/************************************************************************************//** * \file Source/TRICORE_TC2/timer.c * \brief Bootloader timer driver source file. * \ingroup Target_TRICORE_TC2 * \internal *---------------------------------------------------------------------------------------- * C O P Y R I G H T *---------------------------------------------------------------------------------------- * Copyright (c) 2023 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 "Stm/Std/IfxStm.h" /* STM driver */ /**************************************************************************************** * Local data declarations ****************************************************************************************/ /** \brief Local variable for storing the number of milliseconds that have elapsed since * startup. */ static blt_int32u millisecond_counter; /** \brief Buffer for storing the last value of the lower 32-bits of the free running * counter. */ static blt_int32u free_running_counter_last; /** \brief Stores the number of counts of the free running counter that equals one * millisecond. */ static blt_int32u counts_per_millisecond; /************************************************************************************//** ** \brief Initializes the polling based millisecond timer driver. ** \return none. ** ****************************************************************************************/ void TimerInit(void) { /* Reset the timer configuration. */ TimerReset(); /* Calculate the number of counts of the free running counter that equals one * millisecond. */ counts_per_millisecond = IfxStm_getFrequency(&MODULE_STM0) / 1000U; /* Initialize the last free running counter variable, which is used for delta * calculations. */ free_running_counter_last = IfxStm_getLower(&MODULE_STM0); /* 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) { /* Bring the system timer back into its reset state. */ IfxStm_resetModule(&MODULE_STM0); } /*** end of TimerReset ***/ /************************************************************************************//** ** \brief Updates the millisecond timer. ** \return none. ** ****************************************************************************************/ void TimerUpdate(void) { blt_int32u free_running_counter_now; blt_int32u delta_counts; blt_int32u ms_counts; /* Get the current value of the lower 32-bits of the free running counter. */ free_running_counter_now = IfxStm_getLower(&MODULE_STM0); /* Calculate the number of counts that passed since the detection of the last * millisecond event. Note that this calculation also works, in case the free running * counter overflowed, thanks to integer math. */ delta_counts = free_running_counter_now - free_running_counter_last; /* Did one or more milliseconds pass since the last event? */ if (delta_counts >= counts_per_millisecond) { /* Calculate how many milliseconds passed. */ ms_counts = delta_counts / counts_per_millisecond; /* Update the millisecond counter. */ millisecond_counter += ms_counts; /* Store the counter value of the last millisecond event, to detect the next one. */ free_running_counter_last += (ms_counts * counts_per_millisecond); } } /*** 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 ************************************/