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<title>avr-libc: <util/parity.h>: Parity bit generation</title>
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<h1><util/parity.h>: Parity bit generation</h1><table border="0" cellpadding="0" cellspacing="0">
<tr><td colspan="2"><h2>Defines</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">#define </td><td class="memItemRight" valign="bottom"><a class="el" href="group__util__parity.html#ga4180eaa9b8f27f8efc589f3a3ba1724c">parity_even_bit</a>(val)</td></tr>
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<hr/><a name="_details"></a><h2>Detailed Description</h2>
<div class="fragment"><pre class="fragment"><span class="preprocessor"> #include <<a class="code" href="parity_8h.html">util/parity.h</a>></span>
</pre></div><p>This header file contains optimized assembler code to calculate the parity bit for a byte. </p>
<hr/><h2>Define Documentation</h2>
<a class="anchor" id="ga4180eaa9b8f27f8efc589f3a3ba1724c"></a><!-- doxytag: member="parity.h::parity_even_bit" ref="ga4180eaa9b8f27f8efc589f3a3ba1724c" args="(val)" -->
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<td class="memname">#define parity_even_bit</td>
<td>(</td>
<td class="paramtype">val </td>
<td class="paramname"></td>
<td> ) </td>
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<b>Value:</b><div class="fragment"><pre class="fragment">(__extension__({ \
<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> __t; \
__asm__ ( \
<span class="stringliteral">"mov __tmp_reg__,%0"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"swap %0"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"eor %0,__tmp_reg__"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"mov __tmp_reg__,%0"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"lsr %0"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"lsr %0"</span> <span class="stringliteral">"\n\t"</span> \
<span class="stringliteral">"eor %0,__tmp_reg__"</span> \
: <span class="stringliteral">"=r"</span> (__t) \
: <span class="stringliteral">"0"</span> ((<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>)(val)) \
: <span class="stringliteral">"r0"</span> \
); \
(((__t + 1) >> 1) & 1); \
}))
</pre></div><dl class="return"><dt><b>Returns:</b></dt><dd>1 if <code>val</code> has an odd number of bits set. </dd></dl>
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<p><center>Automatically generated by Doxygen 1.6.1 on 30 Nov 2009.</center></p>
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