?rev1line? |
?rev2line? |
|
//----------------------------------------------------------------------//
|
|
// The MIT License
|
|
//
|
|
// Copyright (c) 2008 Abhinav Agarwal, Alfred Man Cheuk Ng
|
|
// Contact: abhiag@gmail.com
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person
|
|
// obtaining a copy of this software and associated documentation
|
|
// files (the "Software"), to deal in the Software without
|
|
// restriction, including without limitation the rights to use,
|
|
// copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the
|
|
// Software is furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be
|
|
// included in all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
|
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
|
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
// OTHER DEALINGS IN THE SOFTWARE.
|
|
//----------------------------------------------------------------------//
|
|
|
|
//**********************************************************************
|
|
// Galois field arithmetic
|
|
//----------------------------------------------------------------------
|
|
// $Id: GFArith.bsv
|
|
//
|
|
|
|
import GFTypes::*;
|
|
import Vector::*;
|
|
|
|
`include "GFInv.bsv"
|
|
|
|
// -----------------------------------------------------------
|
|
//(* noinline *)
|
|
function Byte gf_mult(Byte left, Byte right);
|
|
|
|
Bit#(15) first = 15'b0;
|
|
Bit#(15) result = 15'b0;
|
|
|
|
// this function bring back higher degree values back to the field
|
|
function Bit#(15) getNewResult(Integer shift, Bit#(15) res);
|
|
Bit#(15) shiftPoly = zeroExtend(primitive_poly) << shift;
|
|
Bit#(15) newRes = res ^ ((res[8+shift] == 1'b1) ? shiftPoly : 0);
|
|
return newRes;
|
|
endfunction
|
|
|
|
for (Integer i = 0; i < 8; i = i + 1)
|
|
for (Integer j = 0; j < 8 ; j = j + 1)
|
|
begin
|
|
if (first[i+j] == 0) // initialize result[i+j]
|
|
result[i+j] = (left[i] & right[j]);
|
|
else // accumulate
|
|
result[i+j] = result[i+j] ^ (left[i] & right[j]);
|
|
first[i+j] = 1; // only initialize each signal once
|
|
end
|
|
|
|
Vector#(7,Integer) shftAmntV = genVector;
|
|
Bit#(15) finalResult = foldr(getNewResult,result,shftAmntV);
|
|
|
|
return finalResult[7:0];
|
|
|
|
endfunction
|
|
|
|
(* noinline *)
|
|
function Byte gf_mult_inst(Byte x, Byte y);
|
|
return gf_mult(x,y);
|
|
endfunction
|
|
|
|
// -----------------------------------------------------------
|
|
function Byte gf_add(Byte left, Byte right);
|
|
return (left ^ right);
|
|
endfunction
|
|
|
|
(* noinline *)
|
|
function Byte gf_add_inst(Byte x, Byte y);
|
|
return gf_add(x,y);
|
|
endfunction
|
|
|
|
|
|
// -----------------------------------------------------------
|
|
//(* noinline *)
|
|
function Byte alpha_n(Byte n);
|
|
return times_alpha_n(1,n);
|
|
endfunction
|
|
|
|
// -----------------------------------------------------------
|
|
//(* noinline *)
|
|
function Byte times_alpha_n(Byte a, Byte n);
|
|
// Byte multVal = 1 << n;
|
|
// return gf_mult(primitive_poly,a,multVal);
|
|
|
|
Byte b=a;
|
|
for (Byte i = 0; i < n; i = i + 1)
|
|
b=times_alpha(b);
|
|
return b;
|
|
endfunction
|
|
|
|
// -----------------------------------------------------------
|
|
//(* noinline *)
|
|
function Byte times_alpha(Byte a);
|
|
// return gf_mult(primitive_poly, a, 2);
|
|
|
|
return (a<<1)^({a[7],a[7],a[7],a[7],a[7],a[7],a[7],a[7]} & primitive_poly);
|
|
endfunction
|
|
|
|
// -----------------------------------------------------------
|
|
/*
|
|
function Byte gf_inv (Byte a);
|
|
|
|
case (a) matches
|
|
0 : return 2;
|
|
1 : return 1;
|
|
2 : return 142;
|
|
3 : return 244;
|
|
4 : return 71;
|
|
5 : return 167;
|
|
6 : return 122;
|
|
7 : return 186;
|
|
8 : return 173;
|
|
9 : return 157;
|
|
10 : return 221;
|
|
11 : return 152;
|
|
12 : return 61;
|
|
13 : return 170;
|
|
14 : return 93;
|
|
15 : return 150;
|
|
16 : return 216;
|
|
17 : return 114;
|
|
18 : return 192;
|
|
19 : return 88;
|
|
20 : return 224;
|
|
21 : return 62;
|
|
22 : return 76;
|
|
23 : return 102;
|
|
24 : return 144;
|
|
25 : return 222;
|
|
26 : return 85;
|
|
27 : return 128;
|
|
28 : return 160;
|
|
29 : return 131;
|
|
30 : return 75;
|
|
31 : return 42;
|
|
32 : return 108;
|
|
33 : return 237;
|
|
34 : return 57;
|
|
35 : return 81;
|
|
36 : return 96;
|
|
37 : return 86;
|
|
38 : return 44;
|
|
39 : return 138;
|
|
40 : return 112;
|
|
41 : return 208;
|
|
42 : return 31;
|
|
43 : return 74;
|
|
44 : return 38;
|
|
45 : return 139;
|
|
46 : return 51;
|
|
47 : return 110;
|
|
48 : return 72;
|
|
49 : return 137;
|
|
50 : return 111;
|
|
51 : return 46;
|
|
52 : return 164;
|
|
53 : return 195;
|
|
54 : return 64;
|
|
55 : return 94;
|
|
56 : return 80;
|
|
57 : return 34;
|
|
58 : return 207;
|
|
59 : return 169;
|
|
60 : return 171;
|
|
61 : return 12;
|
|
62 : return 21;
|
|
63 : return 225;
|
|
64 : return 54;
|
|
65 : return 95;
|
|
66 : return 248;
|
|
67 : return 213;
|
|
68 : return 146;
|
|
69 : return 78;
|
|
70 : return 166;
|
|
71 : return 4;
|
|
72 : return 48;
|
|
73 : return 136;
|
|
74 : return 43;
|
|
75 : return 30;
|
|
76 : return 22;
|
|
77 : return 103;
|
|
78 : return 69;
|
|
79 : return 147;
|
|
80 : return 56;
|
|
81 : return 35;
|
|
82 : return 104;
|
|
83 : return 140;
|
|
84 : return 129;
|
|
85 : return 26;
|
|
86 : return 37;
|
|
87 : return 97;
|
|
88 : return 19;
|
|
89 : return 193;
|
|
90 : return 203;
|
|
91 : return 99;
|
|
92 : return 151;
|
|
93 : return 14;
|
|
94 : return 55;
|
|
95 : return 65;
|
|
96 : return 36;
|
|
97 : return 87;
|
|
98 : return 202;
|
|
99 : return 91;
|
|
100 : return 185;
|
|
101 : return 196;
|
|
102 : return 23;
|
|
103 : return 77;
|
|
104 : return 82;
|
|
105 : return 141;
|
|
106 : return 239;
|
|
107 : return 179;
|
|
108 : return 32;
|
|
109 : return 236;
|
|
110 : return 47;
|
|
111 : return 50;
|
|
112 : return 40;
|
|
113 : return 209;
|
|
114 : return 17;
|
|
115 : return 217;
|
|
116 : return 233;
|
|
117 : return 251;
|
|
118 : return 218;
|
|
119 : return 121;
|
|
120 : return 219;
|
|
121 : return 119;
|
|
122 : return 6;
|
|
123 : return 187;
|
|
124 : return 132;
|
|
125 : return 205;
|
|
126 : return 254;
|
|
127 : return 252;
|
|
128 : return 27;
|
|
129 : return 84;
|
|
130 : return 161;
|
|
131 : return 29;
|
|
132 : return 124;
|
|
133 : return 204;
|
|
134 : return 228;
|
|
135 : return 176;
|
|
136 : return 73;
|
|
137 : return 49;
|
|
138 : return 39;
|
|
139 : return 45;
|
|
140 : return 83;
|
|
141 : return 105;
|
|
142 : return 2;
|
|
143 : return 245;
|
|
144 : return 24;
|
|
145 : return 223;
|
|
146 : return 68;
|
|
147 : return 79;
|
|
148 : return 155;
|
|
149 : return 188;
|
|
150 : return 15;
|
|
151 : return 92;
|
|
152 : return 11;
|
|
153 : return 220;
|
|
154 : return 189;
|
|
155 : return 148;
|
|
156 : return 172;
|
|
157 : return 9;
|
|
158 : return 199;
|
|
159 : return 162;
|
|
160 : return 28;
|
|
161 : return 130;
|
|
162 : return 159;
|
|
163 : return 198;
|
|
164 : return 52;
|
|
165 : return 194;
|
|
166 : return 70;
|
|
167 : return 5;
|
|
168 : return 206;
|
|
169 : return 59;
|
|
170 : return 13;
|
|
171 : return 60;
|
|
172 : return 156;
|
|
173 : return 8;
|
|
174 : return 190;
|
|
175 : return 183;
|
|
176 : return 135;
|
|
177 : return 229;
|
|
178 : return 238;
|
|
179 : return 107;
|
|
180 : return 235;
|
|
181 : return 242;
|
|
182 : return 191;
|
|
183 : return 175;
|
|
184 : return 197;
|
|
185 : return 100;
|
|
186 : return 7;
|
|
187 : return 123;
|
|
188 : return 149;
|
|
189 : return 154;
|
|
190 : return 174;
|
|
191 : return 182;
|
|
192 : return 18;
|
|
193 : return 89;
|
|
194 : return 165;
|
|
195 : return 53;
|
|
196 : return 101;
|
|
197 : return 184;
|
|
198 : return 163;
|
|
199 : return 158;
|
|
200 : return 210;
|
|
201 : return 247;
|
|
202 : return 98;
|
|
203 : return 90;
|
|
204 : return 133;
|
|
205 : return 125;
|
|
206 : return 168;
|
|
207 : return 58;
|
|
208 : return 41;
|
|
209 : return 113;
|
|
210 : return 200;
|
|
211 : return 246;
|
|
212 : return 249;
|
|
213 : return 67;
|
|
214 : return 215;
|
|
215 : return 214;
|
|
216 : return 16;
|
|
217 : return 115;
|
|
218 : return 118;
|
|
219 : return 120;
|
|
220 : return 153;
|
|
221 : return 10;
|
|
222 : return 25;
|
|
223 : return 145;
|
|
224 : return 20;
|
|
225 : return 63;
|
|
226 : return 230;
|
|
227 : return 240;
|
|
228 : return 134;
|
|
229 : return 177;
|
|
230 : return 226;
|
|
231 : return 241;
|
|
232 : return 250;
|
|
233 : return 116;
|
|
234 : return 243;
|
|
235 : return 180;
|
|
236 : return 109;
|
|
237 : return 33;
|
|
238 : return 178;
|
|
239 : return 106;
|
|
240 : return 227;
|
|
241 : return 231;
|
|
242 : return 181;
|
|
243 : return 234;
|
|
244 : return 3;
|
|
245 : return 143;
|
|
246 : return 211;
|
|
247 : return 201;
|
|
248 : return 66;
|
|
249 : return 212;
|
|
250 : return 232;
|
|
251 : return 117;
|
|
252 : return 127;
|
|
253 : return 255;
|
|
254 : return 126;
|
|
255 : return 253;
|
|
endcase
|
|
endfunction
|
|
*/
|
