can.c

我个人编写的车载dvd上的程序

/* Includes ------------------------------------------------------------------*/
#include "public.h"

/* Private variables ---------------------------------------------------------*/
volatile unsigned char Can_Page;

/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name : CAN_Init
* Description   : This routine configures the CAN cell and active it.
* Input         : CAN_MasterCtrlReg (options of the CAN controller)
				  - CMCR_ABOM: Automatic bus-off management -> left
				  automatically by HW once 128 x 11 recessive bits,
				  - CMCR_AWUM: Automatic Wake-up mode,
				  - CMCR_NART: No Automatic Retransmission,
				  - CMCR_RFLM: Discard last message when FIFO full,
				  - CMCR_TXFP: Transmit order by FIFO -> Priority by the
				  request order or identifier of the message.
* Output        : .
* Return        : .
*******************************************************************************/  
void CAN_Init(unsigned char CAN_MasterCtrlReg)
{ 
	/* Abort the pending transmit requests */
	CAN_FPSR = CAN_TXMB0_PG;
	CAN_MCSR |= MCSR_ABRQ;    

	CAN_FPSR = CAN_TXMB1_PG;
	CAN_MCSR |= MCSR_ABRQ;
	
	CAN_FPSR = CAN_TXMB2_PG;
	CAN_MCSR |= MCSR_ABRQ;
	
	CAN_MCR |= CMCR_INRQ;				/* Request initialisation */
	while ( !(CAN_MSR & CMSR_INAK) ); 	/* Wait until acknowledged */

	/*
		Clear Transmit mailbox empty interrupts (RQCP 0 & 1 & 2) and therefore
		clear TXOK 0 & 1 & 2 bits
	*/
	CAN_TSR |= CTSR_RQCP0 | CTSR_RQCP1 | CTSR_RQCP2;
	
	/* Release the Receive FIFO -> clear FMP bits and FULL bit */
	while(CAN_RFR & CRFR_FMP01)
	{
		CAN_RFR = CRFR_RFOM;
	}
	
	/* Clear the FIFO Overrun (FOVR) bit */
	CAN_RFR |= CRFR_FOVR;
	
	/* Clear Wake-up pending interrupt */
	CAN_MSR = CMSR_WKUI;

	/* ABOM - /NART - TXFP */
	CAN_MCR |= CAN_MasterCtrlReg;

	/* Filter initialization */
	/* Deactivate all filters */
	CAN_FPSR = CAN_CTRL_PG ; 
	CAN_FCR1 = 0x00;
	CAN_FCR2 = 0x00;
	CAN_FCR3 = 0x00;
	/* Filter 0, 1, 2, 3 in Identifier/Mask mode */
	CAN_FMR1 = 0x00;
	/* Filter 4, 5 in Identifier/Mask mode */
	CAN_FMR2 = 0x00;

	/* Select filter 0:1 Page */
	CAN_FPSR = CAN_FILTER01_PG;
	
	/* All ID values are accepted */
	CAN_FxR0 = 0x00;
	CAN_FxR1 = 0x00;
	CAN_FxR2 = 0x00;
	CAN_FxR3 = 0x00;
	CAN_FxR4 = 0x00;
	CAN_FxR5 = 0x00;
	CAN_FxR6 = 0x00;
	CAN_FxR7 = 0x00;
	
	CAN_FPSR = CAN_CTRL_PG ;
	/* Filter 0 active in 1 x 32-bit registers */
	CAN_FCR1 = 0x07;

	/* Configure bit timing */
	CAN_FPSR = CAN_CTRL_PG;
	CAN_BTR1 = CAN_CBTR0_REGISTER;		// see can.h for modification of
	CAN_BTR2 = CAN_CBTR1_REGISTER;  	// bit timing parameters.

	CAN_DGR |= CDGR_3TX;	/* 3 Tx mailboxes */ 
  
	CAN_MCR &= ~CMCR_INRQ;				/* Leave the Init mode */
	while ( (CAN_MSR & CMSR_INAK) );	/* Wait until acknowledged */ 
}


/*******************************************************************************
* Function Name : CAN_Sleep
* Description   : This routine puts the CAN to bed.
* Input         : .
* Output        : .
* Return        : .
*******************************************************************************/
void CAN_Sleep(void)
{
	CAN_MCR |= CMCR_SLEEP;		/* Set Sleep mode */
	while( !(CAN_MSR & CMSR_SLAK) );	/* Wait for Sleep acknowledge */
}


/*******************************************************************************
* Function Name : CAN_WakeUp
* Description   : This routine wakes the CAN up.
* Input         : .
* Output        : .
* Return        : .
*******************************************************************************/
void CAN_WakeUp(void)
{
	CAN_MCR &= ~CMCR_SLEEP;		/* Leave Sleep mode */
	while(CAN_MSR & CMSR_SLAK);	/* Wait until slak bit cleared */
}


/*******************************************************************************
* Function Name : CAN_DiagMode
* Description   : This routine sets the CAN in Loop-back and/or silent modes.
* Input         : CAN_Mode (CDGR_LBKM, CDGR_SILM)
* Output        : .
* Return        : .
*******************************************************************************/
void CAN_EnableDiagMode(unsigned char CAN_Mode)
{
	CAN_MCR |= CMCR_INRQ;				/* Request initialisation */
	while ( !(CAN_MSR & CMSR_INAK) ); 	/* Wait until acknowledged */
	
	/* CAN modes */
	CAN_DGR |= CAN_Mode;
	
	CAN_MCR &= ~CMCR_INRQ;				/* Leave the Init mode */
	while ( (CAN_MSR & CMSR_INAK) );	/* Wait until acknowledged */
}


/*******************************************************************************
* Function Name : CAN_DisableDiagMode
* Description   : This routine sets the CAN in Loop-back and/or silent modes.
* Input         : CAN_Mode (CDGR_LBKM, CDGR_SILM)
* Output        : .
* Return        : .
*******************************************************************************/
void CAN_DisableDiagMode (void)
{
	CAN_MCR |= CMCR_INRQ;				/* Request initialisation */
	while ( !(CAN_MSR & CMSR_INAK) ); 	/* Wait until acknowledged */
	
	/* Disable Silent/Loop-back modes */
	CAN_DGR &= ~(CDGR_LBKM | CDGR_SILM);
	
	CAN_MCR &= ~CMCR_INRQ;				/* Leave the Init mode */
	while ( (CAN_MSR & CMSR_INAK) );	/* Wait until acknowledged */
}


/*******************************************************************************
* Function Name : CanMsgTransmit
* Description   : This service initiates the transmission for the message 
                  referenced by <txData>. 
				  This service shall not be called when the CAN driver is in
                  stop or sleep mode.
* Input         : txData - Pointer to structure which contains about CAN-Id,
                  CAN-DLC,CAN-Frame Data.
									CAN-Frame Data[0] = Mailbox number (for debug) 
* Output        : .
* Return        : KCANTXOK - Request is accepted by CAN driver.
                  KCANTXFAILED - Request is not accepted by CAN driver.
*******************************************************************************/
unsigned char CanMsgTransmit(tCanMsgOject *txData)
{
	unsigned char idx, MailboxNumber;

	if(CAN_TPR & CTPR_TME0)			/* Mailbox 1 empty ? */
	{
		CAN_FPSR = CAN_TXMB0_PG;
		MailboxNumber = 1;
	}
	else if(CAN_TPR & CTPR_TME1)	/* Mailbox 2 empty ? */
	{
		CAN_FPSR = CAN_TXMB1_PG;
		MailboxNumber = 2;		
	}
	else if(CAN_TPR & CTPR_TME2)	/* Mailbox 3 empty ? */
	{
		CAN_FPSR = CAN_TXMB2_PG;
		MailboxNumber = 3;		
	}
	else
	{
		return (KCANTXFAILED);
	}

	/* Transfert ID, DLC and Data in RAM to the right Mailbox */
	CAN_MDLC = txData->dlc;
	/* Mask used to clear IDE, RTR, ExtID [17:16] -> Only Std frames are used */
	CAN_MIDR12 = (txData->stdid << 2) & 0x1FFC;
	CAN_MIDR34 = txData->extid;
	
	CAN_MDAR[0] = MailboxNumber;
	for(idx = 1; idx < CAN_MDLC; idx++)
	{
		CAN_MDAR[idx] = txData->data[idx];
	}

	CAN_MCSR |= MCSR_TXRQ;	/* Transmit Request */
	return (KCANTXOK);
} 


/*******************************************************************************
* Function Name : CanCanInterruptDisable
* Description   : This routine disables all CAN interrupts.
* Input         : .
* Output        : .
* Return        : .
*******************************************************************************/
void CanCanInterruptDisable (void)
{
	CanSavePg();

	CAN_IER = 0x00; 
	CAN_FPSR = CAN_CTRL_PG;         
	CAN_EIER = 0x00;

	CanRestorePg();
}


/*******************************************************************************
* Function Name : CanCanInterruptRestore
* Description   : This service restores all CAN interrupts.
* Input         : .
* Output        : .
* Return        : .
*******************************************************************************/
void CanCanInterruptRestore (void)
{
	CanSavePg();

	CAN_IER = 	CIER_WKUIE |	/* Wake-up Interrupt */
				CIER_FOVIE | 	/* FIFO overrun Interrupt */
				CIER_FFIE  |	/* FIFO Full Interrupt */
				CIER_FMPIE |	/* FIFO Message Pending Interrupt */
				CIER_TMEIE;		/* Transmit Mailbox Empty Interrupt */

	CAN_FPSR = CAN_CTRL_PG;
	CAN_EIER = CEIER_ERRIE|	/* Error Interrupt */
				CEIER_LECIE|	/* Last Error Code Interrupt */
				CEIER_BOFIE|	/* Bus-Off Interrupt */
				CEIER_EPVIE|	/* Error Passive Interrupt */
				CEIER_EWGIE;	/* Error Warning Interrupt */

	CanRestorePg();
}

/******************* (C) COPYRIGHT 2007 STMicroelectronics *****END OF FILE****/