OpenCores
URL https://opencores.org/ocsvn/or1k/or1k/trunk

Subversion Repositories or1k

[/] [or1k/] [trunk/] [orp/] [orp_soc/] [rtl/] [verilog/] [or1200.old/] [or1200_dc_fsm.v] - Blame information for rev 746

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

Line No. Rev Author Line
1 746 lampret
//////////////////////////////////////////////////////////////////////
2
////                                                              ////
3
////  OR1200's DC FSM                                             ////
4
////                                                              ////
5
////  This file is part of the OpenRISC 1200 project              ////
6
////  http://www.opencores.org/cores/or1k/                        ////
7
////                                                              ////
8
////  Description                                                 ////
9
////  Data cache state machine                                    ////
10
////                                                              ////
11
////  To Do:                                                      ////
12
////   - make it smaller and faster                               ////
13
////                                                              ////
14
////  Author(s):                                                  ////
15
////      - Damjan Lampret, lampret@opencores.org                 ////
16
////                                                              ////
17
//////////////////////////////////////////////////////////////////////
18
////                                                              ////
19
//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
20
////                                                              ////
21
//// This source file may be used and distributed without         ////
22
//// restriction provided that this copyright statement is not    ////
23
//// removed from the file and that any derivative work contains  ////
24
//// the original copyright notice and the associated disclaimer. ////
25
////                                                              ////
26
//// This source file is free software; you can redistribute it   ////
27
//// and/or modify it under the terms of the GNU Lesser General   ////
28
//// Public License as published by the Free Software Foundation; ////
29
//// either version 2.1 of the License, or (at your option) any   ////
30
//// later version.                                               ////
31
////                                                              ////
32
//// This source is distributed in the hope that it will be       ////
33
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
34
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
35
//// PURPOSE.  See the GNU Lesser General Public License for more ////
36
//// details.                                                     ////
37
////                                                              ////
38
//// You should have received a copy of the GNU Lesser General    ////
39
//// Public License along with this source; if not, download it   ////
40
//// from http://www.opencores.org/lgpl.shtml                     ////
41
////                                                              ////
42
//////////////////////////////////////////////////////////////////////
43
//
44
// CVS Revision History
45
//
46
// $Log: not supported by cvs2svn $
47
// Revision 1.5  2002/02/11 04:33:17  lampret
48
// Speed optimizations (removed duplicate _cyc_ and _stb_). Fixed D/IMMU cache-inhibit attr.
49
//
50
// Revision 1.4  2002/02/01 19:56:54  lampret
51
// Fixed combinational loops.
52
//
53
// Revision 1.3  2002/01/28 01:15:59  lampret
54
// Changed 'void' nop-ops instead of insn[0] to use insn[16]. Debug unit stalls the tick timer. Prepared new flag generation for add and and insns. Blocked DC/IC while they are turned off. Fixed I/D MMU SPRs layout except WAYs. TODO: smart IC invalidate, l.j 2 and TLB ways.
55
//
56
// Revision 1.2  2002/01/14 06:18:22  lampret
57
// Fixed mem2reg bug in FAST implementation. Updated debug unit to work with new genpc/if.
58
//
59
// Revision 1.1  2002/01/03 08:16:15  lampret
60
// New prefixes for RTL files, prefixed module names. Updated cache controllers and MMUs.
61
//
62
// Revision 1.9  2001/10/21 17:57:16  lampret
63
// Removed params from generic_XX.v. Added translate_off/on in sprs.v and id.v. Removed spr_addr from dc.v and ic.v. Fixed CR+LF.
64
//
65
// Revision 1.8  2001/10/19 23:28:46  lampret
66
// Fixed some synthesis warnings. Configured with caches and MMUs.
67
//
68
// Revision 1.7  2001/10/14 13:12:09  lampret
69
// MP3 version.
70
//
71
// Revision 1.1.1.1  2001/10/06 10:18:35  igorm
72
// no message
73
//
74
// Revision 1.2  2001/08/09 13:39:33  lampret
75
// Major clean-up.
76
//
77
// Revision 1.1  2001/07/20 00:46:03  lampret
78
// Development version of RTL. Libraries are missing.
79
//
80
//
81
 
82
// synopsys translate_off
83
`include "timescale.v"
84
// synopsys translate_on
85
`include "or1200_defines.v"
86
 
87
`define OR1200_DCFSM_IDLE       3'd0
88
`define OR1200_DCFSM_CLOAD      3'd1
89
`define OR1200_DCFSM_LREFILL3   3'd2
90
`define OR1200_DCFSM_CSTORE     3'd3
91
`define OR1200_DCFSM_SREFILL4   3'd4
92
`define OR1200_DCFSM_ILOAD      3'd5
93
`define OR1200_DCFSM_ISTORE     3'd6
94
 
95
//
96
// Data cache FSM for cache line of 16 bytes (4x singleword)
97
//
98
 
99
module or1200_dc_fsm(
100
        // Clock and reset
101
        clk, rst,
102
 
103
        // Internal i/f to top level DC
104
        dc_en, dcdmmu_cycstb_i, dcdmmu_ci_i, dcpu_we_i, dcpu_sel_i,
105
        tagcomp_miss, biudata_valid, biudata_error, start_addr, saved_addr,
106
        dcram_we, biu_read, biu_write, first_hit_ack, first_miss_ack, first_miss_err,
107
        burst, tag_we, dc_addr
108
);
109
 
110
//
111
// I/O
112
//
113
input                           clk;
114
input                           rst;
115
input                           dc_en;
116
input                           dcdmmu_cycstb_i;
117
input                           dcdmmu_ci_i;
118
input                           dcpu_we_i;
119
input   [3:0]                    dcpu_sel_i;
120
input                           tagcomp_miss;
121
input                           biudata_valid;
122
input                           biudata_error;
123
input   [31:0]                   start_addr;
124
output  [31:0]                   saved_addr;
125
output  [3:0]                    dcram_we;
126
output                          biu_read;
127
output                          biu_write;
128
output                          first_hit_ack;
129
output                          first_miss_ack;
130
output                          first_miss_err;
131
output                          burst;
132
output                          tag_we;
133
output  [31:0]                   dc_addr;
134
 
135
//
136
// Internal wires and regs
137
//
138
reg     [31:0]                   saved_addr_r;
139
reg     [2:0]                    state;
140
reg     [2:0]                    cnt;
141
reg                             hitmiss_eval;
142
reg                             store;
143
reg                             load;
144
reg                             cache_inhibit;
145
wire                            first_store_hit_ack;
146
 
147
//
148
// Generate of DCRAM write enables
149
//
150
assign dcram_we = {4{load & biudata_valid & !cache_inhibit}} | {4{first_store_hit_ack}} & dcpu_sel_i;
151
assign tag_we = biu_read & biudata_valid & !cache_inhibit;
152
 
153
//
154
// BIU read and write
155
//
156
assign biu_read = (hitmiss_eval & tagcomp_miss) | (!hitmiss_eval & load);
157
assign biu_write = store;
158
 
159
assign dc_addr = (biu_read | biu_write) & !hitmiss_eval ? saved_addr : start_addr;
160
assign saved_addr = saved_addr_r;
161
 
162
//
163
// Assert for cache hit first word ready
164
// Assert for store cache hit first word ready
165
// Assert for cache miss first word stored/loaded OK
166
// Assert for cache miss first word stored/loaded with an error
167
//
168
assign first_hit_ack = (state == `OR1200_DCFSM_CLOAD) & !tagcomp_miss & !cache_inhibit & !dcdmmu_ci_i | first_store_hit_ack;
169
assign first_store_hit_ack = (state == `OR1200_DCFSM_CSTORE) & !tagcomp_miss & biudata_valid & !cache_inhibit & !dcdmmu_ci_i;
170
assign first_miss_ack = ((state == `OR1200_DCFSM_CLOAD) | (state == `OR1200_DCFSM_CSTORE)) & biudata_valid;
171
assign first_miss_err = ((state == `OR1200_DCFSM_CLOAD) | (state == `OR1200_DCFSM_CSTORE)) & biudata_error;
172
 
173
//
174
// Assert burst when doing reload of complete cache line
175
//
176
assign burst = (state == `OR1200_DCFSM_CLOAD) & tagcomp_miss & !cache_inhibit
177
                | (state == `OR1200_DCFSM_LREFILL3)
178
`ifdef OR1200_DC_STORE_REFILL
179
                | (state == `OR1200_DCFSM_SREFILL4)
180
`endif
181
                ;
182
 
183
//
184
// Main DC FSM
185
//
186
always @(posedge clk or posedge rst) begin
187
        if (rst) begin
188
                state <= #1 `OR1200_DCFSM_IDLE;
189
                saved_addr_r <= #1 32'b0;
190
                hitmiss_eval <= #1 1'b0;
191
                store <= #1 1'b0;
192
                load <= #1 1'b0;
193
                cnt <= #1 3'b000;
194
                cache_inhibit <= #1 1'b0;
195
        end
196
        else
197
        case (state)    // synopsys parallel_case
198
                `OR1200_DCFSM_IDLE :
199
                        if (dc_en & dcdmmu_cycstb_i & dcpu_we_i) begin  // store
200
                                state <= #1 `OR1200_DCFSM_CSTORE;
201
                                saved_addr_r <= #1 start_addr;
202
                                hitmiss_eval <= #1 1'b1;
203
                                store <= #1 1'b1;
204
                                load <= #1 1'b0;
205
                                cache_inhibit <= #1 1'b0;
206
                        end
207
                        else if (dc_en & dcdmmu_cycstb_i) begin         // load
208
                                state <= #1 `OR1200_DCFSM_CLOAD;
209
                                saved_addr_r <= #1 start_addr;
210
                                hitmiss_eval <= #1 1'b1;
211
                                store <= #1 1'b0;
212
                                load <= #1 1'b1;
213
                                cache_inhibit <= #1 1'b0;
214
                        end
215
                        else begin                                                      // idle
216
                                state <= #1 `OR1200_DCFSM_IDLE;
217
                                hitmiss_eval <= #1 1'b0;
218
                                store <= #1 1'b0;
219
                                load <= #1 1'b0;
220
                                cache_inhibit <= #1 1'b0;
221
                        end
222
                `OR1200_DCFSM_CLOAD: begin              // load
223
                        if (dcdmmu_cycstb_i & dcdmmu_ci_i)
224
                                cache_inhibit <= #1 1'b1;
225
                        if (hitmiss_eval)
226
                                saved_addr_r[31:13] <= #1 start_addr[31:13];
227
                        if (!dc_en)
228
                                state <= #1 `OR1200_DCFSM_IDLE;
229
                        else if (hitmiss_eval & !dcdmmu_cycstb_i) begin // load aborted (usually caused by DMMU)
230
                                state <= #1 `OR1200_DCFSM_IDLE;
231
                                hitmiss_eval <= #1 1'b0;
232
                                load <= #1 1'b0;
233
                                cache_inhibit <= #1 1'b0;
234
                        end
235
                        else if (biudata_error) begin                   // load terminated with an error
236
                                state <= #1 `OR1200_DCFSM_IDLE;
237
                                hitmiss_eval <= #1 1'b0;
238
                                load <= #1 1'b0;
239
                                cache_inhibit <= #1 1'b0;
240
                        end
241
                        else if ((cache_inhibit | dcdmmu_ci_i) & biudata_valid) begin   // load from cache-inhibited area
242
                                state <= #1 `OR1200_DCFSM_IDLE;
243
                                hitmiss_eval <= #1 1'b0;
244
                                load <= #1 1'b0;
245
                                cache_inhibit <= #1 1'b0;
246
                        end
247
                        else if (tagcomp_miss & biudata_valid) begin    // load missed, finish current external load and refill
248
                                state <= #1 `OR1200_DCFSM_LREFILL3;
249
                                saved_addr_r[3:2] <= #1 saved_addr_r[3:2] + 'd1;
250
                                hitmiss_eval <= #1 1'b0;
251
                                cnt <= #1 `OR1200_DCLS-2;
252
                                cache_inhibit <= #1 1'b0;
253
                        end
254
                        else if (!tagcomp_miss & !dcdmmu_ci_i) begin    // load hit, finish immediately
255
                                state <= #1 `OR1200_DCFSM_IDLE;
256
                                hitmiss_eval <= #1 1'b0;
257
                                load <= #1 1'b0;
258
                                cache_inhibit <= #1 1'b0;
259
                        end
260
                        else                                            // load in-progress
261
                                hitmiss_eval <= #1 1'b0;
262
                end
263
                `OR1200_DCFSM_LREFILL3 : begin
264
                        if (!dc_en)
265
                                state <= #1 `OR1200_DCFSM_IDLE;
266
                        else if (biudata_valid && (|cnt)) begin         // refill ack, more loads to come
267
                                cnt <= #1 cnt - 'd1;
268
                                saved_addr_r[3:2] <= #1 saved_addr_r[3:2] + 'd1;
269
                        end
270
                        else if (biudata_valid) begin                   // last load of line refill
271
                                state <= #1 `OR1200_DCFSM_IDLE;
272
                                load <= #1 1'b0;
273
                        end
274
                end
275
                `OR1200_DCFSM_CSTORE: begin             // store
276
                        if (dcdmmu_cycstb_i & dcdmmu_ci_i)
277
                                cache_inhibit <= #1 1'b1;
278
                        if (hitmiss_eval)
279
                                saved_addr_r[31:13] <= #1 start_addr[31:13];
280
                        if (!dc_en)
281
                                state <= #1 `OR1200_DCFSM_IDLE;
282
                        else if (hitmiss_eval & !dcdmmu_cycstb_i) begin // store aborted (usually caused by DMMU)
283
                                state <= #1 `OR1200_DCFSM_IDLE;
284
                                hitmiss_eval <= #1 1'b0;
285
                                store <= #1 1'b0;
286
                                cache_inhibit <= #1 1'b0;
287
                        end
288
                        else if (biudata_error) begin                   // store terminated with an error
289
                                state <= #1 `OR1200_DCFSM_IDLE;
290
                                hitmiss_eval <= #1 1'b0;
291
                                store <= #1 1'b0;
292
                                cache_inhibit <= #1 1'b0;
293
                        end
294
                        else if ((cache_inhibit | dcdmmu_ci_i) & biudata_valid) begin   // store to cache-inhibited area
295
                                state <= #1 `OR1200_DCFSM_IDLE;
296
                                hitmiss_eval <= #1 1'b0;
297
                                store <= #1 1'b0;
298
                                cache_inhibit <= #1 1'b0;
299
                        end
300
`ifdef OR1200_DC_STORE_REFILL
301
                        else if (tagcomp_miss & biudata_valid) begin    // store missed, finish write-through and do load refill
302
                                state <= #1 `OR1200_DCFSM_SREFILL4;
303
                                hitmiss_eval <= #1 1'b0;
304
                                store <= #1 1'b0;
305
                                load <= #1 1'b1;
306
                                cnt <= #1 `OR1200_DCLS-1;
307
                                cache_inhibit <= #1 1'b0;
308
                        end
309
`endif
310
                        else if (biudata_valid) begin                   // store hit, finish write-through
311
                                state <= #1 `OR1200_DCFSM_IDLE;
312
                                hitmiss_eval <= #1 1'b0;
313
                                store <= #1 1'b0;
314
                                cache_inhibit <= #1 1'b0;
315
                        end
316
                        else                                            // store write-through in-progress
317
                                hitmiss_eval <= #1 1'b0;
318
                        end
319
`ifdef OR1200_DC_STORE_REFILL
320
                `OR1200_DCFSM_SREFILL4 : begin
321
                        if (!dc_en)
322
                                state <= #1 `OR1200_DCFSM_IDLE;
323
                        else if (biudata_valid && (|cnt)) begin         // refill ack, more loads to come
324
                                cnt <= #1 cnt - 'd1;
325
                                saved_addr_r[3:2] <= #1 saved_addr_r[3:2] + 'd1;
326
                        end
327
                        else if (biudata_valid) begin                   // last load of line refill
328
                                state <= #1 `OR1200_DCFSM_IDLE;
329
                                load <= #1 1'b0;
330
                        end
331
                end
332
`endif
333
                default:
334
                        state <= #1 `OR1200_DCFSM_IDLE;
335
        endcase
336
end
337
 
338
endmodule

powered by: WebSVN 2.1.0

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