OpenCores
URL https://opencores.org/ocsvn/rtf65002/rtf65002/trunk

Subversion Repositories rtf65002

[/] [rtf65002/] [trunk/] [rtl/] [verilog/] [decode.v] - Blame information for rev 23

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

Line No. Rev Author Line
1 20 robfinch 
// ============================================================================
2 
//        __
3 
//   \\__/ o\    (C) 2013  Robert Finch, Stratford
4 
//    \  __ /    All rights reserved.
5 
//     \/_//     robfinch<remove>@opencores.org
6 
//       ||
7 
//
8 
// This source file is free software: you can redistribute it and/or modify
9 
// it under the terms of the GNU Lesser General Public License as published
10 
// by the Free Software Foundation, either version 3 of the License, or
11 
// (at your option) any later version.
12 
//
13 
// This source file 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, see <http://www.gnu.org/licenses/>.
20 
//
21 
// ============================================================================
22 
//
23 
DECODE:
24 
        begin
25 
                first_ifetch <= `TRUE;
26 
                Rt <= 4'h0;             // Default
27 
                state <= IFETCH;
28 
                case(ir[7:0])
29 
                `STP:   begin clk_en <= 1'b0; pc <= pc + 32'd1; end
30 
                `NOP:   begin pc <= pc + 32'd1; end
31 
                `CLC:   begin cf <= 1'b0; pc <= pc + 32'd1; end
32 
                `SEC:   begin cf <= 1'b1; pc <= pc + 32'd1; end
33 
                `CLV:   begin vf <= 1'b0; pc <= pc + 32'd1; end
34 
                `CLI:   begin im <= 1'b0; pc <= pc + 32'd1; end
35 
                `CLD:   begin df <= 1'b0; pc <= pc + 32'd1; end
36 
                `SED:   begin df <= 1'b1; pc <= pc + 32'd1; end
37 
                `SEI:   begin im <= 1'b1; pc <= pc + 32'd1; end
38 
                `WAI:   begin wai <= 1'b1; pc <= pc + 32'd1; end
39 
                `EMM:   begin em <= 1'b1; pc <= pc + 32'd1; end
40 
                `DEX:   begin res <= x - 32'd1; pc <= pc + 32'd1; end
41 
                `INX:   begin res <= x + 32'd1; pc <= pc + 32'd1; end
42 
                `DEY:   begin res <= y - 32'd1; pc <= pc + 32'd1; end
43 
                `INY:   begin res <= y + 32'd1; pc <= pc + 32'd1; end
44 
                `DEA:   begin res <= acc - 32'd1; pc <= pc + 32'd1; end
45 
                `INA:   begin res <= acc + 32'd1; pc <= pc + 32'd1; end
46 23 robfinch 
                `TSX,`TSA:      begin res <= isp; pc <= pc + 32'd1; end
47 20 robfinch 
                `TXS,`TXA,`TXY: begin res <= x; pc <= pc + 32'd1; end
48 
                `TAX,`TAY,`TAS: begin res <= acc; pc <= pc + 32'd1; end
49 
                `TYA,`TYX:      begin res <= y; pc <= pc + 32'd1; end
50 
                `TRS:           begin
51 
                                                res <= rfoa; pc <= pc + 32'd2; end
52 
                `TSR:           begin
53 
                                                Rt <= ir[15:12];
54 
                                                case(ir[11:8])
55 
                                                4'h0:   res <= {write_allocate,dcacheOn,icacheOn};
56 
                                                4'h1:   res <= dp;
57 
                                                4'h2:   res <= prod[31:0];
58 
                                                4'h3:   res <= prod[63:32];
59 
                                                4'h4:   res <= tick;
60 
                                                4'h5:   begin res <= lfsr; lfsr <= {lfsr[30:0],lfsr_fb}; end
61 
                                                4'h6:   res <= dp8;
62 
                                                4'h7:   res <= abs8;
63 
                                                4'h8:   res <= {vbr[31:1],nmoi};
64 23 robfinch 
                                                4'h9:   res <= derr_address;
65 20 robfinch 
                                                4'hE:   res <= {spage[31:8],sp};
66 
                                                4'hF:   res <= isp;
67 
                                                endcase
68 
                                                pc <= pc + 32'd2;
69 
                                        end
70 
                `ASL_ACC:       begin res <= {acc,1'b0}; pc <= pc + 32'd1; end
71 
                `ROL_ACC:       begin res <= {acc,cf}; pc <= pc + 32'd1; end
72 
                `LSR_ACC:       begin res <= {acc[0],1'b0,acc[31:1]}; pc <= pc + 32'd1; end
73 
                `ROR_ACC:       begin res <= {acc[0],cf,acc[31:1]}; pc <= pc + 32'd1; end
74 
 
75 
                `RR:
76 
                        begin
77 
                                state <= IFETCH;
78 
                                case(ir[23:20])
79 21 robfinch 
                                `ADD_RR:        begin res <= rfoa + rfob + {31'b0,df&cf}; a <= rfoa; b <= rfob; end
80 
                                `SUB_RR:        begin res <= rfoa - rfob - {31'b0,df&~cf&|ir[19:16]}; a <= rfoa; b <= rfob; end
81 20 robfinch 
                                `AND_RR:        begin res <= rfoa & rfob; a <= rfoa; b <= rfob; end     // for bit flags
82 
                                `OR_RR:         begin res <= rfoa | rfob; a <= rfoa; b <= rfob; end
83 
                                `EOR_RR:        begin res <= rfoa ^ rfob; a <= rfoa; b <= rfob; end
84 
                                `MUL_RR:        begin state <= MULDIV1; end
85 
                                `MULS_RR:       begin state <= MULDIV1; end
86 
                                `DIV_RR:        begin state <= MULDIV1; end
87 
                                `DIVS_RR:       begin state <= MULDIV1; end
88 
                                `MOD_RR:        begin state <= MULDIV1; end
89 
                                `MODS_RR:       begin state <= MULDIV1; end
90 
                                `ASL_RRR:       begin a <= rfoa; b <= rfob; state <= CALC; end
91 
                                `LSR_RRR:       begin a <= rfoa; b <= rfob; state <= CALC; end
92 
                                endcase
93 
                                Rt <= ir[19:16];
94 
                                pc <= pc + 32'd3;
95 
                        end
96 
                `LD_RR:         begin res <= rfoa; Rt <= ir[15:12]; pc <= pc + 32'd2; end
97 
                `ASL_RR:        begin res <= {rfoa,1'b0}; pc <= pc + 32'd2; Rt <= ir[15:12]; end
98 
                `ROL_RR:        begin res <= {rfoa,cf}; pc <= pc + 32'd2; Rt <= ir[15:12]; end
99 
                `LSR_RR:        begin res <= {rfoa[0],1'b0,rfoa[31:1]}; pc <= pc + 32'd2; Rt <= ir[15:12]; end
100 
                `ROR_RR:        begin res <= {rfoa[0],cf,rfoa[31:1]}; pc <= pc + 32'd2; Rt <= ir[15:12]; end
101 
                `DEC_RR:        begin res <= rfoa - 32'd1; pc <= pc + 32'd2; Rt <= ir[15:12]; end
102 
                `INC_RR:        begin res <= rfoa + 32'd1; pc <= pc + 32'd2; Rt <= ir[15:12]; end
103 
 
104 21 robfinch 
                `ADD_IMM8:      begin res <= rfoa + {{24{ir[23]}},ir[23:16]} + {31'b0,df&cf}; Rt <= ir[15:12]; pc <= pc + 32'd3; a <= rfoa; b <= {{24{ir[23]}},ir[23:16]}; end
105 
                `SUB_IMM8:      begin res <= rfoa - {{24{ir[23]}},ir[23:16]} - {31'b0,df&~cf&|ir[15:12]}; Rt <= ir[15:12]; pc <= pc + 32'd3; a <= rfoa; b <= {{24{ir[23]}},ir[23:16]}; end
106 20 robfinch 
                `OR_IMM8:       begin res <= rfoa | {{24{ir[23]}},ir[23:16]}; Rt <= ir[15:12]; pc <= pc + 32'd3; b <= {{24{ir[23]}},ir[23:16]}; end
107 
                `AND_IMM8:      begin res <= rfoa & {{24{ir[23]}},ir[23:16]}; Rt <= ir[15:12]; pc <= pc + 32'd3; b <= {{24{ir[23]}},ir[23:16]}; end
108 
                `EOR_IMM8:      begin res <= rfoa ^ {{24{ir[23]}},ir[23:16]}; Rt <= ir[15:12]; pc <= pc + 32'd3; b <= {{24{ir[23]}},ir[23:16]}; end
109 
                `CMP_IMM8:      begin res <= acc - {{24{ir[15]}},ir[15:8]}; Rt <= 4'h0; pc <= pc + 32'd2; b <= {{24{ir[15]}},ir[15:8]}; end
110 
                `ASL_IMM8:      begin a <= rfoa; b <= ir[20:16]; Rt <= ir[15:12]; pc <= pc + 32'd3; state <= CALC; end
111 
                `LSR_IMM8:      begin a <= rfoa; b <= ir[20:16]; Rt <= ir[15:12]; pc <= pc + 32'd3; state <= CALC; end
112 
 
113 21 robfinch 
                `ADD_IMM16:     begin res <= rfoa + {{16{ir[31]}},ir[31:16]} + {31'b0,df&cf}; Rt <= ir[15:12]; pc <= pc + 32'd4; a <= rfoa; b <= {{16{ir[31]}},ir[31:16]}; end
114 
                `SUB_IMM16:     begin res <= rfoa - {{16{ir[31]}},ir[31:16]} - {31'b0,df&~cf&|ir[15:12]}; Rt <= ir[15:12]; pc <= pc + 32'd4; a <= rfoa; b <= {{16{ir[31]}},ir[31:16]}; end
115 20 robfinch 
                `OR_IMM16:      begin res <= rfoa | {{16{ir[31]}},ir[31:16]}; Rt <= ir[15:12]; pc <= pc + 32'd4; b <= {{16{ir[31]}},ir[31:16]}; end
116 
                `AND_IMM16:     begin res <= rfoa & {{16{ir[31]}},ir[31:16]}; Rt <= ir[15:12]; pc <= pc + 32'd4; b <= {{16{ir[31]}},ir[31:16]}; end
117 
                `EOR_IMM16:     begin res <= rfoa ^ {{16{ir[31]}},ir[31:16]}; Rt <= ir[15:12]; pc <= pc + 32'd4; b <= {{16{ir[31]}},ir[31:16]}; end
118 
 
119 21 robfinch 
                `ADD_IMM32:     begin res <= rfoa + ir[47:16]; Rt <= ir[15:12] + {31'b0,df&cf}; pc <= pc + 32'd6; a <= rfoa; b <= ir[47:16]; end
120 
                `SUB_IMM32:     begin res <= rfoa - ir[47:16]; Rt <= ir[15:12] - {31'b0,df&~cf&|ir[15:12]}; pc <= pc + 32'd6; a <= rfoa; b <= ir[47:16]; end
121 20 robfinch 
                `OR_IMM32:      begin res <= rfoa | ir[47:16]; Rt <= ir[15:12]; pc <= pc + 32'd6; b <= ir[47:16]; end
122 
                `AND_IMM32:     begin res <= rfoa & ir[47:16]; Rt <= ir[15:12]; pc <= pc + 32'd6; b <= ir[47:16]; end
123 
                `EOR_IMM32:     begin res <= rfoa ^ ir[47:16]; Rt <= ir[15:12]; pc <= pc + 32'd6; b <= ir[47:16]; end
124 
 
125 
                `LDX_IMM32,`LDY_IMM32,`LDA_IMM32:       begin res <= ir[39:8]; pc <= pc + 32'd5; end
126 
                `LDX_IMM16,`LDA_IMM16:  begin res <= {{16{ir[23]}},ir[23:8]}; pc <= pc + 32'd3; end
127 
                `LDX_IMM8,`LDA_IMM8: begin res <= {{24{ir[15]}},ir[15:8]}; pc <= pc + 32'd2; end
128 
 
129 23 robfinch 
                `SUB_SP:        begin res <= isp - {{24{ir[15]}},ir[15:8]}; pc <= pc + 32'd2; end
130 
 
131 20 robfinch 
                `LDX_ZPX,`LDY_ZPX:
132 
                        begin
133 
                                radr <= zpx32xy_address;
134 
                                pc <= pc + 32'd3;
135 21 robfinch 
                                load_what <= `WORD_311;
136 
                                state <= LOAD_MAC1;
137 20 robfinch 
                        end
138 
                `ORB_ZPX:
139 
                        begin
140 
                                a <= rfoa;
141 
                                Rt <= ir[19:16];
142 
                                radr <= zpx32_address[31:2];
143 
                                radr2LSB <= zpx32_address[1:0];
144 
                                pc <= pc + 32'd4;
145 21 robfinch 
                                load_what <= `WORD_310;
146 
                                state <= LOAD_MAC1;
147 20 robfinch 
                        end
148 
                `LDX_ABS,`LDY_ABS:
149 
                        begin
150 
                                radr <= ir[39:8];
151 
                                pc <= pc + 32'd5;
152 21 robfinch 
                                load_what <= `WORD_311;
153 
                                state <= LOAD_MAC1;
154 20 robfinch 
                        end
155 
                `ORB_ABS:
156 
                        begin
157 
                                a <= rfoa;
158 
                                Rt <= ir[15:12];
159 
                                radr <= ir[47:18];
160 
                                radr2LSB <= ir[17:16];
161 
                                pc <= pc + 32'd6;
162 21 robfinch 
                                load_what <= `WORD_310;
163 
                                state <= LOAD_MAC1;
164 20 robfinch 
                        end
165 
                `LDX_ABSY,`LDY_ABSX:
166 
                        begin
167 
                                radr <= absx32xy_address;
168 
                                pc <= pc + 32'd6;
169 21 robfinch 
                                load_what <= `WORD_311;
170 
                                state <= LOAD_MAC1;
171 20 robfinch 
                        end
172 
                `ORB_ABSX:
173 
                        begin
174 
                                a <= rfoa;
175 
                                Rt <= ir[19:16];
176 
                                radr <= absx32_address[31:2];
177 
                                radr2LSB <= absx32_address[1:0];
178 
                                pc <= pc + 32'd7;
179 21 robfinch 
                                load_what <= `WORD_310;
180 
                                state <= LOAD_MAC1;
181 20 robfinch 
                        end
182 
                `ST_ZPX:
183 
                        begin
184 
                                wadr <= zpx32_address;
185 
                                wdat <= rfoa;
186 
                                pc <= pc + 32'd4;
187 
                                state <= STORE1;
188 
                        end
189 
                `STB_ZPX:
190 
                        begin
191 
                                wadr <= zpx32_address[31:2];
192 
                                wadr2LSB <= zpx32_address[1:0];
193 
                                pc <= pc + 32'd4;
194 
                                state <= STORE1;
195 
                        end
196 23 robfinch 
                `ST_DSP:
197 
                        begin
198 
                                wadr <= {{24{ir[23]}},ir[23:16]} + isp;
199 
                                wdat <= rfoa;
200 
                                pc <= pc + 32'd3;
201 
                                state <= STORE1;
202 
                        end
203 20 robfinch 
                `ST_ABS:
204 
                        begin
205 
                                wadr <= ir[47:16];
206 
                                wdat <= rfoa;
207 
                                pc <= pc + 32'd6;
208 
                                state <= STORE1;
209 
                        end
210 
                `STB_ABS:
211 
                        begin
212 
                                wadr <= ir[47:18];
213 
                                wadr2LSB <= ir[17:16];
214 
                                wdat <= {4{rfoa[7:0]}};
215 
                                pc <= pc + 32'd6;
216 
                                state <= STORE1;
217 
                        end
218 
                `ST_ABSX:
219 
                        begin
220 
                                wadr <= absx32_address;
221 
                                wdat <= rfoa;
222 
                                pc <= pc + 32'd7;
223 
                                state <= STORE1;
224 
                        end
225 
                `STB_ABSX:
226 
                        begin
227 
                                wadr <= absx32_address[31:2];
228 
                                wadr2LSB <= absx32_address[1:0];
229 
                                wdat <= {4{rfoa[7:0]}};
230 
                                pc <= pc + 32'd7;
231 
                                state <= STORE1;
232 
                        end
233 
                `STX_ZPX:
234 
                        begin
235 
                                wadr <= dp + ir[23:12] + rfoa;
236 
                                wdat <= x;
237 
                                pc <= pc + 32'd3;
238 
                                state <= STORE1;
239 
                        end
240 
                `STX_ABS:
241 
                        begin
242 
                                wadr <= ir[39:8];
243 
                                wdat <= x;
244 
                                pc <= pc + 32'd5;
245 
                                state <= STORE1;
246 
                        end
247 
                `STY_ZPX:
248 
                        begin
249 
                                wadr <= dp + ir[23:12] + rfoa;
250 
                                wdat <= y;
251 
                                pc <= pc + 32'd3;
252 
                                state <= STORE1;
253 
                        end
254 
                `STY_ABS:
255 
                        begin
256 
                                wadr <= ir[39:8];
257 
                                wdat <= y;
258 
                                pc <= pc + 32'd5;
259 
                                state <= STORE1;
260 
                        end
261 
                `ADD_ZPX,`SUB_ZPX,`OR_ZPX,`AND_ZPX,`EOR_ZPX:
262 
                        begin
263 
                                a <= rfoa;
264 
                                Rt <= ir[19:16];
265 
                                radr <= zpx32_address;
266 
                                pc <= pc + 32'd4;
267 21 robfinch 
                                load_what <= `WORD_310;
268 
                                state <= LOAD_MAC1;
269 20 robfinch 
                        end
270 
                `ASL_ZPX,`ROL_ZPX,`LSR_ZPX,`ROR_ZPX,`INC_ZPX,`DEC_ZPX:
271 
                        begin
272 
                                radr <= dp + rfoa + ir[23:12];
273 
                                pc <= pc + 32'd3;
274 21 robfinch 
                                load_what <= `WORD_310;
275 
                                state <= LOAD_MAC1;
276 20 robfinch 
                        end
277 23 robfinch 
                `ADD_DSP,`SUB_DSP,`OR_DSP,`AND_DSP,`EOR_DSP:
278 
                        begin
279 
                                a <= rfoa;
280 
                                Rt <= ir[15:12];
281 
                                radr <= {{24{ir[23]}},ir[23:16]} + isp;
282 
                                pc <= pc + 32'd3;
283 
                                load_what <= `WORD_310;
284 
                                state <= LOAD_MAC1;
285 
                        end
286 20 robfinch 
                `ADD_IX,`SUB_IX,`OR_IX,`AND_IX,`EOR_IX,`ST_IX:
287 
                        begin
288 
                                a <= rfoa;
289 
                                if (ir[7:0]==`ST_IX)
290 
                                        res <= rfoa;            // for ST_IX, Rt=0
291 
                                else
292 
                                        Rt <= ir[19:16];
293 
                                pc <= pc + 32'd4;
294 
                                radr <= dp + ir[31:20] + rfob;
295 21 robfinch 
                                load_what <= `IA_310;
296 
                                state <= LOAD_MAC1;
297 20 robfinch 
                        end
298 
                `ADD_RIND,`SUB_RIND,`OR_RIND,`AND_RIND,`EOR_RIND,`ST_RIND:
299 
                        begin
300 
                                radr <= rfob;
301 
                                wadr <= rfob;           // for store
302 
                                wdat <= rfoa;
303 
                                a <= rfoa;
304 
                                if (ir[7:0]==`ST_RIND) begin
305 
                                        res <= rfoa;            // for ST_IX, Rt=0
306 
                                        pc <= pc + 32'd2;
307 
                                        state <= STORE1;
308 
                                end
309 
                                else begin
310 
                                        Rt <= ir[19:16];
311 
                                        pc <= pc + 32'd3;
312 21 robfinch 
                                        load_what <= `WORD_310;
313 
                                        state <= LOAD_MAC1;
314 20 robfinch 
                                end
315 
                        end
316 
                `ADD_IY,`SUB_IY,`OR_IY,`AND_IY,`EOR_IY,`ST_IY:
317 
                        begin
318 
                                a <= rfoa;
319 
                                if (ir[7:0]==`ST_IY)
320 
                                        res <= rfoa;            // for ST_IY, Rt=0
321 
                                else
322 
                                        Rt <= ir[19:16];
323 
                                pc <= pc + 32'd4;
324 21 robfinch 
                                isIY <= 1'b1;
325 20 robfinch 
                                radr <= dp + ir[31:20];
326 21 robfinch 
                                load_what <= `IA_310;
327 
                                state <= LOAD_MAC1;
328 20 robfinch 
                        end
329 
                `ADD_ABS,`SUB_ABS,`OR_ABS,`AND_ABS,`EOR_ABS:
330 
                        begin
331 
                                a <= rfoa;
332 
                                radr <= ir[47:16];
333 
                                Rt <= ir[15:12];
334 
                                pc <= pc + 32'd6;
335 21 robfinch 
                                load_what <= `WORD_310;
336 
                                state <= LOAD_MAC1;
337 20 robfinch 
                        end
338 
                `ASL_ABS,`ROL_ABS,`LSR_ABS,`ROR_ABS,`INC_ABS,`DEC_ABS:
339 
                        begin
340 
                                radr <= ir[39:8];
341 
                                pc <= pc + 32'd5;
342 21 robfinch 
                                load_what <= `WORD_310;
343 
                                state <= LOAD_MAC1;
344 20 robfinch 
                        end
345 
                `ADD_ABSX,`SUB_ABSX,`OR_ABSX,`AND_ABSX,`EOR_ABSX:
346 
                        begin
347 
                                a <= rfoa;
348 
                                radr <= ir[55:24] + rfob;
349 
                                Rt <= ir[19:16];
350 
                                pc <= pc + 32'd7;
351 21 robfinch 
                                load_what <= `WORD_310;
352 
                                state <= LOAD_MAC1;
353 20 robfinch 
                        end
354 
                `ASL_ABSX,`ROL_ABSX,`LSR_ABSX,`ROR_ABSX,`INC_ABSX,`DEC_ABSX:
355 
                        begin
356 
                                radr <= ir[47:16] + rfob;
357 
                                pc <= pc + 32'd6;
358 21 robfinch 
                                load_what <= `WORD_310;
359 
                                state <= LOAD_MAC1;
360 20 robfinch 
                        end
361 
                `CPX_IMM32:
362 
                        begin
363 
                                res <= x - ir[39:8];
364 
                                pc <= pc + 32'd5;
365 
                                state <= IFETCH;
366 
                        end
367 
                `CPY_IMM32:
368 
                        begin
369 
                                res <= y - ir[39:8];
370 
                                pc <= pc + 32'd5;
371 
                                state <= IFETCH;
372 
                        end
373 
                `CPX_ZPX:
374 
                        begin
375 
                                radr <= dp + ir[23:12] + rfoa;
376 
                                pc <= pc + 32'd3;
377 21 robfinch 
                                load_what <= `WORD_310;
378 
                                state <= LOAD_MAC1;
379 20 robfinch 
                        end
380 
                `CPY_ZPX:
381 
                        begin
382 
                                radr <= dp + ir[23:12] + rfoa;
383 
                                pc <= pc + 32'd3;
384 21 robfinch 
                                load_what <= `WORD_310;
385 
                                state <= LOAD_MAC1;
386 20 robfinch 
                        end
387 
                `CPX_ABS:
388 
                        begin
389 
                                radr <= ir[39:8];
390 
                                pc <= pc + 32'd5;
391 21 robfinch 
                                load_what <= `WORD_310;
392 
                                state <= LOAD_MAC1;
393 20 robfinch 
                        end
394 
                `CPY_ABS:
395 
                        begin
396 
                                radr <= ir[39:8];
397 
                                pc <= pc + 32'd5;
398 21 robfinch 
                                load_what <= `WORD_310;
399 
                                state <= LOAD_MAC1;
400 20 robfinch 
                        end
401 
                `BRK:
402 
                        begin
403 
                                bf <= 1'b1;
404 
                                radr <= isp_dec;
405 
                                wadr <= isp_dec;
406 
                                wdat <= pc + 32'd1;
407 
                                cyc_o <= 1'b1;
408 
                                stb_o <= 1'b1;
409 
                                we_o <= 1'b1;
410 
                                sel_o <= 4'hF;
411 
                                adr_o <= {isp_dec,2'b00};
412 
                                dat_o <= pc + 32'd1;
413 
                                vect <= {vbr[31:9],`BRK_VECTNO,2'b00};
414 
                                state <= IRQ1;
415 
                        end
416 21 robfinch 
                `INT0,`INT1:
417 
                        begin
418 
                                radr <= isp_dec;
419 
                                wadr <= isp_dec;
420 
                                wdat <= pc + 32'd2;
421 
                                cyc_o <= 1'b1;
422 
                                stb_o <= 1'b1;
423 
                                we_o <= 1'b1;
424 
                                sel_o <= 4'hF;
425 
                                adr_o <= {isp_dec,2'b00};
426 
                                dat_o <= pc + 32'd2;
427 
                                vect <= {vbr[31:9],ir[15:7],2'b00};
428 
                                state <= IRQ1;
429 
                        end
430 20 robfinch 
                `JMP:
431 
                        begin
432 
                                pc[15:0] <= ir[23:8];
433 
                                state <= IFETCH;
434 
                        end
435 
                `JML:
436 
                        begin
437 
                                pc <= ir[39:8];
438 
                                state <= IFETCH;
439 
                        end
440 
                `JMP_IND:
441 
                        begin
442 
                                radr <= ir[39:8];
443 21 robfinch 
                                load_what <= `PC_310;
444 
                                state <= LOAD_MAC1;
445 20 robfinch 
                        end
446 
                `JMP_INDX:
447 
                        begin
448 
                                radr <= ir[39:8] + x;
449 21 robfinch 
                                load_what <= `PC_310;
450 
                                state <= LOAD_MAC1;
451 20 robfinch 
                        end
452 
                `JMP_RIND:
453 
                        begin
454 
                                pc <= rfoa;
455 
                                res <= pc + 32'd2;
456 
                                Rt <= ir[15:12];
457 
                                state <= IFETCH;
458 
                        end
459 
                `JSR:
460 
                        begin
461 
                                radr <= isp_dec;
462 
                                wadr <= isp_dec;
463 
                                wdat <= pc + 32'd3;
464 
                                cyc_o <= 1'b1;
465 
                                stb_o <= 1'b1;
466 
                                we_o <= 1'b1;
467 
                                sel_o <= 4'hF;
468 
                                adr_o <= {isp_dec,2'b00};
469 
                                dat_o <= pc + 32'd3;
470 
                                vect <= {pc[31:16],ir[23:8]};
471 
                                state <= JSR1;
472 
                        end
473 
                `JSR_RIND:
474 
                        begin
475 
                                radr <= isp_dec;
476 
                                wadr <= isp_dec;
477 
                                wdat <= pc + 32'd2;
478 
                                cyc_o <= 1'b1;
479 
                                stb_o <= 1'b1;
480 
                                we_o <= 1'b1;
481 
                                sel_o <= 4'hF;
482 
                                adr_o <= {isp_dec,2'b00};
483 
                                dat_o <= pc + 32'd2;
484 
                                vect <= rfoa;
485 
                                state <= JSR1;
486 
                                $stop;
487 
                        end
488 
                `JSL:
489 
                        begin
490 
                                radr <= isp_dec;
491 
                                wadr <= isp_dec;
492 
                                wdat <= pc + 32'd5;
493 
                                cyc_o <= 1'b1;
494 
                                stb_o <= 1'b1;
495 
                                we_o <= 1'b1;
496 
                                sel_o <= 4'hF;
497 
                                adr_o <= {isp_dec,2'b00};
498 
                                dat_o <= pc + 32'd5;
499 
                                vect <= ir[39:8];
500 
                                state <= JSR1;
501 
                        end
502 
                `BSR:
503 
                        begin
504 
                                radr <= isp_dec;
505 
                                wadr <= isp_dec;
506 
                                wdat <= pc + 32'd3;
507 
                                cyc_o <= 1'b1;
508 
                                stb_o <= 1'b1;
509 
                                we_o <= 1'b1;
510 
                                sel_o <= 4'hF;
511 
                                adr_o <= {isp_dec,2'b00};
512 
                                dat_o <= pc + 32'd3;
513 
                                vect <= pc + {{16{ir[23]}},ir[23:8]};
514 
                                state <= JSR1;
515 
                        end
516 
                `JSR_INDX:
517 
                        begin
518 
                                radr <= isp - 32'd1;
519 
                                wadr <= isp - 32'd1;
520 
                                wdat <= pc + 32'd5;
521 
                                cyc_o <= 1'b1;
522 
                                stb_o <= 1'b1;
523 
                                we_o <= 1'b1;
524 
                                sel_o <= 4'hF;
525 
                                adr_o <= {isp-32'd1,2'b00};
526 
                                dat_o <= pc + 32'd5;
527 
                                state <= JSR_INDX1;
528 
                        end
529 
//              `JSR16:
530 
//                      begin
531 
//                              radr <= isp - 32'd1;
532 
//                              wadr <= isp - 32'd1;
533 
//                              wdat <= pc + 32'd3;
534 
//                              cyc_o <= 1'b1;
535 
//                              stb_o <= 1'b1;
536 
//                              we_o <= 1'b1;
537 
//                              sel_o <= 4'hF;
538 
//                              adr_o <= {isp-32'd1,2'b00};
539 
//                              dat_o <= pc + 32'd3;
540 
//                              state <= JSR161;
541 
//                      end
542 
                `RTS,`RTL:
543 
                                begin
544 
                                radr <= isp;
545 21 robfinch 
                                load_what <= `PC_310;
546 
                                state <= LOAD_MAC1;
547 20 robfinch 
                                end
548 
                `RTI:   begin
549 
                                radr <= isp;
550 21 robfinch 
                                load_what <= `SR_310;
551 
                                state <= LOAD_MAC1;
552 20 robfinch 
                                end
553 
                `BEQ,`BNE,`BPL,`BMI,`BCC,`BCS,`BVC,`BVS,`BRA:
554 
                        begin
555 
                                state <= IFETCH;
556 
                                if (ir[15:8]==8'h00) begin
557 
                                        radr <= isp_dec;
558 
                                        wadr <= isp_dec;
559 
                                        wdat <= pc + 32'd2;
560 
                                        cyc_o <= 1'b1;
561 
                                        stb_o <= 1'b1;
562 
                                        we_o <= 1'b1;
563 
                                        sel_o <= 4'hF;
564 
                                        adr_o <= {isp_dec,2'b00};
565 
                                        dat_o <= pc + 32'd2;
566 
                                        vect <= {vbr[31:9],`SLP_VECTNO,2'b00};
567 
                                        state <= IRQ1;
568 
                                end
569 
                                else if (ir[15:8]==8'h1) begin
570 
                                        if (takb)
571 
                                                pc <= pc + {{16{ir[31]}},ir[31:16]};
572 
                                        else
573 
                                                pc <= pc + 32'd4;
574 
                                end
575 
                                else begin
576 
                                        if (takb)
577 
                                                pc <= pc + {{24{ir[15]}},ir[15:8]};
578 
                                        else
579 
                                                pc <= pc + 32'd2;
580 
                                end
581 
                        end
582 
/*              `BEQ_RR:
583 
                        begin
584 
                                state <= IFETCH;
585 
                                if (ir[23:16]==8'h00) begin
586 
                                        radr <= isp_dec;
587 
                                        wadr <= isp_dec;
588 
                                        wdat <= pc + 32'd2;
589 
                                        cyc_o <= 1'b1;
590 
                                        stb_o <= 1'b1;
591 
                                        we_o <= 1'b1;
592 
                                        sel_o <= 4'hF;
593 
                                        adr_o <= {isp_dec,2'b00};
594 
                                        dat_o <= pc + 32'd2;
595 
                                        vect <= `SLP_VECT;
596 
                                        state <= IRQ1;
597 
                                end
598 
                                else if (ir[23:16]==8'h1) begin
599 
                                        if (rfoa==rfob)
600 
                                                pc <= pc + {{16{ir[39]}},ir[39:24]};
601 
                                        else
602 
                                                pc <= pc + 32'd5;
603 
                                end
604 
                                else begin
605 
                                        if (takb)
606 
                                                pc <= pc + {{24{ir[23]}},ir[23:16]};
607 
                                        else
608 
                                                pc <= pc + 32'd3;
609 
                                end
610 
                        end*/
611 
                `BRL:
612 
                        begin
613 
                                if (ir[23:8]==16'h0000) begin
614 
                                        radr <= isp_dec;
615 
                                        wadr <= isp_dec;
616 
                                        wdat <= pc + 32'd3;
617 
                                        cyc_o <= 1'b1;
618 
                                        stb_o <= 1'b1;
619 
                                        we_o <= 1'b1;
620 
                                        sel_o <= 4'hF;
621 
                                        adr_o <= {isp_dec,2'b00};
622 
                                        dat_o <= pc + 32'd3;
623 
                                        vect <= {vbr[31:9],`SLP_VECTNO,2'b00};
624 
                                        state <= IRQ1;
625 
                                end
626 
                                else begin
627 
                                        pc <= pc + {{16{ir[23]}},ir[23:8]};
628 
                                        state <= IFETCH;
629 
                                end
630 
                        end
631 
                `PHP:
632 
                        begin
633 
                                cyc_o <= 1'b1;
634 
                                stb_o <= 1'b1;
635 
                                sel_o <= 4'hF;
636 
                                we_o <= 1'b1;
637 
                                radr <= isp_dec;
638 
                                wadr <= isp_dec;
639 
                                wdat <= sr;
640 
                                adr_o <= {isp_dec,2'b00};
641 
                                dat_o <= sr;
642 
                                isp <= isp_dec;
643 
                                state <= PHP1;
644 
                        end
645 
                `PHA:
646 
                        begin
647 
                                cyc_o <= 1'b1;
648 
                                stb_o <= 1'b1;
649 
                                sel_o <= 4'hF;
650 
                                we_o <= 1'b1;
651 
                                radr <= isp_dec;
652 
                                wadr <= isp_dec;
653 
                                wdat <= acc;
654 
                                adr_o <= {isp_dec,2'b00};
655 
                                dat_o <= acc;
656 
                                isp <= isp_dec;
657 
                                state <= PHP1;
658 
                        end
659 
                `PHX:
660 
                        begin
661 
                                cyc_o <= 1'b1;
662 
                                stb_o <= 1'b1;
663 
                                sel_o <= 4'hF;
664 
                                we_o <= 1'b1;
665 
                                radr <= isp_dec;
666 
                                wadr <= isp_dec;
667 
                                wdat <= x;
668 
                                adr_o <= {isp_dec,2'b00};
669 
                                dat_o <= x;
670 
                                isp <= isp_dec;
671 
                                state <= PHP1;
672 
                        end
673 
                `PHY:
674 
                        begin
675 
                                cyc_o <= 1'b1;
676 
                                stb_o <= 1'b1;
677 
                                sel_o <= 4'hF;
678 
                                we_o <= 1'b1;
679 
                                radr <= isp_dec;
680 
                                wadr <= isp_dec;
681 
                                wdat <= y;
682 
                                adr_o <= {isp_dec,2'b00};
683 
                                dat_o <= y;
684 
                                isp <= isp_dec;
685 
                                state <= PHP1;
686 
                        end
687 
                `PUSH:
688 
                        begin
689 
                                cyc_o <= 1'b1;
690 
                                stb_o <= 1'b1;
691 
                                sel_o <= 4'hF;
692 
                                we_o <= 1'b1;
693 
                                radr <= isp_dec;
694 
                                wadr <= isp_dec;
695 
                                wdat <= rfoa;
696 
                                adr_o <= {isp_dec,2'b00};
697 
                                dat_o <= rfoa;
698 
                                state <= PHP1;
699 
                                isp <= isp_dec;
700 
                                pc <= pc + 32'd1;
701 
                        end
702 
                `PLP:
703 
                        begin
704 
                                radr <= isp;
705 
                                pc <= pc + 32'd1;
706 21 robfinch 
                                load_what <= `SR_310;
707 
                                state <= LOAD_MAC1;
708 20 robfinch 
                        end
709 
                `PLA,`PLX,`PLY:
710 
                        begin
711 
                                radr <= isp;
712 
                                isp <= isp_inc;
713 21 robfinch 
                                load_what <= `WORD_311;
714 
                                state <= LOAD_MAC1;
715 20 robfinch 
                                pc <= pc + 32'd1;
716 
                        end
717 
                `POP:
718 
                        begin
719 
                                Rt <= ir[15:12];
720 
                                radr <= isp;
721 
                                isp <= isp_inc;
722 21 robfinch 
                                load_what <= `WORD_311;
723 
                                state <= LOAD_MAC1;
724 20 robfinch 
                                pc <= pc + 32'd2;
725 
                        end
726 23 robfinch 
                `MVN:   state <= MVN1;
727 
                `MVP:   state <= MVP1;
728 20 robfinch 
                default:        // unimplemented opcode
729 21 robfinch 
                        begin
730 
                                radr <= isp_dec;
731 
                                wadr <= isp_dec;
732 
                                wdat <= pc + 32'd1;
733 
                                cyc_o <= 1'b1;
734 
                                stb_o <= 1'b1;
735 
                                we_o <= 1'b1;
736 
                                sel_o <= 4'hF;
737 
                                adr_o <= {isp_dec,2'b00};
738 
                                dat_o <= pc + 32'd1;
739 
                                vect <= {vbr[31:9],9'd495,2'b00};
740 
                                state <= IRQ1;
741 
                        end
742 20 robfinch 
                endcase
743 
        end

powered by: WebSVN 2.1.0

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