pDest = LPC_CAN1->RDA; /* Data A */

  pDest++;

  *pDest = LPC_CAN1->RDB; /* Data B  */

  CAN1RxDone = TRUE;

  LPC_CAN1->CMR = 0x04; /* release receive buffer */

  return;

}

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

** Function name:    CAN_Handler

**

** Descriptions:    CAN interrupt handler

**

** parameters:      None

** Returned value:    None

** 

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

void CAN_IRQHandler(void)  

{    

  CANStatus = LPC_CANCR->CANRxSR;

  if ( CANStatus & (1 << 8) )

  {

  CAN1RxCount++;

  CAN_ISR_Rx1();

  }

  if ( LPC_CAN1->GSR & (1 << 6 ) )

  {

  /* The error count includes both TX and RX */

  CAN1ErrCount = LPC_CAN1->GSR >> 16;

  }

  return;

}

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

** Function name:    CAN_Init

**

** Descriptions:    Initialize CAN, install CAN interrupt handler

**

** parameters:      bitrate

** Returned value:    true or false, false if initialization failed.

** 

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

uint32_t CAN_Init( uint32_t can_btr )

{

  CAN1RxDone = FALSE;

  LPC_SC->PCONP |= ((1<<13)|(1<<14));  /* Enable CAN1 and CAN2 clock */

  LPC_PINCON->PINSEL0 &= ~0x0000000F;  /* CAN1 is p0.0 and p0.1  */

  LPC_PINCON->PINSEL0 |= 0x00000005;  

  LPC_CAN1->MOD = 1;    /* Reset CAN */

  LPC_CAN1->IER = 0;    /* Disable Receive Interrupt */

  LPC_CAN1->GSR = 0;    /* Reset error counter when CANxMOD is in reset  */

  LPC_CAN1->BTR = can_btr;

  LPC_CAN1->MOD = 0x0;  /* CAN in normal operation mode */

  LPC_CAN1->IER = 0x01; /* Enable receive interrupts */

  return( TRUE );

}

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

** Function name:    CAN_SetACCF_Lookup

**

** Descriptions:    Initialize CAN, install CAN interrupt handler

**

** parameters:      bitrate

** Returned value:    true or false, false if initialization failed.

** 

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

void CAN_SetACCF_Lookup( void )

{

  uint32_t address = 0;

  uint32_t i;

  uint32_t ID_high, ID_low;

  /* Set explicit standard Frame */ 

  LPC_CANAF->SFF_sa = address;

  for ( i = 0; i < ACCF_IDEN_NUM; i += 2 )

  {

  ID_low = (i << 29) | (EXP_STD_ID << 16);

  ID_high = ((i+1) << 13) | (EXP_STD_ID << 0);

  *((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low | ID_high;

  address += 4; 

  }

  /* Set group standard Frame */

  LPC_CANAF->SFF_GRP_sa = address;

  for ( i = 0; i < ACCF_IDEN_NUM; i += 2 )

  {

  ID_low = (i << 29) | (GRP_STD_ID << 16);

  ID_high = ((i+1) << 13) | (GRP_STD_ID << 0);

  *((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low | ID_high;

  address += 4; 

  }

  /* Set explicit extended Frame */ 

  LPC_CANAF->EFF_sa = address;

  for ( i = 0; i < ACCF_IDEN_NUM; i++  )

  {

  ID_low = (i << 29) | (EXP_EXT_ID << 0);

  *((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low;

  address += 4; 

  }

  /* Set group extended Frame */

  LPC_CANAF->EFF_GRP_sa = address;

  for ( i = 0; i < ACCF_IDEN_NUM; i++  )

  {

  ID_low = (i << 29) | (GRP_EXT_ID << 0);

  *((volatile uint32_t *)(LPC_CANAF_RAM_BASE + address)) = ID_low;

  address += 4; 

  }

  /* Set End of Table */

  LPC_CANAF->ENDofTable = address;

  return;

}

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

** Function name:    CAN_SetACCF

**

** Descriptions:    Set acceptance filter and SRAM associated with  

**

** parameters:      ACMF mode

** Returned value:    None

**

** 

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

void CAN_SetACCF( uint32_t ACCFMode )

{

  switch ( ACCFMode )

  {

  case ACCF_OFF:

    LPC_CANAF->AFMR = ACCFMode;

    LPC_CAN1->MOD = LPC_CAN2->MOD = 1;  // Reset CAN

    LPC_CAN1->IER = LPC_CAN2->IER = 0;  // Disable Receive Interrupt

    LPC_CAN1->GSR = LPC_CAN2->GSR = 0;  // Reset error counter when CANxMOD is in reset

  break;

  case ACCF_BYPASS:

    LPC_CANAF->AFMR = ACCFMode;

  break;

  case ACCF_ON:

  case ACCF_FULLCAN:

    LPC_CANAF->AFMR = ACCF_OFF;

    CAN_SetACCF_Lookup();

    LPC_CANAF->AFMR = ACCFMode;

  break;

  default:

  break;

  }

  return;

}

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

** Function name:    CAN1_SendMessage

**

** Descriptions:    Send message block to CAN1  

**

** parameters:      pointer to the CAN message

** Returned value:    true or false, if message buffer is available,

**            message can be sent successfully, return TRUE,

**            otherwise, return FALSE.

** 

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

uint32_t CAN1_SendMessage( CAN_MSG *pTxBuf )

{

  uint32_t CANStatus;

  CANStatus = LPC_CAN1->SR;

  if ( CANStatus & 0x00000004 )

  {

  LPC_CAN1->TFI1 = pTxBuf->Frame & 0xC00F0000;

  LPC_CAN1->TID1 = pTxBuf->MsgID;

  LPC_CAN1->TDA1 = pTxBuf->DataA;

  LPC_CAN1->TDB1 = pTxBuf->DataB;

  LPC_CAN1->CMR = 0x21;

  return ( TRUE );

  }

  else if ( CANStatus & 0x00000400 )

  {

  LPC_CAN1->TFI2 = pTxBuf->Frame & 0xC00F0000;

  LPC_CAN1->TID2 = pTxBuf->MsgID;

  LPC_CAN1->TDA2 = pTxBuf->DataA;

  LPC_CAN1->TDB2 = pTxBuf->DataB;

  LPC_CAN1->CMR = 0x41;

  return ( TRUE );

  }

  else if ( CANStatus & 0x00040000 )

  {  

  LPC_CAN1->TFI3 = pTxBuf->Frame & 0xC00F0000;

  LPC_CAN1->TID3 = pTxBuf->MsgID;

  LPC_CAN1->TDA3 = pTxBuf->DataA;

  LPC_CAN1->TDB3 = pTxBuf->DataB;

  LPC_CAN1->CMR = 0x81;

  return ( TRUE );

  }

  return ( FALSE );

}

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

**                            End Of File

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