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Diffstat (limited to 'delay_basic.h')
| -rw-r--r-- | delay_basic.h | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/delay_basic.h b/delay_basic.h deleted file mode 100644 index 199386f..0000000 --- a/delay_basic.h +++ /dev/null @@ -1,113 +0,0 @@ -/* Copyright (c) 2002, Marek Michalkiewicz - Copyright (c) 2007 Joerg Wunsch - All rights reserved. - - Redistribution and use in source and binary forms, with or without - modification, are permitted provided that the following conditions are met: - - * Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. - - * Redistributions in binary form must reproduce the above copyright - notice, this list of conditions and the following disclaimer in - the documentation and/or other materials provided with the - distribution. - - * Neither the name of the copyright holders nor the names of - contributors may be used to endorse or promote products derived - from this software without specific prior written permission. - - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE - LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - POSSIBILITY OF SUCH DAMAGE. */ - -/* $Id: delay_basic.h 2143 2010-06-08 21:19:51Z joerg_wunsch $ */ - -#ifndef _UTIL_DELAY_BASIC_H_ -#define _UTIL_DELAY_BASIC_H_ 1 - -#include <inttypes.h> - -#if !defined(__DOXYGEN__) -static inline void delay_loop_1(uint8_t __count) __attribute__((always_inline)); -static inline void delay_loop_2(uint16_t __count) __attribute__((always_inline)); -#endif - -/** \file */ -/** \defgroup util_delay_basic <util/delay_basic.h>: Basic busy-wait delay loops - \code - #include <util/delay_basic.h> - \endcode - - The functions in this header file implement simple delay loops - that perform a busy-waiting. They are typically used to - facilitate short delays in the program execution. They are - implemented as count-down loops with a well-known CPU cycle - count per loop iteration. As such, no other processing can - occur simultaneously. It should be kept in mind that the - functions described here do not disable interrupts. - - In general, for long delays, the use of hardware timers is - much preferrable, as they free the CPU, and allow for - concurrent processing of other events while the timer is - running. However, in particular for very short delays, the - overhead of setting up a hardware timer is too much compared - to the overall delay time. - - Two inline functions are provided for the actual delay algorithms. - -*/ - -/** \ingroup util_delay_basic - - Delay loop using an 8-bit counter \c __count, so up to 256 - iterations are possible. (The value 256 would have to be passed - as 0.) The loop executes three CPU cycles per iteration, not - including the overhead the compiler needs to setup the counter - register. - - Thus, at a CPU speed of 1 MHz, delays of up to 768 microseconds - can be achieved. -*/ -static inline void -delay_loop_1(uint8_t __count) -{ - __asm__ volatile ( - "1: dec %0" "\n\t" - "brne 1b" - : "=r" (__count) - : "0" (__count) - ); -} - -/** \ingroup util_delay_basic - - Delay loop using a 16-bit counter \c __count, so up to 65536 - iterations are possible. (The value 65536 would have to be - passed as 0.) The loop executes four CPU cycles per iteration, - not including the overhead the compiler requires to setup the - counter register pair. - - Thus, at a CPU speed of 1 MHz, delays of up to about 262.1 - milliseconds can be achieved. - */ -static inline void -delay_loop_2(uint16_t __count) -{ - __asm__ volatile ( - "1: sbiw %0,1" "\n\t" - "brne 1b" - : "=w" (__count) - : "0" (__count) - ); -} - -#endif /* _UTIL_DELAY_BASIC_H_ */ |