Arduino_STM32/STM32F4/cores/maple/wirish_time.h

106 lines
3.1 KiB
C

/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Perry Hung.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file wirish_time.h
* @brief Timing and delay functions.
*/
#ifndef __WIRISH_TIME_H_
#define __WIRISH_TIME_H_
#include "libmaple.h"
#include "nvic.h"
#include "systick.h"
#include "boards.h"
#define US_PER_MS 1000
/**
* Returns time (in milliseconds) since the beginning of program
* execution. On overflow, restarts at 0.
* @see micros()
*/
static inline uint32 millis(void) {
return systick_uptime();
}
/**
* Returns time (in microseconds) since the beginning of program
* execution. On overflow, restarts at 0.
* @see millis()
*/
static inline uint32 micros(void) {
uint32 ms;
uint32 cycle_cnt;
uint32 res;
do {
ms = millis();
cycle_cnt = systick_get_count();
asm volatile("nop"); //allow interrupt to fire
asm volatile("nop");
} while (ms != millis());
if(systick_check_underflow()) {
ms++;
cycle_cnt = systick_get_count();
}
/* SYSTICK_RELOAD_VAL is 1 less than the number of cycles it
actually takes to complete a SysTick reload */
res = (ms * US_PER_MS) +
(SYSTICK_RELOAD_VAL + 1 - cycle_cnt) / CYCLES_PER_MICROSECOND;
return res;
}
/**
* Delay for at least the given number of milliseconds.
*
* Interrupts, etc. may cause the actual number of milliseconds to
* exceed ms. However, this function will return no less than ms
* milliseconds from the time it is called.
*
* @param ms the number of milliseconds to delay.
* @see delayMicroseconds()
*/
void delay(unsigned long ms);
/**
* Delay for at least the given number of microseconds.
*
* Interrupts, etc. may cause the actual number of microseconds to
* exceed us. However, this function will return no less than us
* microseconds from the time it is called.
*
* @param us the number of microseconds to delay.
* @see delay()
*/
void delayMicroseconds(uint32 us);
#endif