can.c

sample Of CAN with LPC23XX processor

/*****************************************************************************
 *  can.c:  CAN module API file for NXP LPC23xx/24xx Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.09.13  ver 1.00    Prelimnary version, first Release
 *
*****************************************************************************/
#include "LPC23xx.h"					/* LPC23xx definitions */
#include "type.h"
#include "irq.h"
#include "can.h"

// Receive Queue: one queue for each CAN port
extern CAN_MSG MsgBuf_RX1, MsgBuf_RX2;
extern volatile DWORD CAN1RxDone, CAN2RxDone;

DWORD CANStatus;
DWORD CAN1RxCount = 0, CAN2RxCount = 0;
DWORD CAN1ErrCount = 0, CAN2ErrCount = 0;

/******************************************************************************
** Function name:		CAN_ISR_Rx1
**
** Descriptions:		CAN Rx1 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void CAN_ISR_Rx1( void )
{
	DWORD * pDest;

	// initialize destination pointer
	pDest = (DWORD *)&MsgBuf_RX1;
	*pDest = CAN1RFS;  // Frame

	pDest++;
	*pDest = CAN1RID; // ID		//change by gongjun

	pDest++;
	*pDest = CAN1RDA; // Data A

	pDest++;
	*pDest = CAN1RDB; // Data B
	
	CAN1RxDone = TRUE;
	CAN1CMR = 0x04; // release receive buffer
	return;
}

/******************************************************************************
** Function name:		CAN_ISR_Rx2
**
** Descriptions:		CAN Rx2 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void CAN_ISR_Rx2( void )
{
	DWORD *pDest;

	// initialize destination pointer
	pDest = (DWORD *)&MsgBuf_RX2;
	*pDest = CAN2RFS;  // Frame

	pDest++;
	*pDest = CAN2RID; // ID

	pDest++;
	*pDest = CAN2RDA; // Data A

	pDest++;
	*pDest = CAN2RDB; // Data B

	CAN2RxDone = TRUE;
	CAN2CMR = 0x04; // release receive buffer
	return;
}

/*****************************************************************************
** Function name:		CAN_Handler
**
** Descriptions:		CAN interrupt handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void CAN_Handler(void) __irq 
{		
    IENABLE;			/* handles nested interrupt */

	CANStatus = CAN_RX_SR;
	if ( CANStatus & (1 << 8) )
	{
		CAN1RxCount++;
		CAN_ISR_Rx1();
	}
	if ( CANStatus & (1 << 9) )
	{
		CAN2RxCount++;
		CAN_ISR_Rx2();
	}
	if ( CAN1GSR & (1 << 6 ) )
	{
		/* The error count includes both TX and RX */
		CAN1ErrCount = (CAN1GSR >> 16 );
	}
	if ( CAN2GSR & (1 << 6 ) )
	{
		/* The error count includes both TX and RX */
		CAN2ErrCount = (CAN2GSR >> 16 );
	}
    IDISABLE;
    VICVectAddr = 0;		/* Acknowledge Interrupt */
	return;
}

/******************************************************************************
** Function name:		CAN_Init
**
** Descriptions:		Initialize CAN, install CAN interrupt handler
**
** parameters:			bitrate
** Returned value:		true or false, false if initialization failed.
** 
******************************************************************************/
DWORD CAN_Init( DWORD can_btr )
{
	CAN1RxDone = CAN2RxDone = FALSE;

	PCONP |= (1 << 13) | (1 << 14);	// Enable clock to the peripheral

    PINSEL0	&= ~0x00000F0F;
	PINSEL0 |= 0x0000A05;	// port0.0~1, function 0x01, port0.4~5, function 0x10

	CAN1MOD = CAN2MOD = 1;	// Reset CAN
	CAN1IER = CAN2IER = 0;	// Disable Receive Interrupt
	CAN1GSR = CAN2GSR = 0;	// Reset error counter when CANxMOD is in reset

	CAN1BTR = CAN2BTR = can_btr;
	CAN1MOD = CAN2MOD = 0x0;	// CAN in normal operation mode

	// Install CAN interrupt handler
	install_irq( 23, (void *)CAN_Handler, HIGHEST_PRIORITY );
	CAN1IER = CAN2IER = 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 )
{
	DWORD address = 0;
	DWORD i;
	DWORD ID_high, ID_low;

	// Set explicit standard Frame  
	CAN_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 DWORD *)(CAN_MEM_BASE + address)) = ID_low | ID_high;
		address += 4; 
	}
		
	// Set group standard Frame 
	CAN_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 DWORD *)(CAN_MEM_BASE + address)) = ID_low | ID_high;
		address += 4; 
	}
 
	// Set explicit extended Frame 
	CAN_EFF_SA = address;
	for ( i = 0; i < ACCF_IDEN_NUM; i++  )
	{
		ID_low = (i << 29) | (EXP_EXT_ID << 0);
		*((volatile DWORD *)(CAN_MEM_BASE + address)) = ID_low;
		address += 4; 
	}

	// Set group extended Frame 
	CAN_EFF_GRP_SA = address;
   	for ( i = 0; i < ACCF_IDEN_NUM; i++  )
	{
		ID_low = (i << 29) | (GRP_EXT_ID << 0);
		*((volatile DWORD *)(CAN_MEM_BASE + address)) = ID_low;
		address += 4; 
	}
   
	// Set End of Table 
 	CAN_EOT = address;
	return;
}

/******************************************************************************
** Function name:		CAN_SetACCF
**
** Descriptions:		Set acceptance filter and SRAM associated with	
**
** parameters:			ACMF mode
** Returned value:		None
**
** 
******************************************************************************/
void CAN_SetACCF( DWORD ACCFMode )
{
	switch ( ACCFMode )
	{
		case ACCF_OFF:
		CAN_AFMR = ACCFMode;
		CAN1MOD = CAN2MOD = 1;	// Reset CAN
		CAN1IER = CAN2IER = 0;	// Disable Receive Interrupt
		CAN1GSR = CAN2GSR = 0;	// Reset error counter when CANxMOD is in reset
		break;

		case ACCF_BYPASS:
		CAN_AFMR = ACCFMode;
		break;

		case ACCF_ON:
		case ACCF_FULLCAN:
		CAN_AFMR = ACCF_OFF;
		CAN_SetACCF_Lookup();
		CAN_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.
** 
******************************************************************************/
DWORD CAN1_SendMessage( CAN_MSG *pTxBuf )
{
    DWORD CANStatus;

	CANStatus = CAN1SR;
	if ( CANStatus & 0x00000004 )
	{
		CAN1TFI1 = pTxBuf->Frame & 0xC00F0000;
		CAN1TID1 = pTxBuf->MsgID;
		CAN1TDA1 = pTxBuf->DataA;
		CAN1TDB1 = pTxBuf->DataB;
		CAN1CMR = 0x21;
		return ( TRUE );
	}
	else if ( CANStatus & 0x00000400 )
	{
		CAN1TFI2 = pTxBuf->Frame & 0xC00F0000;
		CAN1TID2 = pTxBuf->MsgID;
		CAN1TDA2 = pTxBuf->DataA;
		CAN1TDB2 = pTxBuf->DataB;
		CAN1CMR = 0x41;
		return ( TRUE );
	}
	else if ( CANStatus & 0x00040000 )
	{	
		CAN1TFI3 = pTxBuf->Frame & 0xC00F0000;
		CAN1TID3 = pTxBuf->MsgID;
		CAN1TDA3 = pTxBuf->DataA;
		CAN1TDB3 = pTxBuf->DataB;
		CAN1CMR = 0x81;
		return ( TRUE );
	}
	else
	{
		return ( FALSE );
	}
}

/******************************************************************************
**                            End Of File
******************************************************************************/