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1 | // ========== Copyright Header Begin ========================================== |
2 | // | |
3 | // OpenSPARC T2 Processor File: xpcs_rxio_ebuffer_sm.v | |
4 | // Copyright (C) 1995-2007 Sun Microsystems, Inc. All Rights Reserved | |
5 | // 4150 Network Circle, Santa Clara, California 95054, U.S.A. | |
6 | // | |
7 | // * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
8 | // | |
9 | // This program is free software; you can redistribute it and/or modify | |
10 | // it under the terms of the GNU General Public License as published by | |
11 | // the Free Software Foundation; version 2 of the License. | |
12 | // | |
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | // | |
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | // | |
22 | // For the avoidance of doubt, and except that if any non-GPL license | |
23 | // choice is available it will apply instead, Sun elects to use only | |
24 | // the General Public License version 2 (GPLv2) at this time for any | |
25 | // software where a choice of GPL license versions is made | |
26 | // available with the language indicating that GPLv2 or any later version | |
27 | // may be used, or where a choice of which version of the GPL is applied is | |
28 | // otherwise unspecified. | |
29 | // | |
30 | // Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
31 | // CA 95054 USA or visit www.sun.com if you need additional information or | |
32 | // have any questions. | |
33 | // | |
34 | // ========== Copyright Header End ============================================ | |
35 | // **************************************************************** | |
36 | // | |
37 | // Sun Proprietary/Confidential: Internal Use Only | |
38 | // | |
39 | // **************************************************************** | |
40 | // Design: Vega | |
41 | // Block: XPCS Lane-to-lane deskew Interface | |
42 | // Author: Carlos Castil | |
43 | // | |
44 | // Module: xpcs_rxio_ebuffer_sm | |
45 | // File: xpcs_rxio_ebuffer_sm.v | |
46 | // | |
47 | // Description: This block contains the deskew state machine | |
48 | // compliant to ieee 802.3ae clause 48 fig 48-8. | |
49 | // | |
50 | // Revision History | |
51 | // ------------------------------------------------------------ | |
52 | // Ver Date Comments | |
53 | // ------------------------------------------------------------ | |
54 | // 1.0 10/11/02 Created | |
55 | // | |
56 | // **************************************************************** | |
57 | ||
58 | ||
59 | module xpcs_rxio_ebuffer_sm ( | |
60 | ||
61 | reset, | |
62 | rx_clk, | |
63 | ||
64 | csr_pulse_deskew_error, | |
65 | csr_link_status, | |
66 | sync_status, | |
67 | ||
68 | state, | |
69 | ||
70 | deskew_init, | |
71 | deskew_done, | |
72 | ||
73 | r_byte_0, | |
74 | r_byte_1, | |
75 | r_byte_2, | |
76 | r_byte_3, | |
77 | ||
78 | r_special_0, | |
79 | r_special_1, | |
80 | r_special_2, | |
81 | r_special_3, | |
82 | ||
83 | r_error_0, | |
84 | r_error_1, | |
85 | r_error_2, | |
86 | r_error_3 ); | |
87 | ||
88 | input reset; | |
89 | input rx_clk; | |
90 | ||
91 | input [7:0] r_byte_0; | |
92 | input [7:0] r_byte_1; | |
93 | input [7:0] r_byte_2; | |
94 | input [7:0] r_byte_3; | |
95 | ||
96 | input r_special_0; | |
97 | input r_special_1; | |
98 | input r_special_2; | |
99 | input r_special_3; | |
100 | ||
101 | input r_error_0; | |
102 | input r_error_1; | |
103 | input r_error_2; | |
104 | input r_error_3; | |
105 | ||
106 | input deskew_done; | |
107 | ||
108 | input sync_status; | |
109 | ||
110 | output deskew_init; | |
111 | output [7:0] state; | |
112 | output csr_link_status; | |
113 | output csr_pulse_deskew_error; | |
114 | ||
115 | parameter DESKEW_LOSS = 8'h00; | |
116 | parameter ALIGN_DET1 = 8'h01; | |
117 | parameter ALIGN_DET2 = 8'h02; | |
118 | parameter ALIGN_DET3 = 8'h04; | |
119 | parameter DESKEW_OK = 8'h08; | |
120 | parameter ALIGN_ERR1 = 8'h10; | |
121 | parameter ALIGN_ERR2 = 8'h20; | |
122 | parameter ALIGN_ERR3 = 8'h40; | |
123 | ||
124 | wire [9:0] read_in_0; | |
125 | wire [9:0] read_in_1; | |
126 | wire [9:0] read_in_2; | |
127 | wire [9:0] read_in_3; | |
128 | ||
129 | wire alg_lane0; | |
130 | wire alg_lane1; | |
131 | wire alg_lane2; | |
132 | wire alg_lane3; | |
133 | ||
134 | wire alg_present; | |
135 | wire aligned; | |
136 | ||
137 | wire csr_deskew_error; | |
138 | wire got_deskew_ok; | |
139 | ||
140 | wire deskew_on_pulse; | |
141 | wire deskew_off_pulse; | |
142 | ||
143 | wire [7:0] nxt_state; | |
144 | ||
145 | reg [7:0] state; | |
146 | reg deskew_done_d; | |
147 | reg deskew_init_d; | |
148 | reg deskewing; | |
149 | ||
150 | // ************************************************************************ | |
151 | // Snoop data out of deskew fifo to check if align characters are deskewed | |
152 | // ************************************************************************ | |
153 | ||
154 | assign read_in_0[9:0] = {r_error_0, r_special_0, r_byte_0[7:0]}; | |
155 | assign read_in_1[9:0] = {r_error_1, r_special_1, r_byte_1[7:0]}; | |
156 | assign read_in_2[9:0] = {r_error_2, r_special_2, r_byte_2[7:0]}; | |
157 | assign read_in_3[9:0] = {r_error_3, r_special_3, r_byte_3[7:0]}; | |
158 | ||
159 | // check for comma symbol on all lanes | |
160 | ||
161 | assign alg_lane0 = (read_in_0[9:0] == `XPCS_DEC_ALG); | |
162 | assign alg_lane1 = (read_in_1[9:0] == `XPCS_DEC_ALG); | |
163 | assign alg_lane2 = (read_in_2[9:0] == `XPCS_DEC_ALG); | |
164 | assign alg_lane3 = (read_in_3[9:0] == `XPCS_DEC_ALG); | |
165 | ||
166 | assign alg_present = alg_lane0 | alg_lane1 | alg_lane2 | alg_lane3 ; | |
167 | ||
168 | assign aligned = alg_lane0 & alg_lane1 & alg_lane2 & alg_lane3; | |
169 | ||
170 | assign csr_deskew_error = alg_present & !aligned; | |
171 | ||
172 | assign got_deskew_ok = alg_present & aligned; | |
173 | ||
174 | // ******************************** | |
175 | // Deskew init and done handshake | |
176 | // ******************************** | |
177 | ||
178 | always @ (posedge rx_clk) | |
179 | if (reset) | |
180 | begin | |
181 | deskew_done_d <= 1'b0; | |
182 | deskew_init_d <= 1'b0; | |
183 | deskewing <= 1'b0; | |
184 | end | |
185 | else | |
186 | begin | |
187 | deskew_done_d <= deskew_done; | |
188 | deskew_init_d <= deskew_init; | |
189 | deskewing <= deskew_on_pulse ? 1'b1 : deskew_off_pulse ? 1'b0 : deskewing; | |
190 | end | |
191 | ||
192 | assign deskew_off_pulse = deskew_done & !deskew_done_d; | |
193 | assign deskew_on_pulse = deskew_init & !deskew_init_d; | |
194 | ||
195 | ||
196 | // ***************************************** | |
197 | // Deskew state machine Clause 48 fig 48-8 | |
198 | // ***************************************** | |
199 | ||
200 | always @ (posedge rx_clk) | |
201 | if (reset) | |
202 | state <= 8'h00; | |
203 | else | |
204 | state <= nxt_state; | |
205 | ||
206 | ||
207 | wire csr_link_status_temp; | |
208 | reg csr_link_status; | |
209 | ||
210 | always @ (posedge rx_clk) | |
211 | csr_link_status <= csr_link_status_temp; | |
212 | ||
213 | assign {csr_link_status_temp, | |
214 | csr_pulse_deskew_error, | |
215 | deskew_init, | |
216 | nxt_state} = fn_deskew_sm (reset, | |
217 | state, | |
218 | sync_status, | |
219 | csr_deskew_error, | |
220 | deskewing, | |
221 | got_deskew_ok); | |
222 | ||
223 | function [10:0] fn_deskew_sm; | |
224 | ||
225 | input reset; | |
226 | input [7:0] state; | |
227 | input sync; | |
228 | input error; | |
229 | input deskewing; | |
230 | input got_ok; | |
231 | ||
232 | reg [7:0] n_state; | |
233 | reg n_status; | |
234 | reg n_init; | |
235 | reg n_inc_deskew_error; | |
236 | ||
237 | begin | |
238 | ||
239 | if (reset | !sync) | |
240 | begin | |
241 | n_status = 1'b0; | |
242 | n_init = 1'b0; | |
243 | n_inc_deskew_error = 1'b0; | |
244 | n_state = DESKEW_LOSS; | |
245 | end | |
246 | ||
247 | else | |
248 | ||
249 | begin | |
250 | n_status = 1'b0; | |
251 | n_init = 1'b0; | |
252 | n_inc_deskew_error = 1'b0; | |
253 | n_state = DESKEW_LOSS; | |
254 | ||
255 | case (state) // synopsys parallel_case | |
256 | ||
257 | DESKEW_LOSS: | |
258 | ||
259 | if (!sync) | |
260 | begin | |
261 | n_init = 1'b0; | |
262 | n_state = DESKEW_LOSS; | |
263 | end | |
264 | ||
265 | else if (got_ok) | |
266 | begin | |
267 | n_init = 1'b0; | |
268 | n_state = ALIGN_DET1; | |
269 | end | |
270 | ||
271 | else if (!deskewing) | |
272 | begin | |
273 | n_init = 1'b1; | |
274 | n_state = DESKEW_LOSS; | |
275 | end | |
276 | ||
277 | else | |
278 | begin | |
279 | n_init = 1'b0; | |
280 | n_state = DESKEW_LOSS; | |
281 | end | |
282 | ||
283 | ALIGN_DET1: | |
284 | ||
285 | if (error) | |
286 | begin | |
287 | n_state = DESKEW_LOSS; | |
288 | end | |
289 | ||
290 | else if (got_ok) | |
291 | begin | |
292 | n_state = ALIGN_DET2; | |
293 | end | |
294 | ||
295 | else | |
296 | begin | |
297 | n_state = ALIGN_DET1; | |
298 | end | |
299 | ||
300 | ALIGN_DET2: | |
301 | ||
302 | if (error) | |
303 | begin | |
304 | n_state = DESKEW_LOSS; | |
305 | end | |
306 | ||
307 | else if (got_ok) | |
308 | begin | |
309 | n_state = ALIGN_DET3; | |
310 | end | |
311 | ||
312 | else | |
313 | begin | |
314 | n_state = ALIGN_DET2; | |
315 | end | |
316 | ||
317 | ALIGN_DET3: | |
318 | ||
319 | if (error) | |
320 | begin | |
321 | n_state = DESKEW_LOSS; | |
322 | end | |
323 | ||
324 | else if (got_ok) | |
325 | begin | |
326 | n_state = DESKEW_OK; | |
327 | end | |
328 | ||
329 | else | |
330 | begin | |
331 | n_state = ALIGN_DET3; | |
332 | end | |
333 | ||
334 | DESKEW_OK: | |
335 | ||
336 | if (error) | |
337 | begin | |
338 | n_status = 1'b1; | |
339 | n_state = ALIGN_ERR1; | |
340 | end | |
341 | ||
342 | else | |
343 | begin | |
344 | n_status = 1'b1; | |
345 | n_state = DESKEW_OK; | |
346 | end | |
347 | ||
348 | ||
349 | ALIGN_ERR1: | |
350 | ||
351 | if (error) | |
352 | begin | |
353 | n_status = 1'b1; | |
354 | n_state = ALIGN_ERR2; | |
355 | end | |
356 | ||
357 | else if (got_ok) | |
358 | begin | |
359 | n_status = 1'b1; | |
360 | n_state = DESKEW_OK; | |
361 | end | |
362 | ||
363 | else | |
364 | begin | |
365 | n_status = 1'b1; | |
366 | n_state = ALIGN_ERR1; | |
367 | end | |
368 | ||
369 | ALIGN_ERR2: | |
370 | ||
371 | if (error) | |
372 | begin | |
373 | n_status = 1'b1; | |
374 | n_state = ALIGN_ERR3; | |
375 | end | |
376 | ||
377 | else if (got_ok) | |
378 | begin | |
379 | n_status = 1'b1; | |
380 | n_state = ALIGN_ERR1; | |
381 | end | |
382 | ||
383 | else | |
384 | begin | |
385 | n_status = 1'b1; | |
386 | n_state = ALIGN_ERR2; | |
387 | end | |
388 | ||
389 | ALIGN_ERR3: | |
390 | ||
391 | if (error) | |
392 | begin | |
393 | n_status = 1'b1; | |
394 | n_inc_deskew_error = 1'b0; | |
395 | n_state = DESKEW_LOSS; | |
396 | end | |
397 | ||
398 | else if (got_ok) | |
399 | begin | |
400 | n_status = 1'b1; | |
401 | n_state = ALIGN_ERR2; | |
402 | end | |
403 | ||
404 | else | |
405 | begin | |
406 | n_status = 1'b1; | |
407 | n_state = ALIGN_ERR3; | |
408 | end | |
409 | ||
410 | endcase | |
411 | ||
412 | end | |
413 | ||
414 | fn_deskew_sm = {n_status, n_inc_deskew_error, n_init, n_state}; | |
415 | ||
416 | end | |
417 | ||
418 | endfunction | |
419 | ||
420 | ||
421 | // 0in bits_on -var state -max 1 -clock rx_clk | |
422 | ||
423 | // 0in state -var state -val DESKEW_LOSS -next ALIGN_DET1 -clock rx_clk -reset (reset |!sync_status) | |
424 | // 0in state -var state -val ALIGN_DET1 -next DESKEW_LOSS ALIGN_DET2 -clock rx_clk -reset (reset |!sync_status) | |
425 | // 0in state -var state -val ALIGN_DET2 -next DESKEW_LOSS ALIGN_DET3 -clock rx_clk -reset (reset |!sync_status) | |
426 | // 0in state -var state -val ALIGN_DET3 -next DESKEW_LOSS DESKEW_OK -clock rx_clk -reset (reset |!sync_status) | |
427 | // 0in state -var state -val DESKEW_OK -next ALIGN_ERR1 -clock rx_clk -reset (reset |!sync_status) | |
428 | // 0in state -var state -val ALIGN_ERR1 -next DESKEW_OK ALIGN_ERR2 -clock rx_clk -reset (reset |!sync_status) | |
429 | // 0in state -var state -val ALIGN_ERR2 -next ALIGN_ERR3 ALIGN_ERR1 -clock rx_clk -reset (reset |!sync_status) | |
430 | // 0in state -var state -val ALIGN_ERR3 -next DESKEW_LOSS ALIGN_ERR2 -clock rx_clk -reset (reset |!sync_status) | |
431 | ||
432 | ||
433 | endmodule | |
434 |