Commit ec91065abc62cf760eae8829a63d8bf8af8f48e2

Authored by Arthur HUGEAT
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Ajout du tableau comparatif entre Fir compiler et Oscimp

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ifcs2018_journal.tex
... ... @@ -120,7 +120,7 @@
120 120 signals, High Level Synthesis (HLS) languages \cite{kasbah2008multigrid} are not considered but
121 121 the problem is tackled at the Very-high-speed-integrated-circuit Hardware Description Language
122 122 (VHDL) level.
123   -{\color{red}Since latency is not an issue in a openloop phase noise characterization instrument,
  123 +{\color{red}Since latency is not an issue in a openloop phase noise characterization instrument,
124 124 the large
125 125 numbre of taps in the FIR, as opposed to the shorter Infinite Impulse Response (IIR) filter,
126 126 is not considered as an issue as would be in a closed loop system.} % r2.4
... ... @@ -144,7 +144,7 @@
144 144 relation between number of fiter taps and quantization, Fig. \ref{float_vs_int} exhibits
145 145 a 128-coefficient FIR bandpass filter designed using floating point numbers (blue). Upon
146 146 quantization on 6~bit integers, 60 of the 128~coefficients in the beginning and end of the
147   -taps become null, {\color{red}making the large number of coefficients irrelevant: processing
  147 +taps become null, {\color{red}making the large number of coefficients irrelevant: processing
148 148 resources % r1.1
149 149 are hence saved by shrinking the filter length.} This tradeoff aimed at minimizing resources
150 150 to reach a given rejection level, or maximizing out of band rejection for a given computational
151 151  
... ... @@ -197,10 +197,10 @@
197 197  
198 198 {\color{red}
199 199 The first step of our approach is to model the DSP chain. Since we aim at only optimizing % r1.3
200   -the filtering part of the signal processing chain, we have not included the PRN generator or the
201   -ADC in the model: the input data size and rate are considered fixed and defined by the hardware.
  200 +the filtering part of the signal processing chain, we have not included the PRN generator or the
  201 +ADC in the model: the input data size and rate are considered fixed and defined by the hardware.
202 202 The filtering can be done in two ways, either by considering a single monolithic FIR filter
203   -requiring many coefficients to reach the targeted noise rejection ratio, or by
  203 +requiring many coefficients to reach the targeted noise rejection ratio, or by
204 204 cascading multiple FIR filters, each with fewer coefficients than found in the monolithic filter.}
205 205  
206 206 After each filter we leave the possibility of shifting the filtered data to consume
... ... @@ -298,7 +298,7 @@
298 298 Our criterion to compute the filter rejection considers
299 299 % r2.8 et r2.2 r2.3
300 300 the maximum magnitude within the stopband, to which the {\color{red}sum of the absolute values
301   -within the passband is subtracted to avoid filters with excessive ripples}. With this
  301 +within the passband is subtracted to avoid filters with excessive ripples}. With this
302 302 criterion, we meet the expected rejection capability of low pass filters as shown in figure~\ref{fig:custom_criterion}.
303 303  
304 304 % \begin{figure}
... ... @@ -1010,6 +1010,25 @@
1010 1010 needed in the previous section. Indeed the worst time in this case is only 17~minutes,
1011 1011 compared to 3~days in the previous section: this problem is more easily solved than the
1012 1012 previous one.
  1013 +
  1014 +\renewcommand{\arraystretch}{1.2}
  1015 +\begin{table}
  1016 +\centering
  1017 +\caption{Resource consumption compared between the FIR Compiler from Xilinx and our FIR block}
  1018 +\label{tbl:area_time_comp}
  1019 +\begin{tabular}{|c|c|c|c|c|c|c|}
  1020 +\hline
  1021 +\multirow{2}{*}{} & \multicolumn{3}{c|}{Xilinx} & \multicolumn{3}{c|}{Our FIR block} \\ \cline{2-7}
  1022 + & LUT & BRAM & DSP & LUT & BRAM & DSP \\ \hline
  1023 +MAX/500 & 177 & 0 & 21 & 249 & 1 & 21 \\ \hline
  1024 +MAX/1000 & 306 & 0 & 37 & 453 & 1 & 37 \\ \hline
  1025 +MAX/1500 & 418 & 0 & 47 & 627 & 1 & 47 \\ \hline
  1026 +MIN/40 & 225 & 0 & 27 & 347 & 1 & 27 \\ \hline
  1027 +MIN/60 & 322 & 0 & 39 & 334 & 1 & 39 \\ \hline
  1028 +MIN/80 & 482 & 0 & 55 & 772 & 1 & 55 \\ \hline
  1029 +\end{tabular}
  1030 +\end{table}
  1031 +\renewcommand{\arraystretch}{1}
1013 1032  
1014 1033 \section{Conclusion}
1015 1034