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<h1>gr_pfb_clock_sync_fff.h</h1><a href="gr__pfb__clock__sync__fff_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* -*- c++ -*- */</span>
<a name="l00002"></a>00002 <span class="comment">/*</span>
<a name="l00003"></a>00003 <span class="comment"> * Copyright 2009,2010 Free Software Foundation, Inc.</span>
<a name="l00004"></a>00004 <span class="comment"> * </span>
<a name="l00005"></a>00005 <span class="comment"> * This file is part of GNU Radio</span>
<a name="l00006"></a>00006 <span class="comment"> * </span>
<a name="l00007"></a>00007 <span class="comment"> * GNU Radio is free software; you can redistribute it and/or modify</span>
<a name="l00008"></a>00008 <span class="comment"> * it under the terms of the GNU General Public License as published by</span>
<a name="l00009"></a>00009 <span class="comment"> * the Free Software Foundation; either version 3, or (at your option)</span>
<a name="l00010"></a>00010 <span class="comment"> * any later version.</span>
<a name="l00011"></a>00011 <span class="comment"> * </span>
<a name="l00012"></a>00012 <span class="comment"> * GNU Radio is distributed in the hope that it will be useful,</span>
<a name="l00013"></a>00013 <span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<a name="l00014"></a>00014 <span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span>
<a name="l00015"></a>00015 <span class="comment"> * GNU General Public License for more details.</span>
<a name="l00016"></a>00016 <span class="comment"> * </span>
<a name="l00017"></a>00017 <span class="comment"> * You should have received a copy of the GNU General Public License</span>
<a name="l00018"></a>00018 <span class="comment"> * along with GNU Radio; see the file COPYING. If not, write to</span>
<a name="l00019"></a>00019 <span class="comment"> * the Free Software Foundation, Inc., 51 Franklin Street,</span>
<a name="l00020"></a>00020 <span class="comment"> * Boston, MA 02110-1301, USA.</span>
<a name="l00021"></a>00021 <span class="comment"> */</span>
<a name="l00022"></a>00022
<a name="l00023"></a>00023
<a name="l00024"></a>00024 <span class="preprocessor">#ifndef INCLUDED_GR_PFB_CLOCK_SYNC_FFF_H</span>
<a name="l00025"></a>00025 <span class="preprocessor"></span><span class="preprocessor">#define INCLUDED_GR_PFB_CLOCK_SYNC_FFF_H</span>
<a name="l00026"></a>00026 <span class="preprocessor"></span>
<a name="l00027"></a>00027 <span class="preprocessor">#include <<a class="code" href="gr__block_8h.html">gr_block.h</a>></span>
<a name="l00028"></a>00028
<a name="l00029"></a>00029 <span class="keyword">class </span><a class="code" href="classgr__pfb__clock__sync__fff.html" title="Timing synchronizer using polyphase filterbanks.">gr_pfb_clock_sync_fff</a>;
<a name="l00030"></a>00030 <span class="keyword">typedef</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">boost::shared_ptr<gr_pfb_clock_sync_fff></a> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_pfb_clock_sync_fff_sptr</a>;
<a name="l00031"></a>00031 <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_pfb_clock_sync_fff_sptr</a> <a class="code" href="gr__pfb__clock__sync__fff_8h.html#a82d465c8341595c038369d0aabbf10e3">gr_make_pfb_clock_sync_fff</a> (<span class="keywordtype">double</span> sps, <span class="keywordtype">float</span> gain,
<a name="l00032"></a>00032 <span class="keyword">const</span> <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &<a class="code" href="interpolator__taps_8h.html#a30bf032e13c2a9fc4a98e14e390cd65a">taps</a>,
<a name="l00033"></a>00033 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> filter_size=32,
<a name="l00034"></a>00034 <span class="keywordtype">float</span> init_phase=0,
<a name="l00035"></a>00035 <span class="keywordtype">float</span> max_rate_deviation=1.5);
<a name="l00036"></a>00036
<a name="l00037"></a>00037 <span class="keyword">class </span><a class="code" href="classgr__fir__fff.html" title="Abstract class for FIR with float input, float output and float tapsThis is the abstract...">gr_fir_fff</a>;
<a name="l00038"></a>00038 <span class="comment"></span>
<a name="l00039"></a>00039 <span class="comment">/*!</span>
<a name="l00040"></a>00040 <span class="comment"> * \class gr_pfb_clock_sync_fff</span>
<a name="l00041"></a>00041 <span class="comment"> *</span>
<a name="l00042"></a>00042 <span class="comment"> * \brief Timing synchronizer using polyphase filterbanks</span>
<a name="l00043"></a>00043 <span class="comment"> *</span>
<a name="l00044"></a>00044 <span class="comment"> * \ingroup filter_blk</span>
<a name="l00045"></a>00045 <span class="comment"> * </span>
<a name="l00046"></a>00046 <span class="comment"> * This block performs timing synchronization for PAM signals by minimizing the</span>
<a name="l00047"></a>00047 <span class="comment"> * derivative of the filtered signal, which in turn maximizes the SNR and </span>
<a name="l00048"></a>00048 <span class="comment"> * minimizes ISI.</span>
<a name="l00049"></a>00049 <span class="comment"> *</span>
<a name="l00050"></a>00050 <span class="comment"> * This approach works by setting up two filterbanks; one filterbanke contains the </span>
<a name="l00051"></a>00051 <span class="comment"> * signal's pulse shaping matched filter (such as a root raised cosine filter),</span>
<a name="l00052"></a>00052 <span class="comment"> * where each branch of the filterbank contains a different phase of the filter.</span>
<a name="l00053"></a>00053 <span class="comment"> * The second filterbank contains the derivatives of the filters in the first </span>
<a name="l00054"></a>00054 <span class="comment"> * filterbank. Thinking of this in the time domain, the first filterbank contains</span>
<a name="l00055"></a>00055 <span class="comment"> * filters that have a sinc shape to them. We want to align the output signal to</span>
<a name="l00056"></a>00056 <span class="comment"> * be sampled at exactly the peak of the sinc shape. The derivative of the sinc</span>
<a name="l00057"></a>00057 <span class="comment"> * contains a zero at the maximum point of the sinc (sinc(0) = 1, sinc(0)' = 0).</span>
<a name="l00058"></a>00058 <span class="comment"> * Furthermore, the region around the zero point is relatively linear. We make</span>
<a name="l00059"></a>00059 <span class="comment"> * use of this fact to generate the error signal.</span>
<a name="l00060"></a>00060 <span class="comment"> *</span>
<a name="l00061"></a>00061 <span class="comment"> * If the signal out of the derivative filters is d_i[n] for the ith filter, and</span>
<a name="l00062"></a>00062 <span class="comment"> * the output of the matched filter is x_i[n], we calculate the error as:</span>
<a name="l00063"></a>00063 <span class="comment"> * e[n] = (Re{x_i[n]} * Re{d_i[n]} + Im{x_i[n]} * Im{d_i[n]}) / 2.0</span>
<a name="l00064"></a>00064 <span class="comment"> * This equation averages the error in the real and imaginary parts. There are two</span>
<a name="l00065"></a>00065 <span class="comment"> * reasons we multiply by the signal itself. First, if the symbol could be positive</span>
<a name="l00066"></a>00066 <span class="comment"> * or negative going, but we want the error term to always tell us to go in the </span>
<a name="l00067"></a>00067 <span class="comment"> * same direction depending on which side of the zero point we are on. The sign of</span>
<a name="l00068"></a>00068 <span class="comment"> * x_i[n] adjusts the error term to do this. Second, the magnitude of x_i[n] scales</span>
<a name="l00069"></a>00069 <span class="comment"> * the error term depending on the symbol's amplitude, so larger signals give us</span>
<a name="l00070"></a>00070 <span class="comment"> * a stronger error term because we have more confidence in that symbol's value.</span>
<a name="l00071"></a>00071 <span class="comment"> * Using the magnitude of x_i[n] instead of just the sign is especially good for</span>
<a name="l00072"></a>00072 <span class="comment"> * signals with low SNR.</span>
<a name="l00073"></a>00073 <span class="comment"> *</span>
<a name="l00074"></a>00074 <span class="comment"> * The error signal, e[n], gives us a value proportional to how far away from the zero</span>
<a name="l00075"></a>00075 <span class="comment"> * point we are in the derivative signal. We want to drive this value to zero, so we</span>
<a name="l00076"></a>00076 <span class="comment"> * set up a second order loop. We have two variables for this loop; d_k is the filter</span>
<a name="l00077"></a>00077 <span class="comment"> * number in the filterbank we are on and d_rate is the rate which we travel through</span>
<a name="l00078"></a>00078 <span class="comment"> * the filters in the steady state. That is, due to the natural clock differences between</span>
<a name="l00079"></a>00079 <span class="comment"> * the transmitter and receiver, d_rate represents that difference and would traverse</span>
<a name="l00080"></a>00080 <span class="comment"> * the filter phase paths to keep the receiver locked. Thinking of this as a second-order</span>
<a name="l00081"></a>00081 <span class="comment"> * PLL, the d_rate is the frequency and d_k is the phase. So we update d_rate and d_k</span>
<a name="l00082"></a>00082 <span class="comment"> * using the standard loop equations based on two error signals, d_alpha and d_beta.</span>
<a name="l00083"></a>00083 <span class="comment"> * We have these two values set based on each other for a critically damped system, so in</span>
<a name="l00084"></a>00084 <span class="comment"> * the block constructor, we just ask for "gain," which is d_alpha while d_beta is</span>
<a name="l00085"></a>00085 <span class="comment"> * equal to (gain^2)/4.</span>
<a name="l00086"></a>00086 <span class="comment"> *</span>
<a name="l00087"></a>00087 <span class="comment"> * The clock sync block needs to know the number of samples per second (sps), because it</span>
<a name="l00088"></a>00088 <span class="comment"> * only returns a single point representing the sample. The sps can be any positive real</span>
<a name="l00089"></a>00089 <span class="comment"> * number and does not need to be an integer. The filter taps must also be specified. The</span>
<a name="l00090"></a>00090 <span class="comment"> * taps are generated by first conceiving of the prototype filter that would be the signal's</span>
<a name="l00091"></a>00091 <span class="comment"> * matched filter. Then interpolate this by the number of filters in the filterbank. These</span>
<a name="l00092"></a>00092 <span class="comment"> * are then distributed among all of the filters. So if the prototype filter was to have</span>
<a name="l00093"></a>00093 <span class="comment"> * 45 taps in it, then each path of the filterbank will also have 45 taps. This is easily</span>
<a name="l00094"></a>00094 <span class="comment"> * done by building the filter with the sample rate multiplied by the number of filters</span>
<a name="l00095"></a>00095 <span class="comment"> * to use.</span>
<a name="l00096"></a>00096 <span class="comment"> *</span>
<a name="l00097"></a>00097 <span class="comment"> * The number of filters can also be set and defaults to 32. With 32 filters, you get a</span>
<a name="l00098"></a>00098 <span class="comment"> * good enough resolution in the phase to produce very small, almost unnoticeable, ISI.</span>
<a name="l00099"></a>00099 <span class="comment"> * Going to 64 filters can reduce this more, but after that there is very little gained</span>
<a name="l00100"></a>00100 <span class="comment"> * for the extra complexity.</span>
<a name="l00101"></a>00101 <span class="comment"> *</span>
<a name="l00102"></a>00102 <span class="comment"> * The initial phase is another settable parameter and refers to the filter path the</span>
<a name="l00103"></a>00103 <span class="comment"> * algorithm initially looks at (i.e., d_k starts at init_phase). This value defaults </span>
<a name="l00104"></a>00104 <span class="comment"> * to zero, but it might be useful to start at a different phase offset, such as the mid-</span>
<a name="l00105"></a>00105 <span class="comment"> * point of the filters.</span>
<a name="l00106"></a>00106 <span class="comment"> *</span>
<a name="l00107"></a>00107 <span class="comment"> * The final parameter is the max_rate_devitation, which defaults to 1.5. This is how far</span>
<a name="l00108"></a>00108 <span class="comment"> * we allow d_rate to swing, positive or negative, from 0. Constraining the rate can help</span>
<a name="l00109"></a>00109 <span class="comment"> * keep the algorithm from walking too far away to lock during times when there is no signal.</span>
<a name="l00110"></a>00110 <span class="comment"> *</span>
<a name="l00111"></a>00111 <span class="comment"> */</span>
<a name="l00112"></a>00112
<a name="l00113"></a><a class="code" href="classgr__pfb__clock__sync__fff.html">00113</a> <span class="keyword">class </span><a class="code" href="classgr__pfb__clock__sync__fff.html" title="Timing synchronizer using polyphase filterbanks.">gr_pfb_clock_sync_fff</a> : <span class="keyword">public</span> <a class="code" href="classgr__block.html" title="The abstract base class for all &#39;terminal&#39; processing blocks.A signal processing...">gr_block</a>
<a name="l00114"></a>00114 {
<a name="l00115"></a>00115 <span class="keyword">private</span>:<span class="comment"></span>
<a name="l00116"></a>00116 <span class="comment"> /*!</span>
<a name="l00117"></a>00117 <span class="comment"> * Build the polyphase filterbank timing synchronizer.</span>
<a name="l00118"></a>00118 <span class="comment"> * \param sps (double) The number of samples per second in the incoming signal</span>
<a name="l00119"></a>00119 <span class="comment"> * \param gain (float) The alpha gain of the control loop; beta = (gain^2)/4 by default.</span>
<a name="l00120"></a>00120 <span class="comment"> * \param taps (vector<int>) The filter taps.</span>
<a name="l00121"></a>00121 <span class="comment"> * \param filter_size (uint) The number of filters in the filterbank (default = 32).</span>
<a name="l00122"></a>00122 <span class="comment"> * \param init_phase (float) The initial phase to look at, or which filter to start </span>
<a name="l00123"></a>00123 <span class="comment"> * with (default = 0).</span>
<a name="l00124"></a>00124 <span class="comment"> * \param max_rate_deviation (float) Distance from 0 d_rate can get (default = 1.5).</span>
<a name="l00125"></a>00125 <span class="comment"> *</span>
<a name="l00126"></a>00126 <span class="comment"> */</span>
<a name="l00127"></a>00127 <span class="keyword">friend</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_pfb_clock_sync_fff_sptr</a> <a class="code" href="classgr__pfb__clock__sync__fff.html#a1af63daa9e28fe0912811ed2531e18ab">gr_make_pfb_clock_sync_fff</a> (<span class="keywordtype">double</span> sps, <span class="keywordtype">float</span> gain,
<a name="l00128"></a>00128 <span class="keyword">const</span> <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &<a class="code" href="interpolator__taps_8h.html#a30bf032e13c2a9fc4a98e14e390cd65a">taps</a>,
<a name="l00129"></a>00129 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> filter_size,
<a name="l00130"></a>00130 <span class="keywordtype">float</span> init_phase,
<a name="l00131"></a>00131 <span class="keywordtype">float</span> max_rate_deviation);
<a name="l00132"></a>00132
<a name="l00133"></a>00133 <span class="keywordtype">bool</span> d_updated;
<a name="l00134"></a>00134 <span class="keywordtype">double</span> d_sps;
<a name="l00135"></a>00135 <span class="keywordtype">double</span> d_sample_num;
<a name="l00136"></a>00136 <span class="keywordtype">float</span> d_alpha;
<a name="l00137"></a>00137 <span class="keywordtype">float</span> d_beta;
<a name="l00138"></a>00138 <span class="keywordtype">int</span> d_nfilters;
<a name="l00139"></a>00139 <a class="code" href="classstd_1_1vector.html">std::vector<gr_fir_fff*></a> d_filters;
<a name="l00140"></a>00140 <a class="code" href="classstd_1_1vector.html">std::vector<gr_fir_fff*></a> d_diff_filters;
<a name="l00141"></a>00141 <a class="code" href="classstd_1_1vector.html" title="vector documentation stub">std::vector< std::vector<float></a> > d_taps;
<a name="l00142"></a>00142 <a class="code" href="classstd_1_1vector.html" title="vector documentation stub">std::vector< std::vector<float></a> > d_dtaps;
<a name="l00143"></a>00143 <span class="keywordtype">float</span> d_k;
<a name="l00144"></a>00144 <span class="keywordtype">float</span> d_rate;
<a name="l00145"></a>00145 <span class="keywordtype">float</span> d_rate_i;
<a name="l00146"></a>00146 <span class="keywordtype">float</span> d_rate_f;
<a name="l00147"></a>00147 <span class="keywordtype">float</span> d_max_dev;
<a name="l00148"></a>00148 <span class="keywordtype">int</span> d_filtnum;
<a name="l00149"></a>00149 <span class="keywordtype">int</span> d_taps_per_filter;
<a name="l00150"></a>00150 <span class="comment"></span>
<a name="l00151"></a>00151 <span class="comment"> /*!</span>
<a name="l00152"></a>00152 <span class="comment"> * Build the polyphase filterbank timing synchronizer.</span>
<a name="l00153"></a>00153 <span class="comment"> */</span>
<a name="l00154"></a>00154 <a class="code" href="classgr__pfb__clock__sync__fff.html" title="Timing synchronizer using polyphase filterbanks.">gr_pfb_clock_sync_fff</a> (<span class="keywordtype">double</span> sps, <span class="keywordtype">float</span> gain,
<a name="l00155"></a>00155 <span class="keyword">const</span> <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &taps,
<a name="l00156"></a>00156 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> filter_size,
<a name="l00157"></a>00157 <span class="keywordtype">float</span> init_phase,
<a name="l00158"></a>00158 <span class="keywordtype">float</span> max_rate_deviation);
<a name="l00159"></a>00159
<a name="l00160"></a>00160 <span class="keywordtype">void</span> create_diff_taps(<span class="keyword">const</span> <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &newtaps,
<a name="l00161"></a>00161 <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &difftaps);
<a name="l00162"></a>00162
<a name="l00163"></a>00163 <span class="keyword">public</span>:
<a name="l00164"></a>00164 <a class="code" href="classgr__pfb__clock__sync__fff.html#a46f50550c8146aae5338f3498a3f53c1">~gr_pfb_clock_sync_fff</a> ();
<a name="l00165"></a>00165 <span class="comment"></span>
<a name="l00166"></a>00166 <span class="comment"> /*!</span>
<a name="l00167"></a>00167 <span class="comment"> * Resets the filterbank's filter taps with the new prototype filter</span>
<a name="l00168"></a>00168 <span class="comment"> */</span>
<a name="l00169"></a>00169 <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#a40c6bac043105cb654f7631c5707e632">set_taps</a> (<span class="keyword">const</span> <a class="code" href="classstd_1_1vector.html">std::vector<float></a> &taps,
<a name="l00170"></a>00170 <a class="code" href="classstd_1_1vector.html" title="vector documentation stub">std::vector</a>< <a class="code" href="classstd_1_1vector.html">std::vector<float></a> > &ourtaps,
<a name="l00171"></a>00171 <a class="code" href="classstd_1_1vector.html">std::vector<gr_fir_fff*></a> &ourfilter);
<a name="l00172"></a>00172 <span class="comment"></span>
<a name="l00173"></a>00173 <span class="comment"> /*!</span>
<a name="l00174"></a>00174 <span class="comment"> * Returns the taps of the matched filter</span>
<a name="l00175"></a>00175 <span class="comment"> */</span>
<a name="l00176"></a>00176 <a class="code" href="classstd_1_1vector.html">std::vector<float></a> <a class="code" href="classgr__pfb__clock__sync__fff.html#a781015481acf7369771b08424e2df4dd">channel_taps</a>(<span class="keywordtype">int</span> channel);
<a name="l00177"></a>00177 <span class="comment"></span>
<a name="l00178"></a>00178 <span class="comment"> /*!</span>
<a name="l00179"></a>00179 <span class="comment"> * Returns the taps in the derivative filter</span>
<a name="l00180"></a>00180 <span class="comment"> */</span>
<a name="l00181"></a>00181 <a class="code" href="classstd_1_1vector.html">std::vector<float></a> <a class="code" href="classgr__pfb__clock__sync__fff.html#a3aab38d6b28b8ea360ec170af04f6ef2">diff_channel_taps</a>(<span class="keywordtype">int</span> channel);
<a name="l00182"></a>00182 <span class="comment"></span>
<a name="l00183"></a>00183 <span class="comment"> /*!</span>
<a name="l00184"></a>00184 <span class="comment"> * Print all of the filterbank taps to screen.</span>
<a name="l00185"></a>00185 <span class="comment"> */</span>
<a name="l00186"></a>00186 <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#a294683479b8b5b1cd0a99b4b3ba42979">print_taps</a>();
<a name="l00187"></a>00187 <span class="comment"></span>
<a name="l00188"></a>00188 <span class="comment"> /*!</span>
<a name="l00189"></a>00189 <span class="comment"> * Print all of the filterbank taps of the derivative filter to screen.</span>
<a name="l00190"></a>00190 <span class="comment"> */</span>
<a name="l00191"></a>00191 <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#acabea76b62122a2ba4a8b5019c63b643">print_diff_taps</a>();
<a name="l00192"></a>00192 <span class="comment"></span>
<a name="l00193"></a>00193 <span class="comment"> /*!</span>
<a name="l00194"></a>00194 <span class="comment"> * Set the gain value alpha for the control loop</span>
<a name="l00195"></a>00195 <span class="comment"> */</span>
<a name="l00196"></a><a class="code" href="classgr__pfb__clock__sync__fff.html#a8484ba244bb2d33a654373206a7aa66f">00196</a> <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#a8484ba244bb2d33a654373206a7aa66f">set_alpha</a>(<span class="keywordtype">float</span> alpha)
<a name="l00197"></a>00197 {
<a name="l00198"></a>00198 d_alpha = alpha;
<a name="l00199"></a>00199 }
<a name="l00200"></a>00200 <span class="comment"></span>
<a name="l00201"></a>00201 <span class="comment"> /*!</span>
<a name="l00202"></a>00202 <span class="comment"> * Set the gain value beta for the control loop</span>
<a name="l00203"></a>00203 <span class="comment"> */</span>
<a name="l00204"></a><a class="code" href="classgr__pfb__clock__sync__fff.html#ab08281a8d5b9377fe35d397d5224d739">00204</a> <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#ab08281a8d5b9377fe35d397d5224d739">set_beta</a>(<span class="keywordtype">float</span> beta)
<a name="l00205"></a>00205 {
<a name="l00206"></a>00206 d_beta = beta;
<a name="l00207"></a>00207 }
<a name="l00208"></a>00208 <span class="comment"></span>
<a name="l00209"></a>00209 <span class="comment"> /*!</span>
<a name="l00210"></a>00210 <span class="comment"> * Set the maximum deviation from 0 d_rate can have</span>
<a name="l00211"></a>00211 <span class="comment"> */</span>
<a name="l00212"></a><a class="code" href="classgr__pfb__clock__sync__fff.html#a74db507b4f2fc12fa22f941882b7d300">00212</a> <span class="keywordtype">void</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#a74db507b4f2fc12fa22f941882b7d300">set_max_rate_deviation</a>(<span class="keywordtype">float</span> m)
<a name="l00213"></a>00213 {
<a name="l00214"></a>00214 d_max_dev = m;
<a name="l00215"></a>00215 }
<a name="l00216"></a>00216
<a name="l00217"></a>00217 <span class="keywordtype">bool</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#a492a431a8541bdbb503aae72e4b11893" title="Confirm that ninputs and noutputs is an acceptable combination.">check_topology</a>(<span class="keywordtype">int</span> ninputs, <span class="keywordtype">int</span> noutputs);
<a name="l00218"></a>00218
<a name="l00219"></a>00219 <span class="keywordtype">int</span> <a class="code" href="classgr__pfb__clock__sync__fff.html#aca7162716f0ae7070c30a8af110c34d5" title="compute output items from input items">general_work</a> (<span class="keywordtype">int</span> noutput_items,
<a name="l00220"></a>00220 <a class="code" href="classstd_1_1vector.html">gr_vector_int</a> &ninput_items,
<a name="l00221"></a>00221 <a class="code" href="classstd_1_1vector.html">gr_vector_const_void_star</a> &input_items,
<a name="l00222"></a>00222 <a class="code" href="classstd_1_1vector.html">gr_vector_void_star</a> &output_items);
<a name="l00223"></a>00223 };
<a name="l00224"></a>00224
<a name="l00225"></a>00225 <span class="preprocessor">#endif</span>
</pre></div></div>
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