mirror of https://github.com/rusefi/openblt.git
143 lines
6.0 KiB
C
143 lines
6.0 KiB
C
/************************************************************************************//**
|
|
* \file Source\ARM7_LPC2000\timer.c
|
|
* \brief Bootloader timer driver source file.
|
|
* \ingroup Target_ARM7_LPC2000
|
|
* \internal
|
|
*----------------------------------------------------------------------------------------
|
|
* C O P Y R I G H T
|
|
*----------------------------------------------------------------------------------------
|
|
* Copyright (c) 2011 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 should have received a copy of the GNU General Public License along with OpenBLT.
|
|
* If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
* A special exception to the GPL is included to allow you to distribute a combined work
|
|
* that includes OpenBLT without being obliged to provide the source code for any
|
|
* proprietary components. The exception text is included at the bottom of the license
|
|
* file <license.html>.
|
|
*
|
|
* \endinternal
|
|
****************************************************************************************/
|
|
|
|
/****************************************************************************************
|
|
* Include files
|
|
****************************************************************************************/
|
|
#include "boot.h" /* bootloader generic header */
|
|
|
|
|
|
/****************************************************************************************
|
|
* Local data declarations
|
|
****************************************************************************************/
|
|
/** \brief Local variable that holds the last value of the free running counter. */
|
|
static blt_int32u free_running_counter_last;
|
|
/** \brief Local variable for storing the number of milliseconds that have elapsed since
|
|
* startup.
|
|
*/
|
|
static blt_int32u millisecond_counter;
|
|
|
|
|
|
/****************************************************************************************
|
|
* Register definitions
|
|
****************************************************************************************/
|
|
/** \brief T0MCR timer register. */
|
|
#define T0MCR (*((volatile blt_int32u *) 0xE0004014))
|
|
/** \brief T0CCR timer register. */
|
|
#define T0CCR (*((volatile blt_int32u *) 0xE0004028))
|
|
/** \brief T0PR timer register. */
|
|
#define T0PR (*((volatile blt_int32u *) 0xE000400C))
|
|
/** \brief T0PC timer register. */
|
|
#define T0PC (*((volatile blt_int32u *) 0xE0004010))
|
|
/** \brief T0TCR timer register. */
|
|
#define T0TCR (*((volatile blt_int32u *) 0xE0004004))
|
|
/** \brief T0TC timer register. */
|
|
#define T0TC (*((volatile blt_int32u *) 0xE0004008))
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Initializes the polling based millisecond timer driver.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerInit(void)
|
|
{
|
|
/* disable timer 0 interrupts */
|
|
T0MCR = 0x00;
|
|
T0CCR = 0x00;
|
|
/* set prescaler so that free running counter runs at 1 kHz */
|
|
T0PR = BOOT_CPU_SYSTEM_SPEED_KHZ - 1;
|
|
/* start free running counter for timer 0 */
|
|
T0TCR = 0x01;
|
|
/* store the start value of the free running counter */
|
|
free_running_counter_last = T0TC;
|
|
/* reset the millisecond counter value */
|
|
millisecond_counter = 0;
|
|
} /*** end of TimerInit ***/
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Reset the timer by placing the timer back into it's default reset
|
|
** configuration.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerReset(void)
|
|
{
|
|
/* reset the timer */
|
|
T0TCR = 0;
|
|
/* reset the prescaler */
|
|
T0PR = 0;
|
|
/* reset the timer counter */
|
|
T0TC = 0;
|
|
/* reset the prescaled counter */
|
|
T0PC = 0;
|
|
} /* TimerReset */
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Updates the millisecond timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerUpdate(void)
|
|
{
|
|
blt_int32u free_running_counter_now;
|
|
|
|
/* update the millisecond counter */
|
|
free_running_counter_now = T0TC;
|
|
millisecond_counter += (free_running_counter_now - free_running_counter_last);
|
|
/* store current free running counter value for next time around */
|
|
free_running_counter_last = free_running_counter_now;
|
|
} /*** end of TimerUpdate ***/
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Obtains the counter value of the millisecond timer.
|
|
** \return Current value of the millisecond timer.
|
|
**
|
|
****************************************************************************************/
|
|
blt_int32u TimerGet(void)
|
|
{
|
|
/* updating timer here allows this function to be called in a loop with timeout
|
|
* detection.
|
|
*/
|
|
TimerUpdate();
|
|
|
|
/* read and return the amount of milliseconds that passed since initialization */
|
|
return millisecond_counter;
|
|
} /*** end of TimerGet ***/
|
|
|
|
|
|
/*********************************** end of timer.c ************************************/
|