87 行
2.7 KiB
C
87 行
2.7 KiB
C
/* Teensyduino Core Library
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* http://www.pjrc.com/teensy/
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* Copyright (c) 2013 PJRC.COM, LLC.
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* Modifications by Jacob Alexander 2013-2015
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* 1. The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* 2. If the Software is incorporated into a build system that allows
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* selection among a list of target devices, then similar target
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* devices manufactured by PJRC.COM must be included in the list of
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* target devices and selectable in the same manner.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#pragma once
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// ----- System Includes -----
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#include <stdint.h>
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// ----- Macros -----
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// Convenience Macros, for delay compatibility with AVR-GCC
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#define _delay_ms(val) delay( val )
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#define _delay_us(val) delayMicroseconds( val )
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// ----- Functions -----
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// the systick interrupt is supposed to increment this at 1 kHz rate
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extern volatile uint32_t systick_millis_count;
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static inline uint32_t millis(void) __attribute__((always_inline, unused));
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static inline uint32_t millis(void)
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{
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return systick_millis_count; // single aligned 32 bit is atomic;
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}
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static inline void delayMicroseconds(uint32_t) __attribute__((always_inline, unused));
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static inline void delayMicroseconds(uint32_t usec)
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{
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#if F_CPU == 96000000
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uint32_t n = usec << 5;
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#elif F_CPU == 72000000
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uint32_t n = usec << 5; // XXX Not accurate, assembly snippet needs to be updated
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#elif F_CPU == 48000000
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uint32_t n = usec << 4;
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#elif F_CPU == 24000000
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uint32_t n = usec << 3;
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#endif
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asm volatile(
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"L_%=_delayMicroseconds:" "\n\t"
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"subs %0, #1" "\n\t"
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"bne L_%=_delayMicroseconds" "\n"
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: "+r" (n) :
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);
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}
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void yield(void) __attribute__ ((weak));
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uint32_t micros(void);
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void delay(uint32_t ms);
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