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[/] [all_digital_fm_receiver/] [trunk/] [nco.vhd] - Blame information for rev 5

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Line No. Rev Author Line
1 2 rahmatulla 
LIBRARY ieee;
2 
USE ieee.std_logic_1164.all;
3 
USE IEEE.numeric_std.ALL;
4 
 
5 
 
6 
 
7 
ENTITY nco IS
8 
-- Declarations
9 
 port ( clk   : in  std_logic;
10 
                        reset   : in  std_logic;
11 
                        din                     : in    signed(11 downto 0);
12 
                        dout    : out signed(7 downto 0)
13 
                );
14 
END nco ;
15 
 
16 
-- hds interface_end
17 
ARCHITECTURE behavior OF nco IS
18 
type vectype is array (0 to 256) of signed(7 downto 0);
19 
-- ROM cosrom
20 
constant cosrom  : vectype := (
21 
 
22 
1 => "01111111",
23 
2 => "01111111",
24 
3 => "01111111",
25 
4 => "01111111",
26 
5 => "01111111",
27 
6 => "01111111",
28 
7 => "01111111",
29 
8 => "01111111",
30 
9 => "01111111",
31 
10 => "01111111",
32 
11 => "01111111",
33 
12 => "01111111",
34 
13 => "01111111",
35 
14 => "01111111",
36 
15 => "01111111",
37 
16 => "01111111",
38 
17 => "01111111",
39 
18 => "01111111",
40 
19 => "01111111",
41 
20 => "01111111",
42 
21 => "01111111",
43 
22 => "01111111",
44 
23 => "01111111",
45 
24 => "01111111",
46 
25 => "01111110",
47 
26 => "01111110",
48 
27 => "01111110",
49 
28 => "01111110",
50 
29 => "01111110",
51 
30 => "01111110",
52 
31 => "01111110",
53 
32 => "01111110",
54 
33 => "01111101",
55 
34 => "01111101",
56 
35 => "01111101",
57 
36 => "01111101",
58 
37 => "01111101",
59 
38 => "01111101",
60 
39 => "01111100",
61 
40 => "01111100",
62 
41 => "01111100",
63 
42 => "01111100",
64 
43 => "01111100",
65 
44 => "01111011",
66 
45 => "01111011",
67 
46 => "01111011",
68 
47 => "01111011",
69 
48 => "01111010",
70 
49 => "01111010",
71 
50 => "01111010",
72 
51 => "01111010",
73 
52 => "01111010",
74 
53 => "01111001",
75 
54 => "01111001",
76 
55 => "01111001",
77 
56 => "01111001",
78 
57 => "01111000",
79 
58 => "01111000",
80 
59 => "01111000",
81 
60 => "01110111",
82 
61 => "01110111",
83 
62 => "01110111",
84 
63 => "01110111",
85 
64 => "01110110",
86 
65 => "01110110",
87 
66 => "01110110",
88 
67 => "01110101",
89 
68 => "01110101",
90 
69 => "01110101",
91 
70 => "01110100",
92 
71 => "01110100",
93 
72 => "01110100",
94 
73 => "01110011",
95 
74 => "01110011",
96 
75 => "01110011",
97 
76 => "01110010",
98 
77 => "01110010",
99 
78 => "01110010",
100 
79 => "01110001",
101 
80 => "01110001",
102 
81 => "01110001",
103 
82 => "01110000",
104 
83 => "01110000",
105 
84 => "01101111",
106 
85 => "01101111",
107 
86 => "01101111",
108 
87 => "01101110",
109 
88 => "01101110",
110 
89 => "01101101",
111 
90 => "01101101",
112 
91 => "01101101",
113 
92 => "01101100",
114 
93 => "01101100",
115 
94 => "01101011",
116 
95 => "01101011",
117 
96 => "01101010",
118 
97 => "01101010",
119 
98 => "01101010",
120 
99 => "01101001",
121 
100 => "01101001",
122 
101 => "01101000",
123 
102 => "01101000",
124 
103 => "01100111",
125 
104 => "01100111",
126 
105 => "01100110",
127 
106 => "01100110",
128 
107 => "01100101",
129 
108 => "01100101",
130 
109 => "01100100",
131 
110 => "01100100",
132 
111 => "01100011",
133 
112 => "01100011",
134 
113 => "01100010",
135 
114 => "01100010",
136 
115 => "01100001",
137 
116 => "01100001",
138 
117 => "01100000",
139 
118 => "01100000",
140 
119 => "01011111",
141 
120 => "01011111",
142 
121 => "01011110",
143 
122 => "01011110",
144 
123 => "01011101",
145 
124 => "01011101",
146 
125 => "01011100",
147 
126 => "01011100",
148 
127 => "01011011",
149 
128 => "01011011",
150 
129 => "01011010",
151 
130 => "01011001",
152 
131 => "01011001",
153 
132 => "01011000",
154 
133 => "01011000",
155 
134 => "01010111",
156 
135 => "01010111",
157 
136 => "01010110",
158 
137 => "01010101",
159 
138 => "01010101",
160 
139 => "01010100",
161 
140 => "01010100",
162 
141 => "01010011",
163 
142 => "01010010",
164 
143 => "01010010",
165 
144 => "01010001",
166 
145 => "01010001",
167 
146 => "01010000",
168 
147 => "01001111",
169 
148 => "01001111",
170 
149 => "01001110",
171 
150 => "01001110",
172 
151 => "01001101",
173 
152 => "01001100",
174 
153 => "01001100",
175 
154 => "01001011",
176 
155 => "01001010",
177 
156 => "01001010",
178 
157 => "01001001",
179 
158 => "01001000",
180 
159 => "01001000",
181 
160 => "01000111",
182 
161 => "01000111",
183 
162 => "01000110",
184 
163 => "01000101",
185 
164 => "01000101",
186 
165 => "01000100",
187 
166 => "01000011",
188 
167 => "01000011",
189 
168 => "01000010",
190 
169 => "01000001",
191 
170 => "01000001",
192 
171 => "01000000",
193 
172 => "00111111",
194 
173 => "00111110",
195 
174 => "00111110",
196 
175 => "00111101",
197 
176 => "00111100",
198 
177 => "00111100",
199 
178 => "00111011",
200 
179 => "00111010",
201 
180 => "00111010",
202 
181 => "00111001",
203 
182 => "00111000",
204 
183 => "00111000",
205 
184 => "00110111",
206 
185 => "00110110",
207 
186 => "00110101",
208 
187 => "00110101",
209 
188 => "00110100",
210 
189 => "00110011",
211 
190 => "00110011",
212 
191 => "00110010",
213 
192 => "00110001",
214 
193 => "00110000",
215 
194 => "00110000",
216 
195 => "00101111",
217 
196 => "00101110",
218 
197 => "00101101",
219 
198 => "00101101",
220 
199 => "00101100",
221 
200 => "00101011",
222 
201 => "00101010",
223 
202 => "00101010",
224 
203 => "00101001",
225 
204 => "00101000",
226 
205 => "00100111",
227 
206 => "00100111",
228 
207 => "00100110",
229 
208 => "00100101",
230 
209 => "00100100",
231 
210 => "00100100",
232 
211 => "00100011",
233 
212 => "00100010",
234 
213 => "00100001",
235 
214 => "00100001",
236 
215 => "00100000",
237 
216 => "00011111",
238 
217 => "00011110",
239 
218 => "00011110",
240 
219 => "00011101",
241 
220 => "00011100",
242 
221 => "00011011",
243 
222 => "00011011",
244 
223 => "00011010",
245 
224 => "00011001",
246 
225 => "00011000",
247 
226 => "00011000",
248 
227 => "00010111",
249 
228 => "00010110",
250 
229 => "00010101",
251 
230 => "00010100",
252 
231 => "00010100",
253 
232 => "00010011",
254 
233 => "00010010",
255 
234 => "00010001",
256 
235 => "00010001",
257 
236 => "00010000",
258 
237 => "00001111",
259 
238 => "00001110",
260 
239 => "00001101",
261 
240 => "00001101",
262 
241 => "00001100",
263 
242 => "00001011",
264 
243 => "00001010",
265 
244 => "00001010",
266 
245 => "00001001",
267 
246 => "00001000",
268 
247 => "00000111",
269 
248 => "00000110",
270 
249 => "00000110",
271 
250 => "00000101",
272 
251 => "00000100",
273 
252 => "00000011",
274 
253 => "00000010",
275 
254 => "00000010",
276 
255 => "00000001",
277 
256 => "00000000");
278 
 
279 
signal dtemp  : unsigned(17 downto 0);
280 
signal din_buf  : signed(17 downto 0);
281 
signal dtemp1  : integer;
282 
constant offset : unsigned(17 downto 0) := "000100000000000000";
283 
 
284 
begin
285 
 
286 
process(CLK, RESET)
287 
begin
288 
        if (RESET='1') then
289 
            dout <= (others => '0');
290 
            din_buf <= (others => '0');
291 
                                                dtemp <= (others => '0');
292 
                                                dtemp1 <= 0;
293 
        elsif rising_edge(CLK) then
294 
                        din_buf <= din(11)&din(11)&din(11)&din(11)&din(11)&din(11)&din;
295 
                                                dtemp <= dtemp + unsigned(din_buf) + offset;
296 
                                                dtemp1 <= to_integer(dtemp(17 downto 8));
297 
                                                if (dtemp1 >= 0) and (dtemp1 < 257) then
298 
                                                        dout <= cosrom(dtemp1);
299 
                                                elsif (dtemp1 >= 257) and (dtemp1 < 513) then
300 
                                                        dout <= -cosrom(512-dtemp1);
301 
                                                elsif (dtemp1 >= 513) and (dtemp1 < 769) then
302 
                                                        dout <= -cosrom(dtemp1-512);
303 
                                                else
304 
                                                        dout <= cosrom(1024-dtemp1);
305 
                                                end if;
306 
    end if;
307 
end process;
308 
END behavior;

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