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1 | // ========== Copyright Header Begin ========================================== |
2 | // | |
3 | // OpenSPARC T2 Processor File: MDIO2P_FRMR.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 | // Copyright (c) 2003 Texas Instruments, Inc. | |
38 | // All rights reserved | |
39 | // | |
40 | // This is an unpublished work created in the year stated above. | |
41 | // Texas Instruments owns all rights in and to the work and intends to | |
42 | // maintain it and protect it as unpublished copyright. In the event | |
43 | // of either inadvertant or deliberate publication, the above stated | |
44 | // date shall be treated as the year of first publication. In the event | |
45 | // of such publication, Texas Instruments intends to enforce its rights | |
46 | // in the work under the copyright laws as a published work. | |
47 | // | |
48 | // These commodities are under U.S. Government distribution license | |
49 | // control. As such, they are not be re-exported without prior approval | |
50 | // from the U.S. Department of Commerce. | |
51 | // | |
52 | //////////////////////////////////////////////////////////////////////////////// | |
53 | ||
54 | //////////////////////////////////////////////////////////////////////////////// | |
55 | // | |
56 | // FUNCTION: Identify MDIO Frames, and identify keys cycles within each | |
57 | // frame | |
58 | // COMMENTS: Uses a 6-bit LFSR to map out the MDIO frame. Cycles within the | |
59 | // frame are identified as follows: | |
60 | // | |
61 | // Cycle MDIO Code Parameter Comment | |
62 | // ----- ---- ------ --------- ------------------- | |
63 | // - 1 000000 frmr_WT >= 32 bits of preamble complete | |
64 | // - 1 110010 frmr_PRE Start of Preamble | |
65 | // 0 1 100100 . | |
66 | // 1 0/1 001001 frmr_SOF Clause specifier | |
67 | // 2 OP 010010 Opcode | |
68 | // 3 OP 100101 Opcode | |
69 | // 4 PA 001011 Port Address | |
70 | // 5 PA 010110 . | |
71 | // 6 PA 101101 . | |
72 | // 7 PA 011011 . | |
73 | // 8 PA 110111 . | |
74 | // 9 DA 101110 Device Address | |
75 | // 10 DA 011101 . | |
76 | // 11 DA 111011 . | |
77 | // 12 DA 110110 . | |
78 | // 13 DA 101100 . | |
79 | // 14 1/Z 011001 frmr_ADD Z on reads, 1 on writes | |
80 | // 15 0 110011 frmr_TA Turn around | |
81 | // 16 D 100110 Data | |
82 | // 17 D 001101 . | |
83 | // 18 D 011010 . | |
84 | // 19 D 110101 . | |
85 | // 20 D 101010 . | |
86 | // 21 D 010101 . | |
87 | // 22 D 101011 . | |
88 | // 23 D 010111 . | |
89 | // 24 D 101111 . | |
90 | // 25 D 011111 . | |
91 | // 26 D 111111 . | |
92 | // 27 D 111110 . | |
93 | // 28 D 111100 . | |
94 | // 29 D 111000 . | |
95 | // 30 D 110000 . | |
96 | // 31 D 100000 frmr_EOF End of frame | |
97 | // | |
98 | // VERSION: #VERSION# | |
99 | // DATE: #DATE# | |
100 | // | |
101 | // Date Author Changes | |
102 | // ------- ------ ----------------------------------------------------- | |
103 | // 27Jan05 Andre Asynchronous reset removed | |
104 | // | |
105 | //////////////////////////////////////////////////////////////////////////////// | |
106 | ||
107 | `timescale 1ns / 1ps | |
108 | ||
109 | module MDIO2P_FRMR | |
110 | ( | |
111 | IO_MDCLK, | |
112 | IO_RESET, | |
113 | MDIN, | |
114 | FRMR_STATE | |
115 | ); | |
116 | ||
117 | //////////////////////////////////////////////////////////////////////////////// | |
118 | // | |
119 | // Port Declarations | |
120 | // | |
121 | //////////////////////////////////////////////////////////////////////////////// | |
122 | ||
123 | input IO_RESET; // Global reset | |
124 | ||
125 | // MDIO Interface | |
126 | input IO_MDCLK; // Clock | |
127 | input MDIN; // Data in | |
128 | ||
129 | // Interface to Framer | |
130 | output[5:0] FRMR_STATE; // LFSR encoded frame state | |
131 | ||
132 | ||
133 | //////////////////////////////////////////////////////////////////////////////// | |
134 | // | |
135 | // Outputs which are not wires | |
136 | // | |
137 | //////////////////////////////////////////////////////////////////////////////// | |
138 | ||
139 | ||
140 | //////////////////////////////////////////////////////////////////////////////// | |
141 | // | |
142 | // Parameters for frame sequencing | |
143 | // | |
144 | //////////////////////////////////////////////////////////////////////////////// | |
145 | ||
146 | parameter frmr_WT = 6'b000000; | |
147 | parameter frmr_PRE = 6'b110010; | |
148 | parameter frmr_SOF = 6'b001001; | |
149 | parameter frmr_EOF = 6'b100000; | |
150 | ||
151 | ||
152 | //////////////////////////////////////////////////////////////////////////////// | |
153 | // | |
154 | // Internal Declarations | |
155 | // | |
156 | //////////////////////////////////////////////////////////////////////////////// | |
157 | ||
158 | // Flops | |
159 | reg[5:0] state; | |
160 | reg preamble; // Preamble in progress | |
161 | ||
162 | // Combinatorials | |
163 | wire frame_done; // EOF state decode | |
164 | wire preamble_done; // Preamble at least 32 cycles long | |
165 | ||
166 | ||
167 | //////////////////////////////////////////////////////////////////////////////// | |
168 | // | |
169 | // Framer | |
170 | // - Frame requires 32 states. | |
171 | // - Frames start with a 0 on MDIN, and can repeat back to back. | |
172 | // - Preamble is arbitrarily long, during which LFSR is held at zero. | |
173 | // - Starting position is chosen to make force to zero as simple as possible | |
174 | // | |
175 | //////////////////////////////////////////////////////////////////////////////// | |
176 | ||
177 | assign frame_done = (state == frmr_EOF); | |
178 | assign preamble_done = frame_done | (state == frmr_WT); | |
179 | ||
180 | always @(posedge IO_MDCLK) | |
181 | begin | |
182 | if(IO_RESET) | |
183 | begin | |
184 | state <= frmr_PRE; | |
185 | preamble <= 1'b1; | |
186 | end | |
187 | else if(preamble & ~preamble_done & ~MDIN) | |
188 | state <= frmr_PRE; | |
189 | else if(preamble & preamble_done & MDIN) | |
190 | state <= frmr_WT; | |
191 | else if(preamble & preamble_done & ~MDIN) | |
192 | begin | |
193 | state <= frmr_SOF; | |
194 | preamble <= ~preamble; | |
195 | end | |
196 | else if(frame_done) | |
197 | begin | |
198 | state <= frmr_PRE; | |
199 | preamble <= ~preamble; | |
200 | end | |
201 | else | |
202 | state <= {state[4:0], state[5] ^ state[4]}; | |
203 | end | |
204 | ||
205 | ||
206 | //////////////////////////////////////////////////////////////////////////////// | |
207 | // | |
208 | // Output Assignments | |
209 | // | |
210 | //////////////////////////////////////////////////////////////////////////////// | |
211 | ||
212 | assign FRMR_STATE = preamble ? 5'b0 : state; | |
213 | ||
214 | endmodule |