145 lines
5.9 KiB
C
145 lines
5.9 KiB
C
/************************************************************************************//**
|
|
* \file Source/TRICORE_TC1798/timer.c
|
|
* \brief Bootloader timer driver source file.
|
|
* \ingroup Target_TRICORE_TC1798
|
|
* \internal
|
|
*----------------------------------------------------------------------------------------
|
|
* C O P Y R I G H T
|
|
*----------------------------------------------------------------------------------------
|
|
* Copyright (c) 2015 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 "boot.h" /* bootloader generic header */
|
|
#include "cpu_comp.h" /* compiler specific CPU definitions */
|
|
|
|
|
|
/****************************************************************************************
|
|
* Local data declarations
|
|
****************************************************************************************/
|
|
/** \brief Local variable for storing the number of milliseconds that have elapsed since
|
|
* startup.
|
|
*/
|
|
static blt_int32u millisecond_counter;
|
|
|
|
/** \brief Holds the timer tick count for 1 millisecond. */
|
|
static blt_int16u millisecond_ticks;
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Initializes the polling based millisecond timer driver.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerInit(void)
|
|
{
|
|
blt_int32u dummy;
|
|
|
|
/* reset the timer configuration */
|
|
TimerReset();
|
|
/* obtain "E" access rights */
|
|
CpuEnterInitMode();
|
|
/* enable the GPT12 timer module */
|
|
GPT120_CLC.reg = 0x00000000;
|
|
/* dummy read to avoid pipeline effects */
|
|
dummy = GPT120_CLC.reg;
|
|
/* release "E" access rights */
|
|
CpuLeaveInitMode();
|
|
/* core timer 3 is used for polling millisecond events. its configuration is:
|
|
* - timer 3 works in timer mode
|
|
* - external up/down control is disabled
|
|
* - prescaler factor is 128 (Ftimer3 = BOOT_CPU_SYSTEM_SPEED_KHZ / 128)
|
|
* - up/down control bit is reset
|
|
* - alternate output function T3OUT is disabled
|
|
* - timer 3 output toggle latch (T3OTL) is set to 0
|
|
* - timer 3 run bit is set
|
|
*/
|
|
GPT120_T3CON.reg = 0x00000845;
|
|
/* reset the timer 3 register so that counter starts at 0 */
|
|
GPT120_T3.reg = 0x00000000;
|
|
/* calculate the number of timer ticks in 1 millisecond */
|
|
millisecond_ticks = ((blt_int32u)BOOT_CPU_SYSTEM_SPEED_KHZ / 128);
|
|
/* 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)
|
|
{
|
|
blt_int32u dummy;
|
|
/* revert back to timer 3 configuration reset value */
|
|
GPT120_T3CON.reg = 0x00000000;
|
|
/* revert back to timer 3 reset value */
|
|
GPT120_T3.reg = 0x00000000;
|
|
/* obtain "E" access rights */
|
|
CpuEnterInitMode();
|
|
/* disable the GPT12 timer module */
|
|
GPT120_CLC.reg = 0x00000003;
|
|
/* dummy read to avoid pipeline effects */
|
|
dummy = GPT120_CLC.reg;
|
|
/* release "E" access rights */
|
|
CpuLeaveInitMode();
|
|
} /* end of TimerReset */
|
|
|
|
|
|
/************************************************************************************//**
|
|
** \brief Updates the millisecond timer.
|
|
** \return none.
|
|
**
|
|
****************************************************************************************/
|
|
void TimerUpdate(void)
|
|
{
|
|
/* check if the millisecond event occurred */
|
|
if (GPT120_T3.reg >= millisecond_ticks)
|
|
{
|
|
GPT120_T3.reg = 0;
|
|
/* reset timer 3 register for detecting the next millisecond */
|
|
/* increment the millisecond counter */
|
|
millisecond_counter++;
|
|
}
|
|
} /*** 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 ************************************/
|