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[/] [test_project/] [trunk/] [rtl/] [verilog/] [components/] [or1200r2/] [or1200_rf.v] - Blame information for rev 45

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//////////////////////////////////////////////////////////////////////
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////                                                              ////
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////  OR1200's register file inside CPU                           ////
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////                                                              ////
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////  This file is part of the OpenRISC 1200 project              ////
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////  http://www.opencores.org/cores/or1k/                        ////
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////                                                              ////
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////  Description                                                 ////
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////  Instantiation of register file memories                     ////
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////                                                              ////
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////  To Do:                                                      ////
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////   - make it smaller and faster                               ////
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////                                                              ////
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////  Author(s):                                                  ////
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////      - Damjan Lampret, lampret@opencores.org                 ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
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////                                                              ////
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//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
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////                                                              ////
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//// This source file may be used and distributed without         ////
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//// restriction provided that this copyright statement is not    ////
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//// removed from the file and that any derivative work contains  ////
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//// the original copyright notice and the associated disclaimer. ////
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////                                                              ////
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//// This source file is free software; you can redistribute it   ////
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//// and/or modify it under the terms of the GNU Lesser General   ////
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//// Public License as published by the Free Software Foundation; ////
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//// either version 2.1 of the License, or (at your option) any   ////
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//// later version.                                               ////
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////                                                              ////
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//// This source is distributed in the hope that it will be       ////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
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//// PURPOSE.  See the GNU Lesser General Public License for more ////
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//// details.                                                     ////
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////                                                              ////
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//// You should have received a copy of the GNU Lesser General    ////
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//// Public License along with this source; if not, download it   ////
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//// from http://www.opencores.org/lgpl.shtml                     ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
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//
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// CVS Revision History
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//
46
// $Log: or1200_rf.v,v $
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// Revision 1.3  2003/04/07 01:21:56  lampret
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// RFRAM type always need to be defined.
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//
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// Revision 1.2  2002/06/08 16:19:09  lampret
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// Added generic flip-flop based memory macro instantiation.
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//
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// Revision 1.1  2002/01/03 08:16:15  lampret
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// New prefixes for RTL files, prefixed module names. Updated cache controllers and MMUs.
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//
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// Revision 1.13  2001/11/20 18:46:15  simons
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// Break point bug fixed
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//
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// Revision 1.12  2001/11/13 10:02:21  lampret
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// Added 'setpc'. Renamed some signals (except_flushpipe into flushpipe etc)
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//
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// Revision 1.11  2001/11/12 01:45:40  lampret
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// Moved flag bit into SR. Changed RF enable from constant enable to dynamic enable for read ports.
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//
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// Revision 1.10  2001/11/10 03:43:57  lampret
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// Fixed exceptions.
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//
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// Revision 1.9  2001/10/21 17:57:16  lampret
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// 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.
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//
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// Revision 1.8  2001/10/14 13:12:10  lampret
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// MP3 version.
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//
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// Revision 1.1.1.1  2001/10/06 10:18:36  igorm
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// no message
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//
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// Revision 1.3  2001/08/09 13:39:33  lampret
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// Major clean-up.
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//
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// Revision 1.2  2001/07/22 03:31:54  lampret
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// Fixed RAM's oen bug. Cache bypass under development.
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//
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// Revision 1.1  2001/07/20 00:46:21  lampret
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// Development version of RTL. Libraries are missing.
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//
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//
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88
// synopsys translate_off
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`include "timescale.v"
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// synopsys translate_on
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`include "or1200_defines.v"
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93
module or1200_rf(
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        // Clock and reset
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        clk, rst,
96
 
97
        // Write i/f
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        cy_we_i, cy_we_o, supv, wb_freeze, addrw, dataw, we, flushpipe,
99
 
100
        // Read i/f
101
        id_freeze, addra, addrb, dataa, datab, rda, rdb,
102
 
103
        // Debug
104
        spr_cs, spr_write, spr_addr, spr_dat_i, spr_dat_o
105
);
106
 
107
parameter dw = `OR1200_OPERAND_WIDTH;
108
parameter aw = `OR1200_REGFILE_ADDR_WIDTH;
109
 
110
//
111
// I/O
112
//
113
 
114
//
115
// Clock and reset
116
//
117
input                           clk;
118
input                           rst;
119
 
120
//
121
// Write i/f
122
//
123
input                           cy_we_i;
124
output                          cy_we_o;
125
input                           supv;
126
input                           wb_freeze;
127
input   [aw-1:0]         addrw;
128
input   [dw-1:0]         dataw;
129
input                           we;
130
input                           flushpipe;
131
 
132
//
133
// Read i/f
134
//
135
input                           id_freeze;
136
input   [aw-1:0]         addra;
137
input   [aw-1:0]         addrb;
138
output  [dw-1:0]         dataa;
139
output  [dw-1:0]         datab;
140
input                           rda;
141
input                           rdb;
142
 
143
//
144
// SPR access for debugging purposes
145
//
146
input                           spr_cs;
147
input                           spr_write;
148
input   [31:0]                   spr_addr;
149
input   [31:0]                   spr_dat_i;
150
output  [31:0]                   spr_dat_o;
151
 
152
//
153
// Internal wires and regs
154
//
155
wire    [dw-1:0]         from_rfa;
156
wire    [dw-1:0]         from_rfb;
157
reg     [dw:0]                   dataa_saved;
158
reg     [dw:0]                   datab_saved;
159
wire    [aw-1:0]         rf_addra;
160
wire    [aw-1:0]         rf_addrw;
161
wire    [dw-1:0]         rf_dataw;
162
wire                            rf_we;
163
wire                            spr_valid;
164
wire                            rf_ena;
165
wire                            rf_enb;
166
reg                             rf_we_allow;
167
 
168
//
169
// SPR access is valid when spr_cs is asserted and
170
// SPR address matches GPR addresses
171
//
172
assign spr_valid = spr_cs & (spr_addr[10:5] == `OR1200_SPR_RF);
173
 
174
//
175
// SPR data output is always from RF A
176
//
177
assign spr_dat_o = from_rfa;
178
 
179
//
180
// Operand A comes from RF or from saved A register
181
//
182
assign dataa = (dataa_saved[32]) ? dataa_saved[31:0] : from_rfa;
183
 
184
//
185
// Operand B comes from RF or from saved B register
186
//
187
assign datab = (datab_saved[32]) ? datab_saved[31:0] : from_rfb;
188
 
189
//
190
// RF A read address is either from SPRS or normal from CPU control
191
//
192
assign rf_addra = (spr_valid & !spr_write) ? spr_addr[4:0] : addra;
193
 
194
//
195
// RF write address is either from SPRS or normal from CPU control
196
//
197
assign rf_addrw = (spr_valid & spr_write) ? spr_addr[4:0] : addrw;
198
 
199
//
200
// RF write data is either from SPRS or normal from CPU datapath
201
//
202
assign rf_dataw = (spr_valid & spr_write) ? spr_dat_i : dataw;
203
 
204
//
205
// RF write enable is either from SPRS or normal from CPU control
206
//
207
always @(posedge rst or posedge clk)
208
        if (rst)
209
                rf_we_allow <= #1 1'b1;
210
        else if (~wb_freeze)
211
                rf_we_allow <= #1 ~flushpipe;
212
 
213
assign rf_we = ((spr_valid & spr_write) | (we & ~wb_freeze)) & rf_we_allow & (supv | (|rf_addrw));
214
assign cy_we_o = cy_we_i && rf_we ;
215
 
216
//
217
// CS RF A asserted when instruction reads operand A and ID stage
218
// is not stalled
219
//
220
assign rf_ena = rda & ~id_freeze | spr_valid;   // probably works with fixed binutils
221
// assign rf_ena = 1'b1;                        // does not work with single-stepping
222
//assign rf_ena = ~id_freeze | spr_valid;       // works with broken binutils 
223
 
224
//
225
// CS RF B asserted when instruction reads operand B and ID stage
226
// is not stalled
227
//
228
assign rf_enb = rdb & ~id_freeze | spr_valid;
229
// assign rf_enb = 1'b1;
230
//assign rf_enb = ~id_freeze | spr_valid;       // works with broken binutils 
231
 
232
//
233
// Stores operand from RF_A into temp reg when pipeline is frozen
234
//
235
always @(posedge clk or posedge rst)
236
        if (rst) begin
237
                dataa_saved <= #1 33'b0;
238
        end
239
        else if (id_freeze & !dataa_saved[32]) begin
240
                dataa_saved <= #1 {1'b1, from_rfa};
241
        end
242
        else if (!id_freeze)
243
                dataa_saved <= #1 33'b0;
244
 
245
//
246
// Stores operand from RF_B into temp reg when pipeline is frozen
247
//
248
always @(posedge clk or posedge rst)
249
        if (rst) begin
250
                datab_saved <= #1 33'b0;
251
        end
252
        else if (id_freeze & !datab_saved[32]) begin
253
                datab_saved <= #1 {1'b1, from_rfb};
254
        end
255
        else if (!id_freeze)
256
                datab_saved <= #1 33'b0;
257
 
258
`ifdef OR1200_RFRAM_TWOPORT
259
 
260
//
261
// Instantiation of register file two-port RAM A
262
//
263
or1200_tpram_32x32 rf_a(
264
        // Port A
265
        .clk_a(clk),
266
        .rst_a(rst),
267
        .ce_a(rf_ena),
268
        .we_a(1'b0),
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        .oe_a(1'b1),
270
        .addr_a(rf_addra),
271
        .di_a(32'h0000_0000),
272
        .do_a(from_rfa),
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274
        // Port B
275
        .clk_b(clk),
276
        .rst_b(rst),
277
        .ce_b(rf_we),
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        .we_b(rf_we),
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        .oe_b(1'b0),
280
        .addr_b(rf_addrw),
281
        .di_b(rf_dataw),
282
        .do_b()
283
);
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285
//
286
// Instantiation of register file two-port RAM B
287
//
288
or1200_tpram_32x32 rf_b(
289
        // Port A
290
        .clk_a(clk),
291
        .rst_a(rst),
292
        .ce_a(rf_enb),
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        .we_a(1'b0),
294
        .oe_a(1'b1),
295
        .addr_a(addrb),
296
        .di_a(32'h0000_0000),
297
        .do_a(from_rfb),
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299
        // Port B
300
        .clk_b(clk),
301
        .rst_b(rst),
302
        .ce_b(rf_we),
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        .we_b(rf_we),
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        .oe_b(1'b0),
305
        .addr_b(rf_addrw),
306
        .di_b(rf_dataw),
307
        .do_b()
308
);
309
 
310
`else
311
 
312
`ifdef OR1200_RFRAM_DUALPORT
313
 
314
//
315
// Instantiation of register file two-port RAM A
316
//
317
   or1200_dpram #
318
     (
319
      .aw(5),
320
      .dw(32)
321
      )
322
   rf_a
323
     (
324
      // Port A
325
      .clk_a(clk),
326
      .ce_a(rf_ena),
327
      .addr_a(rf_addra),
328
      .do_a(from_rfa),
329
 
330
      // Port B
331
      .clk_b(clk),
332
      .ce_b(rf_we),
333
      .we_b(rf_we),
334
      .addr_b(rf_addrw),
335
      .di_b(rf_dataw)
336
      );
337
 
338
   //
339
   // Instantiation of register file two-port RAM B
340
   //
341
   or1200_dpram #
342
     (
343
      .aw(5),
344
      .dw(32)
345
      )
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   rf_b
347
     (
348
      // Port A
349
      .clk_a(clk),
350
      .ce_a(rf_enb),
351
      .addr_a(addrb),
352
      .do_a(from_rfb),
353
 
354
      // Port B
355
      .clk_b(clk),
356
      .ce_b(rf_we),
357
      .we_b(rf_we),
358
      .addr_b(rf_addrw),
359
      .di_b(rf_dataw)
360
      );
361
 
362
`else
363
 
364
`ifdef OR1200_RFRAM_GENERIC
365
 
366
//
367
// Instantiation of generic (flip-flop based) register file
368
//
369
or1200_rfram_generic rf_a(
370
        // Clock and reset
371
        .clk(clk),
372
        .rst(rst),
373
 
374
        // Port A
375
        .ce_a(rf_ena),
376
        .addr_a(rf_addra),
377
        .do_a(from_rfa),
378
 
379
        // Port B
380
        .ce_b(rf_enb),
381
        .addr_b(addrb),
382
        .do_b(from_rfb),
383
 
384
        // Port W
385
        .ce_w(rf_we),
386
        .we_w(rf_we),
387
        .addr_w(rf_addrw),
388
        .di_w(rf_dataw)
389
);
390
 
391
`else
392
 
393
//
394
// RFRAM type not specified
395
//
396
initial begin
397
        $display("Define RFRAM type.");
398
        $finish;
399
end
400
 
401
`endif
402
`endif
403
`endif
404
 
405
endmodule

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