113 lines
4.8 KiB
C
113 lines
4.8 KiB
C
/************************************************************************************//**
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* \file Demo\ARM7_LPC2000_Olimex_LPC_L2294_Crossworks\Prog\timer.c
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* \brief Timer driver source file.
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* \ingroup Prog_ARM7_LPC2000_Olimex_LPC_L2294_Crossworks
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* \internal
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*----------------------------------------------------------------------------------------
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* C O P Y R I G H T
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*----------------------------------------------------------------------------------------
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* Copyright (c) 2011 by Feaser http://www.feaser.com All rights reserved
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*
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*----------------------------------------------------------------------------------------
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* L I C E N S E
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*----------------------------------------------------------------------------------------
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* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as published by the Free
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* Software Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
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* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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* PURPOSE. See the GNU General Public License for more details.
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*
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* You have received a copy of the GNU General Public License along with OpenBLT. It
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* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
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*
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* \endinternal
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****************************************************************************************/
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/****************************************************************************************
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* Include files
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****************************************************************************************/
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#include "header.h" /* generic header */
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/****************************************************************************************
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* Local data declarations
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****************************************************************************************/
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/** \brief Local variable for storing the number of milliseconds that have elapsed since
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* startup.
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*/
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static unsigned long millisecond_counter;
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/****************************************************************************************
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* External functions
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****************************************************************************************/
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extern void TIMER0_ISR(void);
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/************************************************************************************//**
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** \brief Initializes the timer.
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** \return none.
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**
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****************************************************************************************/
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void TimerInit(void)
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{
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/* configure timer0 as 1 ms software output compare */
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T0MR0 = BOOT_CPU_SYSTEM_SPEED_KHZ-1;
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/* enable interrupt and automatic reset upon compare */
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T0MCR = 0x01 | 0x02;
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/* enable the output compare */
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T0TCR = 0x01;
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/* set the interrupt service routine for the output compare event */
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VICVectAddr0 = (unsigned long)TIMER0_ISR;
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/* connect vectored IRQ slot 0 to Timer0's channel 4 */
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VICVectCntl0 = 0x20 | 4;
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/* enable the timer0 interrupt */
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VICIntEnable = 0x10;
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/* reset the millisecond counter */
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TimerSet(0);
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} /*** end of TimerInit ***/
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/************************************************************************************//**
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** \brief Updates the millisecond timer. Should be called every millisecond by
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** the timer interrupt service routine.
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** \return none.
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**
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****************************************************************************************/
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void TimerUpdate(void)
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{
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/* increment the millisecond counter */
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millisecond_counter++;
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} /*** end of TimerUpdate ***/
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/************************************************************************************//**
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** \brief Sets the initial counter value of the millisecond timer.
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** \param timer_value initialize value of the millisecond timer.
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** \return none.
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**
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****************************************************************************************/
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void TimerSet(unsigned long timer_value)
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{
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/* set the millisecond counter */
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millisecond_counter = timer_value;
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} /*** end of TimerSet ***/
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/************************************************************************************//**
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** \brief Obtains the counter value of the millisecond timer.
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** \return Current value of the millisecond timer.
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**
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****************************************************************************************/
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unsigned long TimerGet(void)
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{
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/* read and return the millisecond counter value */
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return millisecond_counter;
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} /*** end of TimerGet ***/
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/*********************************** end of timer.c ************************************/
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