Commit | Line | Data |
---|---|---|
86530b38 AT |
1 | // ========== Copyright Header Begin ========================================== |
2 | // | |
3 | // OpenSPARC T2 Processor File: fflp_fcram_arb.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 | /*project name: NIU */ | |
37 | /*module name: fflp_fcram_arb */ | |
38 | /*description: Aabitration between CPU access and flow */ | |
39 | /* classification */ | |
40 | /* */ | |
41 | /*child modules in: none */ | |
42 | /*interface modules: */ | |
43 | /*author name: Jeanne Cai */ | |
44 | /*date created: 16-03-2004 */ | |
45 | /* */ | |
46 | /* Copyright (c) 2004, Sun Microsystems, Inc. */ | |
47 | /* Sun Proprietary and Confidential */ | |
48 | /* */ | |
49 | /*modifications: */ | |
50 | /**********************************************************************/ | |
51 | ||
52 | ||
53 | module fflp_fcram_arb | |
54 | ( | |
55 | cclk, | |
56 | reset, | |
57 | fcram_lookup_ratio, | |
58 | fc_lookup_req, | |
59 | fwd_no_fc_sched_sm, | |
60 | cpu_fcram_req_sync, | |
61 | srch_burst_done, | |
62 | cpu_burst_done_sm, | |
63 | ||
64 | fwd_sched, | |
65 | do_srch_cycle, | |
66 | do_cpu_cycle, | |
67 | fc_fifo_ren | |
68 | ); | |
69 | ||
70 | input cclk; | |
71 | input reset; | |
72 | input[3:0] fcram_lookup_ratio; | |
73 | input fc_lookup_req; | |
74 | input fwd_no_fc_sched_sm; | |
75 | input cpu_fcram_req_sync; | |
76 | input srch_burst_done; | |
77 | input cpu_burst_done_sm; | |
78 | ||
79 | output fwd_sched; | |
80 | output do_srch_cycle; | |
81 | output do_cpu_cycle; | |
82 | output fc_fifo_ren; | |
83 | ||
84 | reg fwd_fc_sched_sm; | |
85 | reg cpu_sched_sm; | |
86 | reg[1:0] next_state; | |
87 | ||
88 | wire fwd_sched_in; | |
89 | wire fwd_sched; | |
90 | wire fwd_fc_sched; | |
91 | wire cpu_sched; | |
92 | wire fwd_sched_cnt_en; | |
93 | wire[3:0] fwd_sched_cnt_in; | |
94 | wire[3:0] fwd_sched_cnt; | |
95 | wire fwd_reqs_served; | |
96 | wire[1:0] state; | |
97 | ||
98 | wire cpu_fcram_req_sync_d; | |
99 | wire cpu_req_pulse; | |
100 | wire is_cpu_req_en; | |
101 | wire is_cpu_req_in; | |
102 | wire is_cpu_req; | |
103 | ||
104 | wire do_srch_cycle_en; | |
105 | wire do_srch_cycle_in; | |
106 | wire do_srch_cycle; | |
107 | wire do_cpu_cycle_en; | |
108 | wire do_cpu_cycle_in; | |
109 | wire do_cpu_cycle; | |
110 | ||
111 | wire fwd_sched_1; | |
112 | wire fwd_sched_2; | |
113 | wire fc_fifo_ren_in; | |
114 | wire fc_fifo_ren; | |
115 | ||
116 | //state machine states | |
117 | parameter | |
118 | FWD_ARB = 2'b00, | |
119 | FWD_IDLE = 2'b01, | |
120 | CPU_ARB = 2'b10, | |
121 | CPU_IDLE = 2'b11; | |
122 | ||
123 | always @ (state or fc_lookup_req or is_cpu_req or | |
124 | srch_burst_done or cpu_burst_done_sm or | |
125 | do_cpu_cycle or fwd_reqs_served) | |
126 | ||
127 | begin | |
128 | ||
129 | fwd_fc_sched_sm = 1'b0; | |
130 | cpu_sched_sm = 1'b0; | |
131 | next_state = 2'b0; | |
132 | ||
133 | case (state) //synopsys parallel_case full_case | |
134 | // 0in < case -full -parallel -message "0in ERROR: case check in fflp_fcram_arb:state" | |
135 | ||
136 | FWD_ARB: | |
137 | begin | |
138 | if (do_cpu_cycle & !cpu_burst_done_sm) | |
139 | begin | |
140 | fwd_fc_sched_sm = 1'b0; | |
141 | cpu_sched_sm = 1'b0; | |
142 | next_state = state; | |
143 | end | |
144 | else if (fc_lookup_req) | |
145 | begin | |
146 | fwd_fc_sched_sm = 1'b1; | |
147 | next_state = FWD_IDLE; | |
148 | end | |
149 | else if (is_cpu_req) | |
150 | begin | |
151 | cpu_sched_sm = 1'b1; | |
152 | next_state = CPU_IDLE; | |
153 | end | |
154 | else | |
155 | next_state = state; | |
156 | ||
157 | end | |
158 | ||
159 | FWD_IDLE: | |
160 | begin | |
161 | if (srch_burst_done & fwd_reqs_served) | |
162 | next_state = CPU_ARB; | |
163 | else if (srch_burst_done) | |
164 | next_state = FWD_ARB; | |
165 | else | |
166 | next_state = state; | |
167 | end | |
168 | ||
169 | CPU_ARB: | |
170 | begin | |
171 | if (is_cpu_req) | |
172 | begin | |
173 | cpu_sched_sm = 1'b1; | |
174 | next_state = CPU_IDLE; | |
175 | end | |
176 | else if (fc_lookup_req) | |
177 | begin | |
178 | fwd_fc_sched_sm = 1'b1; | |
179 | next_state = FWD_IDLE; | |
180 | end | |
181 | else | |
182 | next_state = FWD_ARB; | |
183 | end | |
184 | ||
185 | CPU_IDLE: | |
186 | begin | |
187 | next_state = FWD_ARB; | |
188 | end | |
189 | ||
190 | default: next_state = FWD_ARB; | |
191 | ||
192 | endcase | |
193 | ||
194 | end | |
195 | ||
196 | assign fwd_sched_in = fwd_fc_sched_sm | fwd_no_fc_sched_sm; | |
197 | ||
198 | dffr #(2) state_reg (cclk, reset, next_state, state); | |
199 | dffr #(1) fwd_sched_reg (cclk, reset, fwd_sched_in, fwd_sched); | |
200 | dffr #(1) fwd_fc_sched_reg (cclk, reset, fwd_fc_sched_sm, fwd_fc_sched); | |
201 | dffr #(1) cpu_sched_reg (cclk, reset, cpu_sched_sm, cpu_sched); | |
202 | ||
203 | dffr #(1) fwd_sched_1_reg (cclk, reset, fwd_sched, fwd_sched_1); | |
204 | dffr #(1) fwd_sched_2_reg (cclk, reset, fwd_sched_1, fwd_sched_2); | |
205 | dffr #(1) fc_fifo_ren_reg (cclk, reset, fc_fifo_ren_in, fc_fifo_ren); | |
206 | ||
207 | assign fc_fifo_ren_in = fwd_sched | fwd_sched_1 | fwd_sched_2; | |
208 | ||
209 | ||
210 | /*********************************************************************/ | |
211 | //allocate load balance, cpu bandwidth | |
212 | /*********************************************************************/ | |
213 | assign fwd_reqs_served = (fwd_sched_cnt == fcram_lookup_ratio); | |
214 | assign fwd_sched_cnt_en = fwd_fc_sched_sm | cpu_sched_sm; | |
215 | assign fwd_sched_cnt_in = (cpu_sched_sm | fwd_reqs_served & fwd_fc_sched_sm) ? 4'b0000 : (fwd_sched_cnt + 4'd1); | |
216 | ||
217 | dffre #(4) fwd_sched_cnt_reg (cclk, reset, fwd_sched_cnt_en, fwd_sched_cnt_in, fwd_sched_cnt); | |
218 | ||
219 | ||
220 | /**********************/ | |
221 | //CPU Request | |
222 | /**********************/ | |
223 | assign cpu_req_pulse = cpu_fcram_req_sync & !cpu_fcram_req_sync_d; | |
224 | assign is_cpu_req_en = cpu_req_pulse | cpu_sched; | |
225 | assign is_cpu_req_in = cpu_req_pulse ? 1'b1 : 1'b0; | |
226 | ||
227 | dffr #(1) cpu_req_dly_reg (cclk, reset, cpu_fcram_req_sync, cpu_fcram_req_sync_d); | |
228 | dffre #(1) is_cpu_req_reg (cclk, reset, is_cpu_req_en, is_cpu_req_in, is_cpu_req); | |
229 | ||
230 | assign do_srch_cycle_en = fwd_fc_sched | srch_burst_done; | |
231 | assign do_srch_cycle_in = fwd_fc_sched ? 1'b1 : 1'b0; | |
232 | assign do_cpu_cycle_en = cpu_sched | cpu_burst_done_sm; | |
233 | assign do_cpu_cycle_in = cpu_sched ? 1'b1 : 1'b0; | |
234 | ||
235 | dffre #(1) do_srch_cycle_reg (cclk, reset, do_srch_cycle_en, do_srch_cycle_in, do_srch_cycle); | |
236 | dffre #(1) do_cpu_cycle_reg (cclk, reset, do_cpu_cycle_en, do_cpu_cycle_in, do_cpu_cycle); | |
237 | ||
238 | ||
239 | ||
240 | endmodule |