Commit 48d886be993bab8469e9e4f038410adc9e58893d
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Correction des notations.
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ifcs2018_proceeding.tex
... | ... | @@ -166,11 +166,10 @@ |
166 | 166 | resources indeed matches the definition of a classical optimization problem. |
167 | 167 | |
168 | 168 | Specifically the degrees of freedom when addressing the problem of replacing the single monolithic |
169 | -FIR with a cascade of optimized filters are the number of coefficients $N_i$ of each filter $i$, | |
170 | -the number of bits $C_i$ representing the coefficients and the number of bits $D_i$ representing | |
171 | -the data fed to the filter. Because each FIR in the chain is fed the output of the previous stage, | |
169 | +FIR with a cascade of optimized filters are the number of coefficients $N_i$ of each filter $i$ and | |
170 | +the number of bits $C_i$ representing the coefficients. Because each FIR in the chain is fed the output of the previous stage, | |
172 | 171 | the optimization of the complete processing chain within a constrained resource environment is not |
173 | -trivial. The resource occupation of a FIR filter is considered as $(D_i+C_i) \times N_i$ which is | |
172 | +trivial. The resource occupation of a FIR filter is considered as $C_i \times N_i$ which is | |
174 | 173 | the number of bits needed in a worst case condition to represent the output of the FIR. Such an |
175 | 174 | occupied area estimate assumes that the number of gates scales as the number of bits and the number |
176 | 175 | of coefficients, but does not account for the detailed implementation of the hardware. Indeed, |
... | ... | @@ -199,7 +198,7 @@ |
199 | 198 | \begin{align} |
200 | 199 | \begin{cases} |
201 | 200 | \mathcal{R}_i &= \mathcal{F}(N_i, C_i)\\ |
202 | - \mathcal{A}_i &= N_i * C_i + D_i\ | |
201 | + \mathcal{A}_i &= N_i * C_i\ | |
203 | 202 | \Delta_i &= \Delta _{i-1} + \mathcal{P}_i |
204 | 203 | \end{cases} |
205 | 204 | \label{model-FIR} |
... | ... | @@ -248,13 +247,13 @@ |
248 | 247 | \begin{align*} |
249 | 248 | \mathcal{F} = \lbrace F_1 ... F_p \rbrace & \text{ All possible filters}\\ |
250 | 249 | & \text{ $p$ is the number of different filters} \\ |
251 | -C(i) & \text{ % Constant to let the | |
252 | -number of coefficients %} \\ & \text{ | |
253 | -for filter $i$}\\ | |
254 | -\pi_C(i) & \text{ % Constant to let the | |
255 | -number of bits of %}\\ & \text{ | |
256 | -each coefficient for filter $i$}\\ | |
257 | -\mathcal{A}_{\max} & \text{ Total space available inside the FPGA} | |
250 | +% N(i) & \text{ % Constant to let the | |
251 | +% number of coefficients %} \\ & \text{ | |
252 | +% for filter $i$}\\ | |
253 | +% C(i) & \text{ % Constant to let the | |
254 | +% number of bits of %}\\ & \text{ | |
255 | +% each coefficient for filter $i$}\\ | |
256 | +\mathcal{S}_{\max} & \text{ Total space available inside the FPGA} | |
258 | 257 | \end{align*} |
259 | 258 | \paragraph{Constraints} |
260 | 259 | \begin{align} |
... | ... | @@ -284,7 +283,7 @@ |
284 | 283 | |
285 | 284 | The MILP solver provides a solution to the problem by selecting a series of small FIR with |
286 | 285 | increasing number of bits representing data and coefficients as well as an increasing number |
287 | -of coefficients, instead of a single monolithic filter. | |
286 | +of coefficients, instead of a single monolithic filter. | |
288 | 287 | |
289 | 288 | \begin{figure}[h!tb] |
290 | 289 | % \includegraphics[width=\linewidth]{images/compare-fir.pdf} |