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// Copyright (C) 2012
// Ashwin A. Mendon
//
// This file is part of SATA2 core.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
 
////////////////////////////////////////////////////////////////////////////////////////
// ENTITY: scrambler
// Version: 1.0
// Author:  Ashwin Mendon
// Description: This sub/module implements the Scrambler Circuit for the SATA Protocol
//              The code provides a parallel implementation of the following
//              generator polynomial
//                          16  15  13  4
//                  G(x) = x + x + x + x + 1
//              The output of this scrambler is then XORed with the input data DWORD
//              The scrambler is initialized to a value of 0xF0F6.
//              The first DWORD output of the implementation is equal to 0xC2D2768D
// PORTS:
/////////////////////////////////////////////////////////////////////////////////////////
 
 
module scrambler (
  clk,
  rst,
  en,
  prim_scrambler,
  din,
  dout
);
input               clk;
input               rst;
input               en;
input               prim_scrambler;
input   [31:0]      din;
output  [31:0]      dout;
 
//Parameters
parameter           SCRAMBLER_INIT  = 16'hF0F6;
 
//Registers/Wires
reg     [15:0]      context;
wire    [31:0]      context_next;
reg     [31:0]      context_reg;
 
//Synchronous Logic
always @ (posedge clk) begin
  if (rst) begin
    context         <=  SCRAMBLER_INIT;
    context_reg     <=  32'h0;
  end
  else begin
    if (en) begin
      context         <=  context_next[31:16];
      context_reg     <=  context_next;
    end
  end
end
 
assign  dout           =  (prim_scrambler) ? context_reg : context_reg ^ din;
 
//Aysnchronous Logic
assign context_next[31] =  context[12] ^
                           context[10] ^
                           context[7]  ^
                           context[3]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[30] =  context[15] ^
                           context[14] ^
                           context[12] ^
                           context[11] ^
                           context[9]  ^
                           context[6]  ^
                           context[3]  ^
                           context[2]  ^
                           context[0];
 
assign context_next[29] =  context[15] ^
                           context[13] ^
                           context[12] ^
                           context[11] ^
                           context[10] ^
                           context[8]  ^
                           context[5]  ^
                           context[3]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[28] =  context[14] ^
                           context[12] ^
                           context[11] ^
                           context[10] ^
                           context[9]  ^
                           context[7]  ^
                           context[4]  ^
                           context[2]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[27] =  context[15] ^
                           context[14] ^
                           context[13] ^
                           context[12] ^
                           context[11] ^
                           context[10] ^
                           context[9]  ^
                           context[8]  ^
                           context[6]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[26] =  context[15] ^
                           context[13] ^
                           context[11] ^
                           context[10] ^
                           context[9]  ^
                           context[8]  ^
                           context[7]  ^
                           context[5]  ^
                           context[3]  ^
                           context[0];
 
assign context_next[25] =  context[15] ^
                           context[10] ^
                           context[9]  ^
                           context[8]  ^
                           context[7]  ^
                           context[6]  ^
                           context[4]  ^
                           context[3]  ^
                           context[2];
 
assign context_next[24] =  context[14] ^
                           context[9]  ^
                           context[8]  ^
                           context[7]  ^
                           context[6]  ^
                           context[5]  ^
                           context[3]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[23] =  context[13] ^
                           context[8]  ^
                           context[7]  ^
                           context[6]  ^
                           context[5]  ^
                           context[4]  ^
                           context[2]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[22] =  context[15] ^
                           context[14] ^
                           context[7]  ^
                           context[6]  ^
                           context[5]  ^
                           context[4]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[21] =  context[15] ^
                           context[13] ^
                           context[12] ^
                           context[6]  ^
                           context[5]  ^
                           context[4]  ^
                           context[0];
 
assign context_next[20] =  context[15] ^
                           context[11] ^
                           context[5]  ^
                           context[4];
 
assign context_next[19] =  context[14] ^
                           context[10] ^
                           context[4]  ^
                           context[3];
 
assign context_next[18] =  context[13] ^
                           context[9]  ^
                           context[3]  ^
                           context[2];
 
assign context_next[17] =  context[12] ^
                           context[8]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[16] =  context[11] ^
                           context[7]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[15] =  context[15] ^
                           context[14] ^
                           context[12] ^
                           context[10] ^
                           context[6]  ^
                           context[3]  ^
                           context[0];
 
assign context_next[14] =  context[15] ^
                           context[13] ^
                           context[12] ^
                           context[11] ^
                           context[9]  ^
                           context[5]  ^
                           context[3]  ^
                           context[2];
 
assign context_next[13] =  context[14] ^
                           context[12] ^
                           context[11] ^
                           context[10] ^
                           context[8]  ^
                           context[4]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[12] =  context[13] ^
                           context[11] ^
                           context[10] ^
                           context[9]  ^
                           context[7]  ^
                           context[3]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[11] =  context[15] ^
                           context[14] ^
                           context[10] ^
                           context[9] ^
                           context[8] ^
                           context[6] ^
                           context[3] ^
                           context[2] ^
                           context[0];
 
assign context_next[10] =  context[15] ^
                           context[13] ^
                           context[12] ^
                           context[9]  ^
                           context[8]  ^
                           context[7]  ^
                           context[5]  ^
                           context[3]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[9] =   context[14] ^
                           context[12] ^
                           context[11] ^
                           context[8]  ^
                           context[7]  ^
                           context[6]  ^
                           context[4]  ^
                           context[2]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[8] =   context[15] ^
                           context[14] ^
                           context[13] ^
                           context[12] ^
                           context[11] ^
                           context[10] ^
                           context[7]  ^
                           context[6]  ^
                           context[5]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[7] =   context[15] ^
                           context[13] ^
                           context[11] ^
                           context[10] ^
                           context[9]  ^
                           context[6]  ^
                           context[5]  ^
                           context[4]  ^
                           context[3]  ^
                           context[0];
 
assign context_next[6] =   context[15] ^
                           context[10] ^
                           context[9]  ^
                           context[8]  ^
                           context[5]  ^
                           context[4]  ^
                           context[2];
 
assign context_next[5] =   context[14] ^
                           context[9]  ^
                           context[8]  ^
                           context[7]  ^
                           context[4]  ^
                           context[3]  ^
                           context[1];
 
assign context_next[4] =   context[13] ^
                           context[8]  ^
                           context[7]  ^
                           context[6]  ^
                           context[3]  ^
                           context[2]  ^
                           context[0];
 
assign context_next[3] =   context[15] ^
                           context[14] ^
                           context[7]  ^
                           context[6]  ^
                           context[5]  ^
                           context[3]  ^
                           context[2]  ^
                           context[1];
 
assign context_next[2] =   context[14] ^
                           context[13] ^
                           context[6]  ^
                           context[5]  ^
                           context[4]  ^
                           context[2]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[1] =   context[15] ^
                           context[14] ^
                           context[13] ^
                           context[5]  ^
                           context[4]  ^
                           context[1]  ^
                           context[0];
 
assign context_next[0] =   context[15] ^
                           context[13] ^
                           context[4]  ^
                           context[0];
 
 
 
 
endmodule

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[/] [nysa_sata/] [trunk/] [rtl/] [link/] [scrambler.v] - Blame information for rev 2

Line No.	Rev	Author	Line
1	2	cospan	`// Copyright (C) 2012`
2			`// Ashwin A. Mendon`
3			`//`
4			`// This file is part of SATA2 core.`
5			`//`
6			`// This program is free software; you can redistribute it and/or modify`
7			`// it under the terms of the GNU General Public License as published by`
8			`// the Free Software Foundation; either version 3 of the License, or`
9			`// (at your option) any later version.`
10			`//`
11			`// This program is distributed in the hope that it will be useful,`
12			`// but WITHOUT ANY WARRANTY; without even the implied warranty of`
13			`// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the`
14			`// GNU General Public License for more details.`
15			`//`
16			`// You should have received a copy of the GNU General Public License`
17			`// along with this program. If not, see <http://www.gnu.org/licenses/>.`
18
19
20
21			`////////////////////////////////////////////////////////////////////////////////////////`
22			`// ENTITY: scrambler`
23			`// Version: 1.0`
24			`// Author: Ashwin Mendon`
25			`// Description: This sub/module implements the Scrambler Circuit for the SATA Protocol`
26			`// The code provides a parallel implementation of the following`
27			`// generator polynomial`
28			`// 16 15 13 4`
29			`// G(x) = x + x + x + x + 1`
30			`// The output of this scrambler is then XORed with the input data DWORD`
31			`// The scrambler is initialized to a value of 0xF0F6.`
32			`// The first DWORD output of the implementation is equal to 0xC2D2768D`
33			`// PORTS:`
34			`/////////////////////////////////////////////////////////////////////////////////////////`
35
36
37			`module scrambler (`
38			`clk,`
39			`rst,`
40			`en,`
41			`prim_scrambler,`
42			`din,`
43			`dout`
44			`);`
45			`input clk;`
46			`input rst;`
47			`input en;`
48			`input prim_scrambler;`
49			`input [31:0] din;`
50			`output [31:0] dout;`
51
52			`//Parameters`
53			`parameter SCRAMBLER_INIT = 16'hF0F6;`
54
55			`//Registers/Wires`
56			`reg [15:0] context;`
57			`wire [31:0] context_next;`
58			`reg [31:0] context_reg;`
59
60			`//Synchronous Logic`
61			`always @ (posedge clk) begin`
62			`if (rst) begin`
63			`context <= SCRAMBLER_INIT;`
64			`context_reg <= 32'h0;`
65			`end`
66			`else begin`
67			`if (en) begin`
68			`context <= context_next[31:16];`
69			`context_reg <= context_next;`
70			`end`
71			`end`
72			`end`
73
74			`assign dout = (prim_scrambler) ? context_reg : context_reg ^ din;`
75
76			`//Aysnchronous Logic`
77			`assign context_next[31] = context[12] ^`
78			`context[10] ^`
79			`context[7] ^`
80			`context[3] ^`
81			`context[1] ^`
82			`context[0];`
83
84			`assign context_next[30] = context[15] ^`
85			`context[14] ^`
86			`context[12] ^`
87			`context[11] ^`
88			`context[9] ^`
89			`context[6] ^`
90			`context[3] ^`
91			`context[2] ^`
92			`context[0];`
93
94			`assign context_next[29] = context[15] ^`
95			`context[13] ^`
96			`context[12] ^`
97			`context[11] ^`
98			`context[10] ^`
99			`context[8] ^`
100			`context[5] ^`
101			`context[3] ^`
102			`context[2] ^`
103			`context[1];`
104
105			`assign context_next[28] = context[14] ^`
106			`context[12] ^`
107			`context[11] ^`
108			`context[10] ^`
109			`context[9] ^`
110			`context[7] ^`
111			`context[4] ^`
112			`context[2] ^`
113			`context[1] ^`
114			`context[0];`
115
116			`assign context_next[27] = context[15] ^`
117			`context[14] ^`
118			`context[13] ^`
119			`context[12] ^`
120			`context[11] ^`
121			`context[10] ^`
122			`context[9] ^`
123			`context[8] ^`
124			`context[6] ^`
125			`context[1] ^`
126			`context[0];`
127
128			`assign context_next[26] = context[15] ^`
129			`context[13] ^`
130			`context[11] ^`
131			`context[10] ^`
132			`context[9] ^`
133			`context[8] ^`
134			`context[7] ^`
135			`context[5] ^`
136			`context[3] ^`
137			`context[0];`
138
139			`assign context_next[25] = context[15] ^`
140			`context[10] ^`
141			`context[9] ^`
142			`context[8] ^`
143			`context[7] ^`
144			`context[6] ^`
145			`context[4] ^`
146			`context[3] ^`
147			`context[2];`
148
149			`assign context_next[24] = context[14] ^`
150			`context[9] ^`
151			`context[8] ^`
152			`context[7] ^`
153			`context[6] ^`
154			`context[5] ^`
155			`context[3] ^`
156			`context[2] ^`
157			`context[1];`
158
159			`assign context_next[23] = context[13] ^`
160			`context[8] ^`
161			`context[7] ^`
162			`context[6] ^`
163			`context[5] ^`
164			`context[4] ^`
165			`context[2] ^`
166			`context[1] ^`
167			`context[0];`
168
169			`assign context_next[22] = context[15] ^`
170			`context[14] ^`
171			`context[7] ^`
172			`context[6] ^`
173			`context[5] ^`
174			`context[4] ^`
175			`context[1] ^`
176			`context[0];`
177
178			`assign context_next[21] = context[15] ^`
179			`context[13] ^`
180			`context[12] ^`
181			`context[6] ^`
182			`context[5] ^`
183			`context[4] ^`
184			`context[0];`
185
186			`assign context_next[20] = context[15] ^`
187			`context[11] ^`
188			`context[5] ^`
189			`context[4];`
190
191			`assign context_next[19] = context[14] ^`
192			`context[10] ^`
193			`context[4] ^`
194			`context[3];`
195
196			`assign context_next[18] = context[13] ^`
197			`context[9] ^`
198			`context[3] ^`
199			`context[2];`
200
201			`assign context_next[17] = context[12] ^`
202			`context[8] ^`
203			`context[2] ^`
204			`context[1];`
205
206			`assign context_next[16] = context[11] ^`
207			`context[7] ^`
208			`context[1] ^`
209			`context[0];`
210
211			`assign context_next[15] = context[15] ^`
212			`context[14] ^`
213			`context[12] ^`
214			`context[10] ^`
215			`context[6] ^`
216			`context[3] ^`
217			`context[0];`
218
219			`assign context_next[14] = context[15] ^`
220			`context[13] ^`
221			`context[12] ^`
222			`context[11] ^`
223			`context[9] ^`
224			`context[5] ^`
225			`context[3] ^`
226			`context[2];`
227
228			`assign context_next[13] = context[14] ^`
229			`context[12] ^`
230			`context[11] ^`
231			`context[10] ^`
232			`context[8] ^`
233			`context[4] ^`
234			`context[2] ^`
235			`context[1];`
236
237			`assign context_next[12] = context[13] ^`
238			`context[11] ^`
239			`context[10] ^`
240			`context[9] ^`
241			`context[7] ^`
242			`context[3] ^`
243			`context[1] ^`
244			`context[0];`
245
246			`assign context_next[11] = context[15] ^`
247			`context[14] ^`
248			`context[10] ^`
249			`context[9] ^`
250			`context[8] ^`
251			`context[6] ^`
252			`context[3] ^`
253			`context[2] ^`
254			`context[0];`
255
256			`assign context_next[10] = context[15] ^`
257			`context[13] ^`
258			`context[12] ^`
259			`context[9] ^`
260			`context[8] ^`
261			`context[7] ^`
262			`context[5] ^`
263			`context[3] ^`
264			`context[2] ^`
265			`context[1];`
266
267			`assign context_next[9] = context[14] ^`
268			`context[12] ^`
269			`context[11] ^`
270			`context[8] ^`
271			`context[7] ^`
272			`context[6] ^`
273			`context[4] ^`
274			`context[2] ^`
275			`context[1] ^`
276			`context[0];`
277
278			`assign context_next[8] = context[15] ^`
279			`context[14] ^`
280			`context[13] ^`
281			`context[12] ^`
282			`context[11] ^`
283			`context[10] ^`
284			`context[7] ^`
285			`context[6] ^`
286			`context[5] ^`
287			`context[1] ^`
288			`context[0];`
289
290			`assign context_next[7] = context[15] ^`
291			`context[13] ^`
292			`context[11] ^`
293			`context[10] ^`
294			`context[9] ^`
295			`context[6] ^`
296			`context[5] ^`
297			`context[4] ^`
298			`context[3] ^`
299			`context[0];`
300
301			`assign context_next[6] = context[15] ^`
302			`context[10] ^`
303			`context[9] ^`
304			`context[8] ^`
305			`context[5] ^`
306			`context[4] ^`
307			`context[2];`
308
309			`assign context_next[5] = context[14] ^`
310			`context[9] ^`
311			`context[8] ^`
312			`context[7] ^`
313			`context[4] ^`
314			`context[3] ^`
315			`context[1];`
316
317			`assign context_next[4] = context[13] ^`
318			`context[8] ^`
319			`context[7] ^`
320			`context[6] ^`
321			`context[3] ^`
322			`context[2] ^`
323			`context[0];`
324
325			`assign context_next[3] = context[15] ^`
326			`context[14] ^`
327			`context[7] ^`
328			`context[6] ^`
329			`context[5] ^`
330			`context[3] ^`
331			`context[2] ^`
332			`context[1];`
333
334			`assign context_next[2] = context[14] ^`
335			`context[13] ^`
336			`context[6] ^`
337			`context[5] ^`
338			`context[4] ^`
339			`context[2] ^`
340			`context[1] ^`
341			`context[0];`
342
343			`assign context_next[1] = context[15] ^`
344			`context[14] ^`
345			`context[13] ^`
346			`context[5] ^`
347			`context[4] ^`
348			`context[1] ^`
349			`context[0];`
350
351			`assign context_next[0] = context[15] ^`
352			`context[13] ^`
353			`context[4] ^`
354			`context[0];`
355
356
357
358
359			`endmodule`