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/* *****************************************************************************
* 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 time.c
*
* @brief
*/
#include "libmaple.h"
#include "systick.h"
#include "time.h"
#define CYCLES_PER_MICROSECOND 72
#define FUDGE 42
extern volatile uint32 systick_timer_millis;
uint32 millis() {
unsigned long m;
m = systick_timer_millis;
return m;
}
void delay(unsigned long ms)
{
unsigned long start = millis();
while (millis() - start <= ms)
;
}
#if 1
void delayMicroseconds(uint32 us) {
uint32 target;
uint32 last, cur, count;
/* fudge factor hacky hack hack for function overhead */
target = us * CYCLES_PER_MICROSECOND - FUDGE;
/* Get current count */
last = systick_get_count();
cur = systick_get_count();
count = last;
while ((count-cur) <= target) {
cur = systick_get_count();
/* check for overflow */
if (cur > last) {
count += MAPLE_RELOAD_VAL;
}
last = cur;
}
}
#endif
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