slic_lindriver.c

摩托罗拉公司发布的QL4的Lin总线kit,freescale网站上花钱买的

//_______________________________________________________________________________
// Title: SLIC_LINdriver.c                    Copyright (c) Motorola 2003
//
// Assembler:  P&E Microcomputer Systems - CASM08Z  (v3.16)
// Compiler:   Codewarrior....
//
// Revision History:
// Rev #      Date       Who     Comments
// ------  -----------   ------  ------------------------------------------------
//  0.1     11-Aug-03    MR      Initial release - 
//
// Filename:     LINQL4-C/src/SLIC_LINdriver.c
// Author:       Matt Ruff
// Revision:     0.1
//
// Functions:    SLIC module routines
//
// History:      
//
// Description:  
//
// Notes:        
//
//_______________________________________________________________________________

#include "global.h"
#include "MC68HC908QL4.h"
#include "SLIC_LINdriver.h"

extern unsigned char temp_msg_buffer[8];	// Temporary storage of SLIC buffer contents
extern unsigned char LINdata;
extern unsigned char LINID;
extern unsigned char BusOff;
extern unsigned char LINSleep;

//+-----------------------------------------------------------------------------+
//|  SLIC_Init - Initializes SLIC module                                        |
//|                                                                             |
//|  Configures SLIC for:                                                       |
//|        1. LIN or BTM mode operation                                         |
//|        2. Clock Operation in MCU Wait Mode                                  |
//|        3. Receive filter prescaler adjustment for data rate                 |
//|        4. Bit timing setting (BTM mode)                                     |
//+-----------------------------------------------------------------------------+
void SLIC_Init(void)
	{
	SLCC1_INITREQ = 0;					// Clear INITREQ bit in SLIC
	while(SLCS_INITACK==1){;;}    		// Wait for INITACK to clear
	SLCC2_SLCWCM = 0;             		// Wait Clock Mode
										//  0 - SLIC clocks continue in CPU WAIT
										//  1 - SLIC clocks stop in CPU WAIT
//	SLCP = 0x80;                  		// RX Filter Prescaler
										//   This is only used if a value other 
										//   than the default is desired.
								     	//   00 - div 1
								     	//   01 - div 2
								     	//   10 - div 3  (default setting)
								     	//   11 - div 4
	SLCC2_SLCE = 1;						// Enable SLIC module								     	
	}

//+-----------------------------------------------------------------------------+
//|                                                                             |
//|  SLIC_ISR - Interrupt Service Routine                                       |
//|                                                                             |
//|  Main handler for SLIC interrupts                                           |
//|                                                                             |
//+-----------------------------------------------------------------------------+
//____________________________SLIC_ISR_____________
#pragma TRAP_PROC
void SLIC_ISR(void)
	{
	unsigned char temp_SLCSV = 0;
			 char ID_found = 0;			// If ID not found, set IMSG
			 char temp = PTB_PTB0;
	
	temp_SLCSV = SLCSV;					// Read SLCSV value 
	
	switch(temp_SLCSV)					// switch is temporary measure
		{
		case 0x00:    //___________No Interrupts Pending__________________
		break;

		case 0x04:    //___________No Bus Activity________________________
		    BusOff++;
		    if (BusOff == 2)
			    {	
		    	LINSleep = 1;		// Set LINSleep flag
				BusOff = 0;			// Reset BusOff counter
			    }
		break;

		case 0x08:    //___________TX Buffer Empty - Checksum Sent_______
		break;

		case 0x0C:    //___________TX Buffer Empty_______________________
		break;

		case 0x10:    //___________RX Buffer Full - Checksum OK__________

		//_________________________________________________________________________TEST____________
		if(SLCID==0x97)		// Test message from master
			{								// --------- test code....
			temp_msg_buffer[0] = SLCD0;		// Load RAM from RX buffers
			temp_msg_buffer[1] = SLCD1;		// Load RAM from RX buffers
			}					  
		//_________________________________________________________________________TEST________
		break;

		case 0x14:    //___________RX Buffer Full - No errors____________
		break;

		case 0x18:    //___________Bit-Error_____________________________
		break;

		case 0x1C:    //___________RX Buffer Overrun_____________________
		break;

		case 0x20:    //___________<reserved>____________________________
		break;

		case 0x24:    //___________Checksum Error________________________
		break;

		case 0x28:    //___________Byte Framing Error____________________
		break;

		case 0x2C:    //___________ID received correctly - parity OK_____
			          //           Perform ID lookup
		//_________________________________________________________________________
		if(SLCID==LINID)			// Check ID
			{						
			ID_found = 1;			// Set ID found flag
			SLCD0 	 = LINdata;		// Load TX buffers
			SLCD1    = 0;
			SLCDLC   = 0xC1;		// Write DLC code to start TX - STD CHECKSUM
			}					  
		//_________________________________________________________________________
		if(SLCID==0x97)		// Test message from master
			{								// --------- test code....
    			ID_found = 1;				// Set ID found flag			
    			SLCDLC = 0x41;				// Write DLC code = RX, STANDARD CHECKSUM, 2 bytes
			}					  
		//_________________________________________________________________________

		if (ID_found == 0)
		    {
                                #warning "ALPHA SAMPLE WORKAROUND"
            SLCDLC = 0x00;      // Alpha sample workaround - write DLC = 0 before IMSG=1;
		    SLCC1_IMSG = 1;	    // Set IMSG bit to ignore ID if not found!
		    }
		ID_found = 0;		    // reset ID_found (should do anyway on re-entry into ISR)
		
		LINSleep = 0;		    // Clear LINSleep flag - there is bus activity
		
		break;
		case 0x30:    //___________ID Parity Error______________________
		break;

		case 0x34:    //___________Inconsistent-Synch-Field Error_______
		break;

		case 0x38:    //___________<reserved>___________________________
		break;

		case 0x3C:    //___________Wakeup_______________________________
		break;
		}			//___ end switch temp_SLCSV

	SLCS_SLCF = 1;				// Clear SLIC interrupt flag
	} //_______________________________________________end_SLIC_ISR_______