Tooltron

/*

 * FreeModbus Libary: ATMega168 Port

 * Copyright (C) 2006 Christian Walter <wolti@sil.at>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * File: $Id: porttimer.c,v 1.4 2006/09/03 11:53:10 wolti Exp $

 */

/* ----------------------- AVR includes -------------------------------------*/

#include <avr/io.h>

#include <avr/interrupt.h>

#include <avr/signal.h>

/* ----------------------- Platform includes --------------------------------*/

#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/

#include "mb.h"

#include "mbport.h"

/* ----------------------- Defines ------------------------------------------*/

#define MB_TIMER_PRESCALER      ( 1024UL )

#define MB_TIMER_TICKS          ( F_CPU / MB_TIMER_PRESCALER )

#define MB_50US_TICKS           ( 20000UL )

/* ----------------------- Static variables ---------------------------------*/

static USHORT   usTimerOCRADelta;

//static USHORT   usTimerOCRBDelta;

/* ----------------------- Start implementation -----------------------------*/

BOOL

xMBPortTimersInit( USHORT usTim1Timerout50us )

{

    /* Calculate overflow counter an OCR values for Timer1. */

    usTimerOCRADelta =

        ( MB_TIMER_TICKS * usTim1Timerout50us ) / ( MB_50US_TICKS );

    TCCR1A = 0x00;

    TCCR1B = 0x00;

    TCCR1C = 0x00;

    vMBPortTimersDisable(  );

    return TRUE;

}

inline void

vMBPortTimersEnable(  )

{

    TCNT1 = 0x0000;

    if( usTimerOCRADelta > 0 )

    {

        TIMSK1 |= _BV( OCIE1A );

        OCR1A = usTimerOCRADelta;

    }

    TCCR1B |= _BV( CS12 ) | _BV( CS10 );

}

inline void

vMBPortTimersDisable(  )

{

    /* Disable the timer. */

    TCCR1B &= ~( _BV( CS12 ) | _BV( CS10 ) );

    /* Disable the output compare interrupts for channel A/B. */

    TIMSK1 &= ~( _BV( OCIE1A ) );

    /* Clear output compare flags for channel A/B. */

    TIFR1 |= _BV( OCF1A ) ;

}

SIGNAL( SIG_OUTPUT_COMPARE1A )

{

    ( void )pxMBPortCBTimerExpired(  );

}