tinySA/boards/ST_STM8S_DISCOVERY/board.c

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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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.
ChibiOS/RT 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "ch.h"
#include "hal.h"
/*
* TIM 2 clock after the prescaler.
*/
#define TIM2_CLOCK (SYSCLK / 16)
#define TIM2_ARR ((TIM2_CLOCK / CH_FREQUENCY) - 1)
/*
* Board initialization code.
*/
void hwinit(void) {
/*
* HAL initialization.
*/
halInit();
/*
* TIM2 initialization as system tick.
*/
CLK->PCKENR1 |= 32; /* PCKEN15, TIM2 clock source.*/
TIM2->PSCR = 4; /* Prescaler divide by 2^4=16.*/
TIM2->ARRH = (uint8_t)(TIM2_ARR >> 8);
TIM2->ARRL = (uint8_t)(TIM2_ARR);
TIM2->CNTRH = 0;
TIM2->CNTRL = 0;
TIM2->SR1 = 0;
TIM2->IER = 1; /* UIE */
TIM2->CR1 = 1; /* CEN */
}