You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
45 lines
1.3 KiB
45 lines
1.3 KiB
/*
|
|
* This file is part of the libopencm3 project.
|
|
*
|
|
* Copyright (C) 2018 Seb Holzapfel <schnommus@gmail.com>
|
|
*
|
|
* This library is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Lesser General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This library 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 Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public License
|
|
* along with this library. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <libopencm3/efm32/cmu.h>
|
|
#include <libopencm3/efm32/timer.h>
|
|
|
|
#include "delay.h"
|
|
|
|
extern const uint32_t ahb_frequency;
|
|
|
|
void delay_setup(void)
|
|
{
|
|
cmu_periph_clock_enable(CMU_TIMER2);
|
|
/* efm32hg doesn't support a nice 1us prescaler */
|
|
timer_start(TIMER2);
|
|
}
|
|
|
|
void delay_us(uint16_t us)
|
|
{
|
|
volatile uint16_t time_now = 0;
|
|
/* Convert microseconds into timer ticks */
|
|
uint16_t delay_ahb_cycles = us * (ahb_frequency / 1000000);
|
|
|
|
TIMER2_CNT = 0;
|
|
while (time_now < delay_ahb_cycles) {
|
|
time_now = TIMER2_CNT;
|
|
}
|
|
}
|
|
|