root / toolbox / freemodbus / port / porttimer.c @ 036b4f9a
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/*
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* FreeModbus Libary: ATMega168 Port
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* Copyright (C) 2006 Christian Walter <wolti@sil.at>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* File: $Id: porttimer.c,v 1.4 2006/09/03 11:53:10 wolti Exp $
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*/
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/* ----------------------- AVR includes -------------------------------------*/
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#include <avr/io.h> |
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#include <avr/interrupt.h> |
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/* ----------------------- Platform includes --------------------------------*/
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#include "port.h" |
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/* ----------------------- Modbus includes ----------------------------------*/
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#include "mb.h" |
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#include "mbport.h" |
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/* ----------------------- Defines ------------------------------------------*/
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#define MB_TIMER_PRESCALER ( 1024UL ) |
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#define MB_TIMER_TICKS ( F_CPU / MB_TIMER_PRESCALER )
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#define MB_50US_TICKS ( 20000UL ) |
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/* ----------------------- Static variables ---------------------------------*/
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static USHORT usTimerOCRADelta;
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//static USHORT usTimerOCRBDelta;
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/* ----------------------- Start implementation -----------------------------*/
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BOOL |
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xMBPortTimersInit( USHORT usTim1Timerout50us ) |
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{ |
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/* Calculate overflow counter an OCR values for Timer1. */
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usTimerOCRADelta = |
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( MB_TIMER_TICKS * usTim1Timerout50us ) / ( MB_50US_TICKS ); |
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TCCR1A = 0x00;
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TCCR1B = 0x00;
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TCCR1C = 0x00;
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vMBPortTimersDisable( ); |
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return TRUE;
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} |
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inline void |
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vMBPortTimersEnable( ) |
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{ |
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TCNT1 = 0x0000;
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if( usTimerOCRADelta > 0 ) |
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{ |
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TIMSK1 |= _BV( OCIE1A ); |
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OCR1A = usTimerOCRADelta; |
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} |
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TCCR1B |= _BV( CS12 ) | _BV( CS10 ); |
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} |
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inline void |
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vMBPortTimersDisable( ) |
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{ |
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/* Disable the timer. */
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TCCR1B &= ~( _BV( CS12 ) | _BV( CS10 ) ); |
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/* Disable the output compare interrupts for channel A/B. */
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TIMSK1 &= ~( _BV( OCIE1A ) ); |
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/* Clear output compare flags for channel A/B. */
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TIFR1 |= _BV( OCF1A ) ; |
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} |
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SIGNAL( SIG_OUTPUT_COMPARE1A ) |
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{ |
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( void )pxMBPortCBTimerExpired( );
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} |
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