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<h1>cpufunc.h</h1><a href="cpufunc_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* Copyright (c) 2010, Joerg Wunsch</span>
<a name="l00002"></a>00002 <span class="comment">   All rights reserved.</span>
<a name="l00003"></a>00003 <span class="comment"></span>
<a name="l00004"></a>00004 <span class="comment">   Redistribution and use in source and binary forms, with or without</span>
<a name="l00005"></a>00005 <span class="comment">   modification, are permitted provided that the following conditions are met:</span>
<a name="l00006"></a>00006 <span class="comment"></span>
<a name="l00007"></a>00007 <span class="comment">   * Redistributions of source code must retain the above copyright</span>
<a name="l00008"></a>00008 <span class="comment">     notice, this list of conditions and the following disclaimer.</span>
<a name="l00009"></a>00009 <span class="comment"></span>
<a name="l00010"></a>00010 <span class="comment">   * Redistributions in binary form must reproduce the above copyright</span>
<a name="l00011"></a>00011 <span class="comment">     notice, this list of conditions and the following disclaimer in</span>
<a name="l00012"></a>00012 <span class="comment">     the documentation and/or other materials provided with the</span>
<a name="l00013"></a>00013 <span class="comment">     distribution.</span>
<a name="l00014"></a>00014 <span class="comment"></span>
<a name="l00015"></a>00015 <span class="comment">   * Neither the name of the copyright holders nor the names of</span>
<a name="l00016"></a>00016 <span class="comment">     contributors may be used to endorse or promote products derived</span>
<a name="l00017"></a>00017 <span class="comment">     from this software without specific prior written permission.</span>
<a name="l00018"></a>00018 <span class="comment"></span>
<a name="l00019"></a>00019 <span class="comment">  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS &quot;AS IS&quot;</span>
<a name="l00020"></a>00020 <span class="comment">  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE</span>
<a name="l00021"></a>00021 <span class="comment">  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE</span>
<a name="l00022"></a>00022 <span class="comment">  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE</span>
<a name="l00023"></a>00023 <span class="comment">  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR</span>
<a name="l00024"></a>00024 <span class="comment">  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF</span>
<a name="l00025"></a>00025 <span class="comment">  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS</span>
<a name="l00026"></a>00026 <span class="comment">  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN</span>
<a name="l00027"></a>00027 <span class="comment">  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)</span>
<a name="l00028"></a>00028 <span class="comment">  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE</span>
<a name="l00029"></a>00029 <span class="comment">  POSSIBILITY OF SUCH DAMAGE. */</span>
<a name="l00030"></a>00030 
<a name="l00031"></a>00031 <span class="comment">/* $Id$ */</span>
<a name="l00032"></a>00032 
<a name="l00033"></a>00033 <span class="comment">/* avr/cpufunc.h - Special CPU functions */</span>
<a name="l00034"></a>00034 
<a name="l00035"></a>00035 <span class="preprocessor">#ifndef _AVR_CPUFUNC_H_</span>
<a name="l00036"></a>00036 <span class="preprocessor"></span><span class="preprocessor">#define _AVR_CPUFUNC_H_ 1</span>
<a name="l00037"></a>00037 <span class="preprocessor"></span>
<a name="l00038"></a>00038 <span class="preprocessor">#include &lt;<a class="code" href="stdint_8h.html">stdint.h</a>&gt;</span>
<a name="l00039"></a>00039 <span class="comment"></span>
<a name="l00040"></a>00040 <span class="comment">/** \file */</span><span class="comment"></span>
<a name="l00041"></a>00041 <span class="comment">/** \defgroup avr_cpufunc &lt;avr/cpufunc.h&gt;: Special AVR CPU functions</span>
<a name="l00042"></a>00042 <span class="comment">    \code #include &lt;avr/cpufunc.h&gt; \endcode</span>
<a name="l00043"></a>00043 <span class="comment"></span>
<a name="l00044"></a>00044 <span class="comment">    This header file contains macros that access special functions of</span>
<a name="l00045"></a>00045 <span class="comment">    the AVR CPU which do not fit into any of the other header files.</span>
<a name="l00046"></a>00046 <span class="comment"></span>
<a name="l00047"></a>00047 <span class="comment">*/</span>
<a name="l00048"></a>00048 
<a name="l00049"></a>00049 <span class="preprocessor">#if defined(__DOXYGEN__)</span>
<a name="l00050"></a>00050 <span class="preprocessor"></span><span class="comment">/**</span>
<a name="l00051"></a>00051 <span class="comment">   \ingroup avr_cpufunc</span>
<a name="l00052"></a>00052 <span class="comment">   \def _NOP</span>
<a name="l00053"></a>00053 <span class="comment"></span>
<a name="l00054"></a>00054 <span class="comment">   Execute a &lt;i&gt;no operation&lt;/i&gt; (NOP) CPU instruction.  This</span>
<a name="l00055"></a>00055 <span class="comment">   should not be used to implement delays, better use the functions</span>
<a name="l00056"></a>00056 <span class="comment">   from &lt;util/delay_basic.h&gt; or &lt;util/delay.h&gt; for this.  For</span>
<a name="l00057"></a>00057 <span class="comment">   debugging purposes, a NOP can be useful to have an instruction that</span>
<a name="l00058"></a>00058 <span class="comment">   is guaranteed to be not optimized away by the compiler, so it can</span>
<a name="l00059"></a>00059 <span class="comment">   always become a breakpoint in the debugger.</span>
<a name="l00060"></a>00060 <span class="comment">*/</span>
<a name="l00061"></a><a class="code" href="group__avr__cpufunc.html#ga46388d9db8422abfea56ae2323f7a77c">00061</a> <span class="preprocessor">#define _NOP()</span>
<a name="l00062"></a>00062 <span class="preprocessor"></span><span class="preprocessor">#else  </span><span class="comment">/* real code */</span>
<a name="l00063"></a>00063 <span class="preprocessor">#define _NOP() __asm__ __volatile__(&quot;nop&quot;)</span>
<a name="l00064"></a>00064 <span class="preprocessor"></span><span class="preprocessor">#endif  </span><span class="comment">/* __DOXYGEN__ */</span>
<a name="l00065"></a>00065 
<a name="l00066"></a>00066 <span class="preprocessor">#if defined(__DOXYGEN__)</span>
<a name="l00067"></a>00067 <span class="preprocessor"></span><span class="comment">/**</span>
<a name="l00068"></a>00068 <span class="comment">   \ingroup avr_cpufunc</span>
<a name="l00069"></a>00069 <span class="comment">   \def _MemoryBarrier</span>
<a name="l00070"></a>00070 <span class="comment"></span>
<a name="l00071"></a>00071 <span class="comment">   Implement a read/write &lt;i&gt;memory barrier&lt;/i&gt;.  A memory</span>
<a name="l00072"></a>00072 <span class="comment">   barrier instructs the compiler to not cache any memory data in</span>
<a name="l00073"></a>00073 <span class="comment">   registers beyond the barrier.  This can sometimes be more effective</span>
<a name="l00074"></a>00074 <span class="comment">   than blocking certain optimizations by declaring some object with a</span>
<a name="l00075"></a>00075 <span class="comment">   \c volatile qualifier.</span>
<a name="l00076"></a>00076 <span class="comment"></span>
<a name="l00077"></a>00077 <span class="comment">   See \ref optim_code_reorder for things to be taken into account</span>
<a name="l00078"></a>00078 <span class="comment">   with respect to compiler optimizations.</span>
<a name="l00079"></a>00079 <span class="comment">*/</span>
<a name="l00080"></a><a class="code" href="group__avr__cpufunc.html#ga1060ab52075a71b61c88636e204321b2">00080</a> <span class="preprocessor">#define _MemoryBarrier()</span>
<a name="l00081"></a>00081 <span class="preprocessor"></span><span class="preprocessor">#else  </span><span class="comment">/* real code */</span>
<a name="l00082"></a>00082 <span class="preprocessor">#define _MemoryBarrier() __asm__ __volatile__(&quot;&quot;:::&quot;memory&quot;)</span>
<a name="l00083"></a>00083 <span class="preprocessor"></span><span class="preprocessor">#endif  </span><span class="comment">/* __DOXYGEN__ */</span>
<a name="l00084"></a>00084 <span class="comment"></span>
<a name="l00085"></a>00085 <span class="comment">/**</span>
<a name="l00086"></a>00086 <span class="comment">   \ingroup avr_cpufunc</span>
<a name="l00087"></a>00087 <span class="comment"></span>
<a name="l00088"></a>00088 <span class="comment">   Write \a __value to Configuration Change Protected (CCP) IO register</span>
<a name="l00089"></a>00089 <span class="comment">   at \a __ioaddr.</span>
<a name="l00090"></a>00090 <span class="comment"> */</span>
<a name="l00091"></a>00091 <span class="keywordtype">void</span> <a class="code" href="group__avr__cpufunc.html#ga8092f4f9ef8cc06e720507cfc38b3e8b">ccp_write_io</a> (<a class="code" href="group__avr__stdint.html#gaba7bc1797add20fe3efdf37ced1182c5">uint8_t</a> *__ioaddr, <a class="code" href="group__avr__stdint.html#gaba7bc1797add20fe3efdf37ced1182c5">uint8_t</a> __value);
<a name="l00092"></a>00092 
<a name="l00093"></a>00093 <span class="preprocessor">#endif </span><span class="comment">/* _AVR_CPUFUNC_H_ */</span>
</pre></div></div>
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