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[/] [mkjpeg/] [trunk/] [design/] [quantizer/] [ROMR.vhd] - Blame information for rev 31

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Line No. Rev Author Line
1 25 mikel262 
--------------------------------------------------------------------------------
2 
--                                                                            --
3 
--                          V H D L    F I L E                                --
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--                          COPYRIGHT (C) 2009                                --
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--                                                                            --
6 
--------------------------------------------------------------------------------
7 
--
8 
-- Title       : ROMR
9 
-- Design      : EV_JPEG_ENC
10 
-- Author      : Michal Krepa
11 
--
12 
--------------------------------------------------------------------------------
13 
--
14 
-- File        : ROMR.VHD
15 
-- Created     : Wed Mar 19 21:09 2009
16 
--
17 
--------------------------------------------------------------------------------
18 
--
19 
--  Description : Reciprocal of 1/X where X is 1..255
20 
--
21 
--------------------------------------------------------------------------------
22 
 
23 
library IEEE;
24 
  use IEEE.STD_LOGIC_1164.all;
25 
  use ieee.numeric_std.all;
26 
 
27 
entity ROMR is
28 
  generic
29 
    (
30 
      ROMADDR_W     : INTEGER := 8;
31 
      ROMDATA_W     : INTEGER := 16
32 
    );
33 
  port(
34 
       addr         : in  STD_LOGIC_VECTOR(ROMADDR_W-1 downto 0);
35 
       clk          : in  STD_LOGIC;
36 
 
37 
       datao        : out STD_LOGIC_VECTOR(ROMDATA_W-1 downto 0)
38 
  );
39 
 
40 
end ROMR;
41 
 
42 
architecture RTL of ROMR is
43 
 
44 
  constant CK : integer := 256*256;
45 
  type ROMQ_TYPE is array (0 to 2**ROMADDR_W-1)
46 
            of INTEGER range 0 to 2**ROMDATA_W-1;
47 
 
48 
  constant rom : ROMQ_TYPE :=
49 
  (
50 
           0,
51 
       65535,
52 
       32768,
53 
       21845,
54 
       16384,
55 
       13107,
56 
       10923,
57 
        9362,
58 
        8192,
59 
        7282,
60 
        6554,
61 
        5958,
62 
        5461,
63 
        5041,
64 
        4681,
65 
        4369,
66 
        4096,
67 
        3855,
68 
        3641,
69 
        3449,
70 
        3277,
71 
        3121,
72 
        2979,
73 
        2849,
74 
        2731,
75 
        2621,
76 
        2521,
77 
        2427,
78 
        2341,
79 
        2260,
80 
        2185,
81 
        2114,
82 
        2048,
83 
        1986,
84 
        1928,
85 
        1872,
86 
        1820,
87 
        1771,
88 
        1725,
89 
        1680,
90 
        1638,
91 
        1598,
92 
        1560,
93 
        1524,
94 
        1489,
95 
        1456,
96 
        1425,
97 
        1394,
98 
        1365,
99 
        1337,
100 
        1311,
101 
        1285,
102 
        1260,
103 
        1237,
104 
        1214,
105 
        1192,
106 
        1170,
107 
        1150,
108 
        1130,
109 
        1111,
110 
        1092,
111 
        1074,
112 
        1057,
113 
        1040,
114 
        1024,
115 
        1008,
116 
         993,
117 
         978,
118 
         964,
119 
         950,
120 
         936,
121 
         923,
122 
         910,
123 
         898,
124 
         886,
125 
         874,
126 
         862,
127 
         851,
128 
         840,
129 
         830,
130 
         819,
131 
         809,
132 
         799,
133 
         790,
134 
         780,
135 
         771,
136 
         762,
137 
         753,
138 
         745,
139 
         736,
140 
         728,
141 
         720,
142 
         712,
143 
         705,
144 
         697,
145 
         690,
146 
         683,
147 
         676,
148 
         669,
149 
         662,
150 
         655,
151 
         649,
152 
         643,
153 
         636,
154 
         630,
155 
         624,
156 
         618,
157 
         612,
158 
         607,
159 
         601,
160 
         596,
161 
         590,
162 
         585,
163 
         580,
164 
         575,
165 
         570,
166 
         565,
167 
         560,
168 
         555,
169 
         551,
170 
         546,
171 
         542,
172 
         537,
173 
         533,
174 
         529,
175 
         524,
176 
         520,
177 
         516,
178 
         512,
179 
         508,
180 
         504,
181 
         500,
182 
         496,
183 
         493,
184 
         489,
185 
         485,
186 
         482,
187 
         478,
188 
         475,
189 
         471,
190 
         468,
191 
         465,
192 
         462,
193 
         458,
194 
         455,
195 
         452,
196 
         449,
197 
         446,
198 
         443,
199 
         440,
200 
         437,
201 
         434,
202 
         431,
203 
         428,
204 
         426,
205 
         423,
206 
         420,
207 
         417,
208 
         415,
209 
         412,
210 
         410,
211 
         407,
212 
         405,
213 
         402,
214 
         400,
215 
         397,
216 
         395,
217 
         392,
218 
         390,
219 
         388,
220 
         386,
221 
         383,
222 
         381,
223 
         379,
224 
         377,
225 
         374,
226 
         372,
227 
         370,
228 
         368,
229 
         366,
230 
         364,
231 
         362,
232 
         360,
233 
         358,
234 
         356,
235 
         354,
236 
         352,
237 
         350,
238 
         349,
239 
         347,
240 
         345,
241 
         343,
242 
         341,
243 
         340,
244 
         338,
245 
         336,
246 
         334,
247 
         333,
248 
         331,
249 
         329,
250 
         328,
251 
         326,
252 
         324,
253 
         323,
254 
         321,
255 
         320,
256 
         318,
257 
         317,
258 
         315,
259 
         314,
260 
         312,
261 
         311,
262 
         309,
263 
         308,
264 
         306,
265 
         305,
266 
         303,
267 
         302,
268 
         301,
269 
         299,
270 
         298,
271 
         297,
272 
         295,
273 
         294,
274 
         293,
275 
         291,
276 
         290,
277 
         289,
278 
         287,
279 
         286,
280 
         285,
281 
         284,
282 
         282,
283 
         281,
284 
         280,
285 
         279,
286 
         278,
287 
         277,
288 
         275,
289 
         274,
290 
         273,
291 
         272,
292 
         271,
293 
         270,
294 
         269,
295 
         267,
296 
         266,
297 
         265,
298 
         264,
299 
         263,
300 
         262,
301 
         261,
302 
         260,
303 
         259,
304 
         258,
305 
         257
306 
  );
307 
 
308 
 
309 
 
310 
  signal addr_reg : STD_LOGIC_VECTOR(ROMADDR_W-1 downto 0);
311 
begin
312 
 
313 
  datao <= STD_LOGIC_VECTOR(TO_UNSIGNED( rom( TO_INTEGER(UNSIGNED(addr_reg)) ), ROMDATA_W));
314 
 
315 
  process(clk)
316 
  begin
317 
   if clk = '1' and clk'event then
318 
     addr_reg <= addr;
319 
   end if;
320 
  end process;
321 
 
322 
end RTL;

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