51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2017 Karl Palsson <karlp@tweak.net.au>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* This file implements some simple busy timers. They are designed to be
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* portable, not performant.
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* TIM6 is appropriated for usage.
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*/
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#include <stdint.h>
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#include <libopencm3/stm32/rcc.h>
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#include <libopencm3/stm32/timer.h>
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#include "delay.h"
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void delay_setup(void)
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{
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/* set up a microsecond free running timer for ... things... */
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rcc_periph_clock_enable(RCC_TIM6);
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/* microsecond counter */
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timer_set_prescaler(TIM6, rcc_apb1_frequency / 1000000 - 1);
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timer_set_period(TIM6, 0xffff);
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timer_one_shot_mode(TIM6);
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}
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void delay_us(uint16_t us)
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{
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TIM_ARR(TIM6) = us;
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TIM_EGR(TIM6) = TIM_EGR_UG;
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TIM_CR1(TIM6) |= TIM_CR1_CEN;
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//timer_enable_counter(TIM6);
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while (TIM_CR1(TIM6) & TIM_CR1_CEN);
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}
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