OpenCores
URL https://opencores.org/ocsvn/apbtoaes128/apbtoaes128/trunk

Subversion Repositories apbtoaes128

[/] [apbtoaes128/] [trunk/] [rtl/] [control_unit.v] - Blame information for rev 2

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 redbear
//////////////////////////////////////////////////////////////////
2
////
3
////
4
////    AES CORE BLOCK
5
////
6
////
7
////
8
//// This file is part of the APB to I2C project
9
////
10
//// http://www.opencores.org/cores/apbi2c/
11
////
12
////
13
////
14
//// Description
15
////
16
//// Implementation of APB IP core according to
17
////
18
//// aes128_spec IP core specification document.
19
////
20
////
21
////
22
//// To Do: Things are right here but always all block can suffer changes
23
////
24
////
25
////
26
////
27
////
28
//// Author(s): - Felipe Fernandes Da Costa, fefe2560@gmail.com
29
////              Julio Cesar 
30
////
31
///////////////////////////////////////////////////////////////// 
32
////
33
////
34
//// Copyright (C) 2009 Authors and OPENCORES.ORG
35
////
36
////
37
////
38
//// This source file may be used and distributed without
39
////
40
//// restriction provided that this copyright statement is not
41
////
42
//// removed from the file and that any derivative work contains
43
//// the original copyright notice and the associated disclaimer.
44
////
45
////
46
//// This source file is free software; you can redistribute it
47
////
48
//// and/or modify it under the terms of the GNU Lesser General
49
////
50
//// Public License as published by the Free Software Foundation;
51
//// either version 2.1 of the License, or (at your option) any
52
////
53
//// later version.
54
////
55
////
56
////
57
//// This source is distributed in the hope that it will be
58
////
59
//// useful, but WITHOUT ANY WARRANTY; without even the implied
60
////
61
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
62
////
63
//// PURPOSE. See the GNU Lesser General Public License for more
64
//// details.
65
////
66
////
67
////
68
//// You should have received a copy of the GNU Lesser General
69
////
70
//// Public License along with this source; if not, download it
71
////
72
//// from http://www.opencores.org/lgpl.shtml
73
////
74
////
75
///////////////////////////////////////////////////////////////////
76
module control_unit
77
(
78
        output reg [ 2:0] sbox_sel,
79
        output reg [ 1:0] rk_sel,
80
        output reg [ 1:0] key_out_sel,
81
        output reg [ 1:0] col_sel,
82
        output reg [ 3:0] key_en,
83
        output reg [ 3:0] col_en,
84
        output     [ 3:0] round,
85
        output reg bypass_rk,
86
        output reg bypass_key_en,
87
        output reg key_sel,
88
        output reg iv_cnt_en,
89
        output reg iv_cnt_sel,
90
        output reg key_derivation_en,
91
        output reg end_comp,
92
        output key_init,
93
        output key_gen,
94
        output mode_ctr,
95
        output mode_cbc,
96
        output last_round,
97
  output encrypt_decrypt,
98
        input [1:0] operation_mode,
99
        input [1:0] aes_mode,
100
        input start,
101
        input disable_core,
102
        input clk,
103
        input rst_n
104
);
105
//`include "include/host_interface.vh"
106
//`include "include/control_unit_params.vh"
107
 
108
//=====================================================================================
109
// Memory Mapped Registers Address
110
//=====================================================================================
111
localparam AES_CR    = 4'd00;
112
localparam AES_SR    = 4'd01;
113
localparam AES_DINR  = 4'd02;
114
localparam AES_DOUTR = 4'd03;
115
localparam AES_KEYR0 = 4'd04;
116
localparam AES_KEYR1 = 4'd05;
117
localparam AES_KEYR2 = 4'd06;
118
localparam AES_KEYR3 = 4'd07;
119
localparam AES_IVR0  = 4'd08;
120
localparam AES_IVR1  = 4'd09;
121
localparam AES_IVR2  = 4'd10;
122
localparam AES_IVR3  = 4'd11;
123
 
124
//=============================================================================
125
// Operation Modes
126
//=============================================================================
127
localparam ENCRYPTION     = 2'b00;
128
localparam KEY_DERIVATION = 2'b01;
129
localparam DECRYPTION     = 2'b10;
130
localparam DECRYP_W_DERIV = 2'b11;
131
 
132
//=============================================================================
133
// AES Modes
134
//=============================================================================
135
localparam ECB = 2'b00;
136
localparam CBC = 2'b01;
137
localparam CTR = 2'b10;
138
 
139
//=============================================================================
140
// SBOX SEL
141
//=============================================================================
142
localparam COL_0 = 3'b000;
143
localparam COL_1 = 3'b001;
144
localparam COL_2 = 3'b010;
145
localparam COL_3 = 3'b011;
146
localparam G_FUNCTION = 3'b100;
147
 
148
//=============================================================================
149
// RK_SEL
150
//=============================================================================
151
localparam COL        = 2'b00;
152
localparam MIXCOL_IN  = 2'b01;
153
localparam MIXCOL_OUT = 2'b10;
154
 
155
//=============================================================================
156
// KEY_OUT_SEL
157
//=============================================================================
158
localparam KEY_0 = 2'b00;
159
localparam KEY_1 = 2'b01;
160
localparam KEY_2 = 2'b10;
161
localparam KEY_3 = 2'b11;
162
 
163
//=============================================================================
164
// COL_SEL
165
//=============================================================================
166
localparam SHIFT_ROWS = 2'b00;
167
localparam ADD_RK_OUT = 2'b01;
168
localparam INPUT      = 2'b10;
169
 
170
//=============================================================================
171
// KEY_SEL
172
//=============================================================================
173
localparam KEY_HOST = 1'b0;
174
localparam KEY_OUT  = 1'b1;
175
 
176
//=============================================================================
177
// KEY_EN
178
//=============================================================================
179
localparam KEY_DIS  = 4'b0000;
180
localparam EN_KEY_0 = 4'b0001;
181
localparam EN_KEY_1 = 4'b0010;
182
localparam EN_KEY_2 = 4'b0100;
183
localparam EN_KEY_3 = 4'b1000;
184
localparam KEY_ALL  = 4'b1111;
185
 
186
//=============================================================================
187
// COL_EN
188
//=============================================================================
189
localparam COL_DIS  = 4'b0000;
190
localparam EN_COL_0 = 4'b0001;
191
localparam EN_COL_1 = 4'b0010;
192
localparam EN_COL_2 = 4'b0100;
193
localparam EN_COL_3 = 4'b1000;
194
localparam COL_ALL  = 4'b1111;
195
 
196
//=============================================================================
197
// IV_CNT_SEL
198
//=============================================================================
199
localparam IV_CNT = 1'b1;
200
localparam IV_BUS = 1'b0;
201
 
202
//=============================================================================
203
// ENABLES
204
//=============================================================================
205
localparam ENABLE = 1'b1;
206
localparam DISABLE = 1'b0;
207
 
208
localparam NUMBER_ROUND      = 4'd10;
209
localparam NUMBER_ROUND_INC  = 4'd11;
210
localparam INITIAL_ROUND     = 4'd00;
211
 
212
//=============================================================================
213
// FSM STATES
214
//=============================================================================
215
localparam IDLE        = 4'd00;
216
localparam ROUND0_COL0 = 4'd01;
217
localparam ROUND0_COL1 = 4'd02;
218
localparam ROUND0_COL2 = 4'd03;
219
localparam ROUND0_COL3 = 4'd04;
220
localparam ROUND_KEY0  = 4'd05;
221
localparam ROUND_COL0  = 4'd06;
222
localparam ROUND_COL1  = 4'd07;
223
localparam ROUND_COL2  = 4'd08;
224
localparam ROUND_COL3  = 4'd09;
225
localparam READY       = 4'd10;
226
localparam GEN_KEY0    = 4'd11;
227
localparam GEN_KEY1    = 4'd12;
228
localparam GEN_KEY2    = 4'd13;
229
localparam GEN_KEY3    = 4'd14;
230
localparam NOP         = 4'd15;
231
 
232
reg [3:0] state, next_state;
233
reg [3:0] rd_count;
234
 
235
reg rd_count_en;
236
wire op_key_derivation;
237
wire first_round;
238
wire [1:0] op_mode;
239
 
240
// State Flops Definition
241
always @(posedge clk, negedge rst_n)
242
        begin
243
                if(!rst_n)
244
                        state <= IDLE;
245
                else
246
                        if(disable_core)
247
                                state <= IDLE;
248
                        else
249
                                state <= next_state;
250
        end
251
 
252
assign encrypt_decrypt = (op_mode == ENCRYPTION || op_mode == KEY_DERIVATION ||
253
                                                                                                                state == GEN_KEY0   ||   state == GEN_KEY1       ||
254
                                                                                                                state == GEN_KEY2   ||   state == GEN_KEY3       );
255
 
256
assign enc_dec = encrypt_decrypt | mode_ctr;
257
assign key_gen = (state == ROUND_KEY0);
258
 
259
assign op_key_derivation = (op_mode == KEY_DERIVATION);
260
 
261
assign mode_ctr = (aes_mode == CTR);
262
assign mode_cbc = (aes_mode == CBC);
263
 
264
assign key_init = start;
265
 
266
assign op_mode = (mode_ctr) ? ENCRYPTION : operation_mode;
267
 
268
// Next State Logic
269
always @(*)
270
        begin
271
                next_state = state;
272
                case(state)
273
                        IDLE:
274
                                begin
275
                                        if(!start)
276
                                                next_state = IDLE;
277
                                        else
278
                                                case(op_mode)
279
                                                        ENCRYPTION    : next_state = ROUND0_COL0;
280
                                                        DECRYPTION    : next_state = ROUND0_COL3;
281
                                                        KEY_DERIVATION: next_state = GEN_KEY0;
282
                                                        DECRYP_W_DERIV: next_state = GEN_KEY0;
283
                                                        default       : next_state = IDLE;
284
                                                endcase
285
                                end
286
                        ROUND0_COL0:
287
                                begin
288
                                        next_state = (enc_dec) ? ROUND0_COL1 : ROUND_KEY0;
289
                                end
290
                        ROUND0_COL1:
291
                                begin
292
                                        next_state = (enc_dec) ? ROUND0_COL2 : ROUND0_COL0;
293
                                end
294
                        ROUND0_COL2:
295
                                begin
296
                                        next_state = (enc_dec) ? ROUND0_COL3 : ROUND0_COL1;
297
                                end
298
                        ROUND0_COL3:
299
                                begin
300
                                        next_state = (enc_dec) ? ROUND_KEY0 : ROUND0_COL2;
301
                                end
302
                        ROUND_KEY0 :
303
                                begin
304
                                        if(!first_round)
305
                                                begin
306
                                                        next_state = (last_round) ? READY : NOP;
307
                                                end
308
                                        else
309
                                                begin
310
                                                        next_state = (enc_dec) ? ROUND_COL0 : ROUND_COL3;
311
                                                end
312
                                end
313
                        NOP        :
314
                                begin
315
                                        next_state = (enc_dec) ? ROUND_COL0 : ROUND_COL3;
316
                                end
317
                        ROUND_COL0 :
318
                                begin
319
                                        next_state = (enc_dec) ? ROUND_COL1 : ROUND_KEY0;
320
                                end
321
                        ROUND_COL1 :
322
                                begin
323
                                        next_state = (enc_dec) ? ROUND_COL2 : ROUND_COL0;
324
                                end
325
                        ROUND_COL2 :
326
                                begin
327
                                        next_state = (enc_dec) ? ROUND_COL3 : ROUND_COL1;
328
                                end
329
                        ROUND_COL3 :
330
                                begin
331
                                        if(last_round && enc_dec)
332
                                                next_state = READY;
333
                                        else
334
                                        next_state = (enc_dec) ? ROUND_KEY0 : ROUND_COL2;
335
                                end
336
                        GEN_KEY0   :
337
                                begin
338
                                        next_state = GEN_KEY1;
339
                                end
340
                        GEN_KEY1   :
341
                                begin
342
                                        next_state = GEN_KEY2;
343
                                end
344
                        GEN_KEY2   :
345
                                begin
346
                                        next_state = GEN_KEY3;
347
                                end
348
                        GEN_KEY3   :
349
                                begin
350
                                        if(last_round)
351
                                                next_state = (op_key_derivation) ? READY : ROUND0_COL3;
352
                                        else
353
                                                next_state = GEN_KEY0;
354
                                end
355
                        READY      :
356
                                begin
357
                                        next_state = IDLE;
358
                                end
359
                endcase
360
        end
361
 
362
 
363
// Output Logic
364
always @(*)
365
        begin
366
                sbox_sel = COL_0;
367
                rk_sel = COL;
368
                bypass_rk = DISABLE;
369
                key_out_sel = KEY_0;
370
                col_sel = INPUT;
371
                key_sel = KEY_HOST;
372
                key_en = KEY_DIS;
373
                col_en = COL_DIS;
374
                rd_count_en = DISABLE;
375
                iv_cnt_en = DISABLE;
376
                iv_cnt_sel = IV_BUS;
377
                bypass_key_en = DISABLE;
378
                key_derivation_en = DISABLE;
379
                end_comp = DISABLE;
380
                case(state)
381
                        ROUND0_COL0:
382
                                begin
383
                                        sbox_sel = COL_0;
384
                                        rk_sel   = COL;
385
                                        bypass_rk = ENABLE;
386
                                        bypass_key_en = ENABLE;
387
                                        key_out_sel = KEY_0;
388
                                        col_sel = (enc_dec) ? ADD_RK_OUT : SHIFT_ROWS;
389
                                        col_en =  (enc_dec) ? EN_COL_0 : COL_ALL;
390
                                end
391
                        ROUND0_COL1:
392
                                begin
393
                                        sbox_sel = COL_1;
394
                                        rk_sel   = COL;
395
                                        bypass_rk = ENABLE;
396
                                        bypass_key_en = ENABLE;
397
                                        key_out_sel = KEY_1;
398
                                        col_sel = ADD_RK_OUT;
399
                                        col_en = EN_COL_1;
400
                                        if(!enc_dec)
401
                                                begin
402
                                                        key_sel = KEY_OUT;
403
                                                        key_en =  EN_KEY_1;
404
                                                end
405
                                end
406
                        ROUND0_COL2:
407
                                begin
408
                                        sbox_sel = COL_2;
409
                                        rk_sel   = COL;
410
                                        bypass_rk = ENABLE;
411
                                        bypass_key_en = ENABLE;
412
                                        key_out_sel = KEY_2;
413
                                        col_sel = ADD_RK_OUT;
414
                                        col_en = EN_COL_2;
415
                                        if(!enc_dec)
416
                                                begin
417
                                                        key_sel = KEY_OUT;
418
                                                        key_en =  EN_KEY_2;
419
                                                end
420
                                end
421
                        ROUND0_COL3:
422
                                begin
423
                                        sbox_sel = COL_3;
424
                                        rk_sel   = COL;
425
                                        bypass_key_en = ENABLE;
426
                                        key_out_sel = KEY_3;
427
                                        col_sel = (enc_dec) ? SHIFT_ROWS : ADD_RK_OUT;
428
                                        col_en =  (enc_dec) ? COL_ALL : EN_COL_3;
429
                                        bypass_rk = ENABLE;
430
                                        if(!enc_dec)
431
                                                begin
432
                                                        key_sel = KEY_OUT;
433
                                                        key_en =  EN_KEY_3;
434
                                                end
435
                                end
436
                        ROUND_KEY0:
437
                                begin
438
                                        sbox_sel = G_FUNCTION;
439
                                        key_sel = KEY_OUT;
440
                                        key_en = EN_KEY_0;
441
                                        rd_count_en = ENABLE;
442
                                end
443
                        ROUND_COL0:
444
                                begin
445
                                        sbox_sel = COL_0;
446
                                        rk_sel = (last_round) ? MIXCOL_IN : MIXCOL_OUT;
447
                                        key_out_sel = KEY_0;
448
                                        key_sel = KEY_OUT;
449
                                        if(enc_dec)
450
                                                key_en = EN_KEY_1;
451
                                        if((mode_cbc && last_round && !enc_dec) || (mode_ctr && last_round))
452
                                                col_sel = INPUT;
453
                                        else
454
                                                begin
455
                                                        if(!enc_dec)
456
                                                                col_sel = (last_round) ? ADD_RK_OUT : SHIFT_ROWS;
457
                                                        else
458
                                                                col_sel = ADD_RK_OUT;
459
                                                end
460
                                        if(enc_dec)
461
                                                col_en = EN_COL_0;
462
                                        else
463
                                                col_en = (last_round) ? EN_COL_0 : COL_ALL;
464
                                end
465
                        ROUND_COL1:
466
                                begin
467
                                        sbox_sel = COL_1;
468
                                        rk_sel   = (last_round) ? MIXCOL_IN : MIXCOL_OUT;
469
                                        key_out_sel = KEY_1;
470
                                        key_sel = KEY_OUT;
471
                                        if(enc_dec)
472
                                                key_en = EN_KEY_2;
473
                                        else
474
                                                key_en = EN_KEY_1;
475
                                        if((mode_cbc && last_round && !enc_dec) || (mode_ctr && last_round))
476
                                                col_sel = INPUT;
477
                                        else
478
                                                col_sel = ADD_RK_OUT;
479
                                        col_en = EN_COL_1;
480
                                end
481
                        ROUND_COL2:
482
                                begin
483
                                        sbox_sel = COL_2;
484
                                        rk_sel   = (last_round) ? MIXCOL_IN : MIXCOL_OUT;
485
                                        key_out_sel = KEY_2;
486
                                        key_sel = KEY_OUT;
487
                                        if(enc_dec)
488
                                                key_en = EN_KEY_3;
489
                                        else
490
                                                key_en = EN_KEY_2;
491
                                        if((mode_cbc && last_round && !enc_dec) || (mode_ctr && last_round))
492
                                                col_sel = INPUT;
493
                                        else
494
                                                col_sel = ADD_RK_OUT;
495
                                        col_en = EN_COL_2;
496
                                end
497
                        ROUND_COL3:
498
                                begin
499
                                        sbox_sel = COL_3;
500
                                        rk_sel   = (last_round) ? MIXCOL_IN : MIXCOL_OUT;
501
                                        key_out_sel = KEY_3;
502
                                        key_sel = KEY_OUT;
503
                                        if(!enc_dec)
504
                                                key_en = EN_KEY_3;
505
                                        if((mode_cbc && last_round && !enc_dec) || (mode_ctr && last_round))
506
                                                col_sel = INPUT;
507
                                        else
508
                                                begin
509
                                                        if(enc_dec)
510
                                                                col_sel = (last_round) ? ADD_RK_OUT : SHIFT_ROWS;
511
                                                        else
512
                                                                col_sel = ADD_RK_OUT;
513
                                                end
514
                                        if(enc_dec)
515
                                                col_en = (last_round) ? EN_COL_3 : COL_ALL;
516
                                        else
517
                                                col_en = EN_COL_3;
518
                                        if(mode_ctr && last_round)
519
                                                begin
520
                                                        iv_cnt_en = ENABLE;
521
                                                        iv_cnt_sel = IV_CNT;
522
                                                end
523
                                end
524
                        GEN_KEY0:
525
                                begin
526
                                        sbox_sel = G_FUNCTION;
527
                                        rd_count_en = ENABLE;
528
                                end
529
                        GEN_KEY1:
530
                                begin
531
                                        key_en = EN_KEY_1 | EN_KEY_0; //Enable key 0 AND key 1
532
                                        key_sel = KEY_OUT;
533
                                        bypass_key_en = ENABLE;
534
                                end
535
                        GEN_KEY2:
536
                                begin
537
                                        key_en = EN_KEY_2;
538
                                        key_sel = KEY_OUT;
539
                                        bypass_key_en = ENABLE;
540
                                end
541
                        GEN_KEY3:
542
                                begin
543
                                        key_en = EN_KEY_3;
544
                                        key_sel = KEY_OUT;
545
                                        bypass_key_en = ENABLE;
546
                                end
547
                        READY:
548
                                begin
549
                                        end_comp = ENABLE;
550
                                        if(op_mode == KEY_DERIVATION)
551
                                                key_derivation_en = ENABLE;
552
                                end
553
                endcase
554
        end
555
 
556
// Round Counter
557
always @(posedge clk, negedge rst_n)
558
        begin
559
                if(!rst_n)
560
                        rd_count <= INITIAL_ROUND;
561
                else
562
                        if(state == IDLE || (state == GEN_KEY3 && last_round))
563
                                rd_count <= INITIAL_ROUND;
564
                        else
565
                                if(rd_count_en)
566
                                        rd_count <= rd_count + 1'b1;
567
        end
568
 
569
assign round = rd_count;
570
assign first_round = (rd_count == INITIAL_ROUND);
571
assign last_round  = (rd_count == NUMBER_ROUND || rd_count == NUMBER_ROUND_INC);
572
 
573
endmodule

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.