lin_hdw.c

针对日本瑞莎单片机r8c/23 开发的LIN网络通讯程序包括主节点和从节点

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/**********************************************************************
   Title                      : lin_hdw.c

   Module Description         : This file contains the MCU specific and hardware
                                specific variable declarations and initializations
                                for the LIN device.

   MCU Family                 : R8C

   Author                     : Bob Chamberlain

   Version                    : LIN API 2.0 Version 1.1

 *********************************************************************/
/**********************************************************************
 * Include files
 *********************************************************************/
#include "lin_api.h"
#include "rskR8C23def.h"

/**********************************************************************
 * Include User Header file
 *********************************************************************/

/**********************************************************************
 * Constant and Macro Definitions using #define
 *********************************************************************/

/**********************************************************************
 * Enumerations, Structures and Typedefs
 *********************************************************************/

/**********************************************************************
 * Global Variable extern Declarations
 *********************************************************************/
/* Set a default value for the count used to detect a valid wake-up period.
 * This threshold value of 150us detects a wakeup pulse of 250us minimum
 * even for an uncalibrated Baudrate, given the values defined in the file
 * "lin_hdw.h" for LIN_TIMER_RATE and LIN_MY_FREQUENCY.  The break timer
 * is used to detect the wake-up period.  The value 14 is loaded into the
 * timer register to count 15 periods of the prescaler.  The count calculated
 * below generates a 10us period for the prescaler.  This count is
 * calculated as follows:
 *
 *    count = ((10 * LIN_MY_FREQUENCY) / LIN_TIMER_RATE) - 1)
 *
 *    */
unsigned char LIN_wake_up_period = 99;

/* Set a default value for the count to be loaded into the break timer
 * to generate a break pulse (Master) or to detect a break pulse (Slave).
 * For a Master node, this count must equal 13 bit periods of the LIN
 * serial port.  For a Slave node, this count must equal 11 bit periods
 * of the LIN serial port.  The total count is broken up into two values:
 * one that is loaded into the timer register and one that is loaded into
 * the prescaler.  In order to achieve the maximum possible accuracy, each
 * LIN bit period is broken up into some integer number of "slices",
 * (usually 4 for a 19200Baud bit rate).  The break timer register is
 * loaded with the number of bits (13 or 11) times the number of "slices",
 * all minus 1.  The prescaler is loaded with a value to produce a period
 * equal to the LIN bit period divided by the number of slices.  The code
 * for AUTO_CALCULATION will calculate the proper values if enabled by
 * uncommenting this option in "lin_dev.h" - at least for Baud rates of
 * 19200, 9600 and 4800 with system clock frequencies of 20MHz through
 * 4MHz (in even 2MHz steps).  If AUTO_CALCULATION is enabled, any reasonable
 * values may be entered below, since they will never be used anyway.  If
 * AUTO_CALCULATION is not enabled or if your system is using some odd Baud
 * rate or system clock frequency, the correct values must be calculated as
 * outlined below.  The first step is to calculate the BIT_FACTOR, the number
 * of slices in a bit period.  This is an integer value calculated as follows:
 *
 *    BIT_FACTOR = (76800 / LIN_MY_SPEED) 
 *
 * Round BIT_FACTOR to the nearest integer.  
 *
 * The count to be loaded into the break timer prescaler register is nr of clock pulses
 * per slice (BIT_FACTOR), "LIN_break_prescale" is calculated as follows:
 *
 *  prescale = (((LIN_MY_FREQUENCY*10**6)/(LIN_SPEED*LIN_TIMER_RATE*BIT_FACTOR)) - 1)
 *
 * The count to be loaded into the * break timer register, "LIN_break_count", 
 * is then calculated as:
 *
 *    LIN_break_count = ("break period in bits"*BIT_FACTOR - 1)
 *
 * where the "break period in bits" is 13 for a Master node and 11 for a Slave
 * node.  
 *
 * The calculated value should be rounded to the nearest integer before subtracting
 * the final 1.
 *
 *    */
#if (LIN_MASTER_NODE == LIN_MY_NODE_NAME)
unsigned char LIN_break_count = 51;	/* Count for the Master break period. */
unsigned char LIN_break_prescale = 129; /* Prescale value for Master */
#else					/* 129 for 20 MHz Xtal and div by 1 */
unsigned char LIN_break_count = 43;	/* Count for the Slave break detect period. */
unsigned char LIN_break_prescale = 64;	/* Prescale value for Slave. */
#endif					/* 64  for 40 MHz int osc. div by 4 */

										
/* Set a default value for the register bits in the control register for the Baud
 * rate generator that determine the value of the prescaler.  In most cases, no
 * prescaler will be required, but this must be checked for each MCU, Baud rate
 * and MCU clock frequency selected.  The value of 0 is valid for all R8C/Tiny MCU's
 * operating at 20MHz or less with a 19200 LIN Baud rate.  */
unsigned char LIN_smr_value = 0; /* Load value for the prescale select bits.  */

/* Set a default value for the Baud rate generator divide value.  This system
 * clock is divided by 16, divided by the prescale value selected "LIN_smr_value"
 * and divided by this BRG value to produce the desired Baud rate.  It can be
 * calculated as follows:
 *
 *    BRG value = ((LIN_MY_FREQUENCY * 10**6) / (16 * total-uart-clock-prescale * LIN_SPEED)) - 1
 *
 * The calculated value should be rounded to the nearest integer value before
 * subtracting 1.  */
#if (LIN_MASTER_NODE == LIN_MY_NODE_NAME)
unsigned char LIN_brr_value = 64; /* 64 for 20 MHz Xtal and div by 1 */
#else
unsigned char LIN_brr_value = 32; /* 32 for 40 MHz int osc. div by 4 */
#endif

/**********************************************************************
 * Function Definitions
 *********************************************************************/
#if (LIN_MASTER_NODE == LIN_MY_NODE_NAME)
   #ifdef DEDICATED_SCHEDULE_TIMER
      #pragma INTERRUPT LIN_Schedule_ISR
   #endif
#endif
#pragma INTERRUPT LIN_Break_ISR
#pragma INTERRUPT LIN_Xmt_ISR
#pragma INTERRUPT LIN_Rcv_ISR

#if (LIN_MASTER_NODE == LIN_MY_NODE_NAME)
   #ifdef DEDICATED_SCHEDULE_TIMER
      void LIN_Schedule_ISR(void)
      {
         l_sch_tick(LIN);
         return;
      }
   #endif
#endif

void LIN_Break_ISR(void)
{
   l_ifc_aux(LIN);
	/* Turn off all LEDs for demo. Signals turn them on */
	RED_LED2 = RED_LED = YLW_LED = GRN_LED = LED_OFF;
   return;
}

void LIN_Xmt_ISR(void)
{
   l_ifc_tx(LIN);
   return;
}

void LIN_Rcv_ISR(void)
{
   l_ifc_rx(LIN);
   return;
}

/**********************************************************************
 *
 * Modification Record
 *
 **********************************************************************
 *
 *    Version 1.1 for R8C 16 Mar 2006   Bob Chamberlain
 *
 *********************************************************************/