142 lines
5.6 KiB
C
142 lines
5.6 KiB
C
/************************************************************************************//**
|
|
* \file Demo/HCS12_DevKit_S12G128_CodeWarrior/Prog/timer.c
|
|
* \brief Timer driver source file.
|
|
* \ingroup Prog_HCS12_DevKit_S12G128_CodeWarrior
|
|
* \internal
|
|
*----------------------------------------------------------------------------------------
|
|
* C O P Y R I G H T
|
|
*----------------------------------------------------------------------------------------
|
|
* Copyright (c) 2018 by Feaser http://www.feaser.com All rights reserved
|
|
*
|
|
*----------------------------------------------------------------------------------------
|
|
* L I C E N S E
|
|
*----------------------------------------------------------------------------------------
|
|
* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation, either version 3 of the License, or (at your option) any later
|
|
* version.
|
|
*
|
|
* OpenBLT 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 General Public License for more details.
|
|
*
|
|
* You have received a copy of the GNU General Public License along with OpenBLT. It
|
|
* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
|
|
*
|
|
* \endinternal
|
|
****************************************************************************************/
|
|
|
|
/****************************************************************************************
|
|
* Include files
|
|
****************************************************************************************/
|
|
#include "header.h" /* generic header */
|
|
|
|
|
|
/****************************************************************************************
|
|
* Macro definitions
|
|
****************************************************************************************/
|
|
/** \brief Number of free running timer counts in 1 millisecond. */
|
|
#define TIMER_COUNTS_PER_MS (24000)
|
|
|
|
|
|
/****************************************************************************************
|
|
* Local data declarations
|
|
****************************************************************************************/
|
|
/** \brief Local variable for storing the number of milliseconds that have elapsed since
|
|
* startup.
|
|
*/
|
|
static unsigned long millisecond_counter;
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Initializes the timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerInit(void)
|
|
{
|
|
/* reset the timer configuration. note that this also sets the default prescaler
|
|
* to 1, so the free running counter runs at the same speed as the system clock.
|
|
*/
|
|
TimerDeinit();
|
|
|
|
/* configure timer channel 0 as a 1 millisecond software timer */
|
|
TIOS_IOS0 = 1;
|
|
/* make sure timer 0 interrupt flag is cleared */
|
|
TFLG1 = TFLG1_C0F_MASK;
|
|
/* generate output compare event in 1 milliseconds from now */
|
|
TC0 = TCNT + TIMER_COUNTS_PER_MS;
|
|
/* enable the interrupt for timer channel 0 */
|
|
TIE_C0I = 1;
|
|
/* enable the timer subsystem */
|
|
TSCR1_TEN = 1;
|
|
/* reset the millisecond counter */
|
|
TimerSet(0);
|
|
} /*** end of TimerInit ***/
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Stops and disables the timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerDeinit(void)
|
|
{
|
|
/* bring the timer subsystem back into its reset state */
|
|
TIE = 0;
|
|
TSCR1 = 0;
|
|
TSCR2 = 0;
|
|
TIOS = 0;
|
|
TTOV = 0;
|
|
TCTL1 = 0;
|
|
TCTL2 = 0;
|
|
TCTL3 = 0;
|
|
TCTL4 = 0;
|
|
} /*** end of TimerDeinit ***/
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Sets the initial counter value of the millisecond timer.
|
|
** \param timer_value initialize value of the millisecond timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerSet(unsigned long timer_value)
|
|
{
|
|
/* set the millisecond counter */
|
|
millisecond_counter = timer_value;
|
|
} /*** end of TimerSet ***/
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Obtains the counter value of the millisecond timer.
|
|
** \return Current value of the millisecond timer.
|
|
**
|
|
****************************************************************************************/
|
|
unsigned long TimerGet(void)
|
|
{
|
|
/* read and return the millisecond counter value */
|
|
return millisecond_counter;
|
|
} /*** end of TimerGet ***/
|
|
|
|
|
|
#pragma CODE_SEG __NEAR_SEG NON_BANKED
|
|
/************************************************************************************//**
|
|
** \brief Interrupt service routine of the timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
__interrupt void TimerISRHandler(void)
|
|
{
|
|
/* make sure timer 0 interrupt flag is cleared */
|
|
TFLG1 = TFLG1_C0F_MASK;
|
|
/* generate output compare event in 1 milliseconds from now */
|
|
TC0 += TIMER_COUNTS_PER_MS;
|
|
/* increment the millisecond counter */
|
|
millisecond_counter++;
|
|
} /*** end of TimerISRHandler ***/
|
|
#pragma CODE_SEG DEFAULT
|
|
|
|
|
|
/*********************************** end of timer.c ************************************/
|