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Diffstat (limited to 'delay.h')
| -rw-r--r-- | delay.h | 264 |
1 files changed, 0 insertions, 264 deletions
diff --git a/delay.h b/delay.h deleted file mode 100644 index 0a2ed8e..0000000 --- a/delay.h +++ /dev/null @@ -1,264 +0,0 @@ -/* Copyright (c) 2002, Marek Michalkiewicz - Copyright (c) 2004,2005,2007 Joerg Wunsch - Copyright (c) 2007 Florin-Viorel Petrov - 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.h.in 2251 2011-09-14 08:20:33Z joerg_wunsch $ */ - -#ifndef _UTIL_DELAY_H_ -#define _UTIL_DELAY_H_ 1 - -#ifndef __HAS_DELAY_CYCLES -#define __HAS_DELAY_CYCLES 1 -#endif - -#include <inttypes.h> -#include "delay_basic.h" -#include <math.h> - -/** \file */ -/** \defgroup util_delay <util/delay.h>: Convenience functions for busy-wait delay loops - \code - #define F_CPU 1000000UL // 1 MHz - //#define F_CPU 14.7456E6 - #include <util/delay.h> - \endcode - - \note As an alternative method, it is possible to pass the - F_CPU macro down to the compiler from the Makefile. - Obviously, in that case, no \c \#define statement should be - used. - - The functions in this header file are wrappers around the basic - busy-wait functions from <util/delay_basic.h>. They are meant as - convenience functions where actual time values can be specified - rather than a number of cycles to wait for. The idea behind is - that compile-time constant expressions will be eliminated by - compiler optimization so floating-point expressions can be used - to calculate the number of delay cycles needed based on the CPU - frequency passed by the macro F_CPU. - - \note In order for these functions to work as intended, compiler - optimizations <em>must</em> be enabled, and the delay time - <em>must</em> be an expression that is a known constant at - compile-time. If these requirements are not met, the resulting - delay will be much longer (and basically unpredictable), and - applications that otherwise do not use floating-point calculations - will experience severe code bloat by the floating-point library - routines linked into the application. - - The functions available allow the specification of microsecond, and - millisecond delays directly, using the application-supplied macro - F_CPU as the CPU clock frequency (in Hertz). - -*/ - -#if !defined(__DOXYGEN__) -static inline void delay_us(double __us) __attribute__((always_inline)); -static inline void delay_ms(double __ms) __attribute__((always_inline)); -#endif - -#ifndef F_CPU -/* prevent compiler error by supplying a default */ -# warning "F_CPU not defined for <util/delay.h>" -# define F_CPU 1000000UL -#endif - -#ifndef __OPTIMIZE__ -# warning "Compiler optimizations disabled; functions from <util/delay.h> won't work as designed" -#endif - -#if __HAS_DELAY_CYCLES && defined(__OPTIMIZE__) && \ - !defined(__DELAY_BACKWARD_COMPATIBLE__) && \ - __STDC_HOSTED__ -# include <math.h> -#endif - -/** - \ingroup util_delay - - Perform a delay of \c __ms milliseconds, using delay_loop_2(). - - The macro F_CPU is supposed to be defined to a - constant defining the CPU clock frequency (in Hertz). - - The maximal possible delay is 262.14 ms / F_CPU in MHz. - - When the user request delay which exceed the maximum possible one, - delay_ms() provides a decreased resolution functionality. In this - mode delay_ms() will work with a resolution of 1/10 ms, providing - delays up to 6.5535 seconds (independent from CPU frequency). The - user will not be informed about decreased resolution. - - If the avr-gcc toolchain has __builtin_avr_delay_cycles(unsigned long) - support, maximal possible delay is 4294967.295 ms/ F_CPU in MHz. For - values greater than the maximal possible delay, overflows results in - no delay i.e., 0ms. - - Conversion of __us into clock cycles may not always result in integer. - By default, the clock cycles rounded up to next integer. This ensures that - the user gets atleast __us microseconds of delay. - - Alternatively, user can define __DELAY_ROUND_DOWN__ and __DELAY_ROUND_CLOSEST__ - to round down and round to closest integer. - - Note: The new implementation of delay_ms(double __ms) with - __builtin_avr_delay_cycles(unsigned long) support is not backward compatible. - User can define __DELAY_BACKWARD_COMPATIBLE__ to get a backward compatible delay. - Also, the backward compatible - algorithm will be chosen if the code is compiled in a <em>freestanding - environment</em> (GCC option \c -ffreestanding), as the math functions - required for rounding are not available to the compiler then. - - */ -static inline void -delay_ms(double __ms) -{ - double __tmp ; -#if __HAS_DELAY_CYCLES && defined(__OPTIMIZE__) && \ - !defined(__DELAY_BACKWARD_COMPATIBLE__) && \ - __STDC_HOSTED__ - uint32_t __ticks_dc; - extern void __builtin_avr_delay_cycles(unsigned long); - __tmp = ((F_CPU) / 1e3) * __ms; - - #if defined(__DELAY_ROUND_DOWN__) - __ticks_dc = (uint32_t)fabs(__tmp); - - #elif defined(__DELAY_ROUND_CLOSEST__) - __ticks_dc = (uint32_t)(fabs(__tmp)+0.5); - - #else - //round up by default - __ticks_dc = (uint32_t)(ceil(fabs(__tmp))); - #endif - - __builtin_avr_delay_cycles(__ticks_dc); - -#else - uint16_t __ticks; - __tmp = ((F_CPU) / 4e3) * __ms; - if (__tmp < 1.0) - __ticks = 1; - else if (__tmp > 65535) - { - // __ticks = requested delay in 1/10 ms - __ticks = (uint16_t) (__ms * 10.0); - while(__ticks) - { - // wait 1/10 ms - delay_loop_2(((F_CPU) / 4e3) / 10); - __ticks --; - } - return; - } - else - __ticks = (uint16_t)__tmp; - delay_loop_2(__ticks); -#endif -} - -/** - \ingroup util_delay - - Perform a delay of \c __us microseconds, using delay_loop_1(). - - The macro F_CPU is supposed to be defined to a - constant defining the CPU clock frequency (in Hertz). - - The maximal possible delay is 768 us / F_CPU in MHz. - - If the user requests a delay greater than the maximal possible one, - delay_us() will automatically call delay_ms() instead. The user - will not be informed about this case. - - If the avr-gcc toolchain has __builtin_avr_delay_cycles(unsigned long) - support, maximal possible delay is 4294967.295 us/ F_CPU in MHz. For - values greater than the maximal possible delay, overflow results in - no delay i.e., 0us. - - Conversion of __us into clock cycles may not always result in integer. - By default, the clock cycles rounded up to next integer. This ensures that - the user gets atleast __us microseconds of delay. - - Alternatively, user can define __DELAY_ROUND_DOWN__ and __DELAY_ROUND_CLOSEST__ - to round down and round to closest integer. - - Note: The new implementation of delay_us(double __us) with - __builtin_avr_delay_cycles(unsigned long) support is not backward compatible. - User can define __DELAY_BACKWARD_COMPATIBLE__ to get a backward compatible delay. - Also, the backward compatible - algorithm will be chosen if the code is compiled in a <em>freestanding - environment</em> (GCC option \c -ffreestanding), as the math functions - required for rounding are not available to the compiler then. - - */ -static inline void -delay_us(double __us) -{ - double __tmp ; -#if __HAS_DELAY_CYCLES && defined(__OPTIMIZE__) && \ - !defined(__DELAY_BACKWARD_COMPATIBLE__) && \ - __STDC_HOSTED__ - uint32_t __ticks_dc; - extern void __builtin_avr_delay_cycles(unsigned long); - __tmp = ((F_CPU) / 1e6) * __us; - - #if defined(__DELAY_ROUND_DOWN__) - __ticks_dc = (uint32_t)fabs(__tmp); - - #elif defined(__DELAY_ROUND_CLOSEST__) - __ticks_dc = (uint32_t)(fabs(__tmp)+0.5); - - #else - //round up by default - __ticks_dc = (uint32_t)(ceil(fabs(__tmp))); - #endif - - __builtin_avr_delay_cycles(__ticks_dc); - -#else - uint8_t __ticks; - __tmp = ((F_CPU) / 3e6) * __us; - if (__tmp < 1.0) - __ticks = 1; - else if (__tmp > 255) - { - delay_ms(__us / 1000.0); - return; - } - else - __ticks = (uint8_t)__tmp; - delay_loop_1(__ticks); -#endif -} - - -#endif /* _UTIL_DELAY_H_ */ |