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impact 11 renamed the intel flash...
[fpga-games] / galaxian / t80_ip / T80_MCode.vhd
1 -- ****
2 -- T80(b) core. In an effort to merge and maintain bug fixes ....
3 --
4 --
5 -- Ver 300 started tidyup
6 -- MikeJ March 2005
7 -- Latest version from www.fpgaarcade.com (original www.opencores.org)
8 --
9 -- ****
10 --
11 -- Z80 compatible microprocessor core
12 --
13 -- Version : 0242
14 --
15 -- Copyright (c) 2001-2002 Daniel Wallner (jesus@opencores.org)
16 --
17 -- All rights reserved
18 --
19 -- Redistribution and use in source and synthezised forms, with or without
20 -- modification, are permitted provided that the following conditions are met:
21 --
22 -- Redistributions of source code must retain the above copyright notice,
23 -- this list of conditions and the following disclaimer.
24 --
25 -- Redistributions in synthesized form must reproduce the above copyright
26 -- notice, this list of conditions and the following disclaimer in the
27 -- documentation and/or other materials provided with the distribution.
28 --
29 -- Neither the name of the author nor the names of other contributors may
30 -- be used to endorse or promote products derived from this software without
31 -- specific prior written permission.
32 --
33 -- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
34 -- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
35 -- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
36 -- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
37 -- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
38 -- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
39 -- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
40 -- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
41 -- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 -- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
43 -- POSSIBILITY OF SUCH DAMAGE.
44 --
45 -- Please report bugs to the author, but before you do so, please
46 -- make sure that this is not a derivative work and that
47 -- you have the latest version of this file.
48 --
49 -- The latest version of this file can be found at:
50 -- http://www.opencores.org/cvsweb.shtml/t80/
51 --
52 -- Limitations :
53 --
54 -- File history :
55 --
56 -- 0208 : First complete release
57 --
58 -- 0211 : Fixed IM 1
59 --
60 -- 0214 : Fixed mostly flags, only the block instructions now fail the zex regression test
61 --
62 -- 0235 : Added IM 2 fix by Mike Johnson
63 --
64 -- 0238 : Added NoRead signal
65 --
66 -- 0238b: Fixed instruction timing for POP and DJNZ
67 --
68 -- 0240 : Added (IX/IY+d) states, removed op-codes from mode 2 and added all remaining mode 3 op-codes
69
70 -- 0240mj1 fix for HL inc/dec for INI, IND, INIR, INDR, OUTI, OUTD, OTIR, OTDR
71 --
72 -- 0242 : Fixed I/O instruction timing, cleanup
73 --
74
75 library IEEE;
76 use IEEE.std_logic_1164.all;
77 use IEEE.numeric_std.all;
78 use work.T80_Pack.all;
79
80 entity T80_MCode is
81 generic(
82 Mode : integer := 0;
83 Flag_C : integer := 0;
84 Flag_N : integer := 1;
85 Flag_P : integer := 2;
86 Flag_X : integer := 3;
87 Flag_H : integer := 4;
88 Flag_Y : integer := 5;
89 Flag_Z : integer := 6;
90 Flag_S : integer := 7
91 );
92 port(
93 IR : in std_logic_vector(7 downto 0);
94 ISet : in std_logic_vector(1 downto 0);
95 MCycle : in std_logic_vector(2 downto 0);
96 F : in std_logic_vector(7 downto 0);
97 NMICycle : in std_logic;
98 IntCycle : in std_logic;
99 MCycles : out std_logic_vector(2 downto 0);
100 TStates : out std_logic_vector(2 downto 0);
101 Prefix : out std_logic_vector(1 downto 0); -- None,BC,ED,DD/FD
102 Inc_PC : out std_logic;
103 Inc_WZ : out std_logic;
104 IncDec_16 : out std_logic_vector(3 downto 0); -- BC,DE,HL,SP 0 is inc
105 Read_To_Reg : out std_logic;
106 Read_To_Acc : out std_logic;
107 Set_BusA_To : out std_logic_vector(3 downto 0); -- B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F
108 Set_BusB_To : out std_logic_vector(3 downto 0); -- B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0
109 ALU_Op : out std_logic_vector(3 downto 0);
110 -- ADD, ADC, SUB, SBC, AND, XOR, OR, CP, ROT, BIT, SET, RES, DAA, RLD, RRD, None
111 Save_ALU : out std_logic;
112 PreserveC : out std_logic;
113 Arith16 : out std_logic;
114 Set_Addr_To : out std_logic_vector(2 downto 0); -- aNone,aXY,aIOA,aSP,aBC,aDE,aZI
115 IORQ : out std_logic;
116 Jump : out std_logic;
117 JumpE : out std_logic;
118 JumpXY : out std_logic;
119 Call : out std_logic;
120 RstP : out std_logic;
121 LDZ : out std_logic;
122 LDW : out std_logic;
123 LDSPHL : out std_logic;
124 Special_LD : out std_logic_vector(2 downto 0); -- A,I;A,R;I,A;R,A;None
125 ExchangeDH : out std_logic;
126 ExchangeRp : out std_logic;
127 ExchangeAF : out std_logic;
128 ExchangeRS : out std_logic;
129 I_DJNZ : out std_logic;
130 I_CPL : out std_logic;
131 I_CCF : out std_logic;
132 I_SCF : out std_logic;
133 I_RETN : out std_logic;
134 I_BT : out std_logic;
135 I_BC : out std_logic;
136 I_BTR : out std_logic;
137 I_RLD : out std_logic;
138 I_RRD : out std_logic;
139 I_INRC : out std_logic;
140 SetDI : out std_logic;
141 SetEI : out std_logic;
142 IMode : out std_logic_vector(1 downto 0);
143 Halt : out std_logic;
144 NoRead : out std_logic;
145 Write : out std_logic
146 );
147 end T80_MCode;
148
149 architecture rtl of T80_MCode is
150
151 constant aNone : std_logic_vector(2 downto 0) := "111";
152 constant aBC : std_logic_vector(2 downto 0) := "000";
153 constant aDE : std_logic_vector(2 downto 0) := "001";
154 constant aXY : std_logic_vector(2 downto 0) := "010";
155 constant aIOA : std_logic_vector(2 downto 0) := "100";
156 constant aSP : std_logic_vector(2 downto 0) := "101";
157 constant aZI : std_logic_vector(2 downto 0) := "110";
158
159 function is_cc_true(
160 F : std_logic_vector(7 downto 0);
161 cc : bit_vector(2 downto 0)
162 ) return boolean is
163 begin
164 if Mode = 3 then
165 case cc is
166 when "000" => return F(7) = '0'; -- NZ
167 when "001" => return F(7) = '1'; -- Z
168 when "010" => return F(4) = '0'; -- NC
169 when "011" => return F(4) = '1'; -- C
170 when "100" => return false;
171 when "101" => return false;
172 when "110" => return false;
173 when "111" => return false;
174 end case;
175 else
176 case cc is
177 when "000" => return F(6) = '0'; -- NZ
178 when "001" => return F(6) = '1'; -- Z
179 when "010" => return F(0) = '0'; -- NC
180 when "011" => return F(0) = '1'; -- C
181 when "100" => return F(2) = '0'; -- PO
182 when "101" => return F(2) = '1'; -- PE
183 when "110" => return F(7) = '0'; -- P
184 when "111" => return F(7) = '1'; -- M
185 end case;
186 end if;
187 end;
188
189 begin
190
191 process (IR, ISet, MCycle, F, NMICycle, IntCycle)
192 variable DDD : std_logic_vector(2 downto 0);
193 variable SSS : std_logic_vector(2 downto 0);
194 variable DPair : std_logic_vector(1 downto 0);
195 variable IRB : bit_vector(7 downto 0);
196 begin
197 DDD := IR(5 downto 3);
198 SSS := IR(2 downto 0);
199 DPair := IR(5 downto 4);
200 IRB := to_bitvector(IR);
201
202 MCycles <= "001";
203 if MCycle = "001" then
204 TStates <= "100";
205 else
206 TStates <= "011";
207 end if;
208 Prefix <= "00";
209 Inc_PC <= '0';
210 Inc_WZ <= '0';
211 IncDec_16 <= "0000";
212 Read_To_Acc <= '0';
213 Read_To_Reg <= '0';
214 Set_BusB_To <= "0000";
215 Set_BusA_To <= "0000";
216 ALU_Op <= "0" & IR(5 downto 3);
217 Save_ALU <= '0';
218 PreserveC <= '0';
219 Arith16 <= '0';
220 IORQ <= '0';
221 Set_Addr_To <= aNone;
222 Jump <= '0';
223 JumpE <= '0';
224 JumpXY <= '0';
225 Call <= '0';
226 RstP <= '0';
227 LDZ <= '0';
228 LDW <= '0';
229 LDSPHL <= '0';
230 Special_LD <= "000";
231 ExchangeDH <= '0';
232 ExchangeRp <= '0';
233 ExchangeAF <= '0';
234 ExchangeRS <= '0';
235 I_DJNZ <= '0';
236 I_CPL <= '0';
237 I_CCF <= '0';
238 I_SCF <= '0';
239 I_RETN <= '0';
240 I_BT <= '0';
241 I_BC <= '0';
242 I_BTR <= '0';
243 I_RLD <= '0';
244 I_RRD <= '0';
245 I_INRC <= '0';
246 SetDI <= '0';
247 SetEI <= '0';
248 IMode <= "11";
249 Halt <= '0';
250 NoRead <= '0';
251 Write <= '0';
252
253 case ISet is
254 when "00" =>
255
256 ------------------------------------------------------------------------------
257 --
258 -- Unprefixed instructions
259 --
260 ------------------------------------------------------------------------------
261
262 case IRB is
263 -- 8 BIT LOAD GROUP
264 when "01000000"|"01000001"|"01000010"|"01000011"|"01000100"|"01000101"|"01000111"
265 |"01001000"|"01001001"|"01001010"|"01001011"|"01001100"|"01001101"|"01001111"
266 |"01010000"|"01010001"|"01010010"|"01010011"|"01010100"|"01010101"|"01010111"
267 |"01011000"|"01011001"|"01011010"|"01011011"|"01011100"|"01011101"|"01011111"
268 |"01100000"|"01100001"|"01100010"|"01100011"|"01100100"|"01100101"|"01100111"
269 |"01101000"|"01101001"|"01101010"|"01101011"|"01101100"|"01101101"|"01101111"
270 |"01111000"|"01111001"|"01111010"|"01111011"|"01111100"|"01111101"|"01111111" =>
271 -- LD r,r'
272 Set_BusB_To(2 downto 0) <= SSS;
273 ExchangeRp <= '1';
274 Set_BusA_To(2 downto 0) <= DDD;
275 Read_To_Reg <= '1';
276 when "00000110"|"00001110"|"00010110"|"00011110"|"00100110"|"00101110"|"00111110" =>
277 -- LD r,n
278 MCycles <= "010";
279 case to_integer(unsigned(MCycle)) is
280 when 2 =>
281 Inc_PC <= '1';
282 Set_BusA_To(2 downto 0) <= DDD;
283 Read_To_Reg <= '1';
284 when others => null;
285 end case;
286 when "01000110"|"01001110"|"01010110"|"01011110"|"01100110"|"01101110"|"01111110" =>
287 -- LD r,(HL)
288 MCycles <= "010";
289 case to_integer(unsigned(MCycle)) is
290 when 1 =>
291 Set_Addr_To <= aXY;
292 when 2 =>
293 Set_BusA_To(2 downto 0) <= DDD;
294 Read_To_Reg <= '1';
295 when others => null;
296 end case;
297 when "01110000"|"01110001"|"01110010"|"01110011"|"01110100"|"01110101"|"01110111" =>
298 -- LD (HL),r
299 MCycles <= "010";
300 case to_integer(unsigned(MCycle)) is
301 when 1 =>
302 Set_Addr_To <= aXY;
303 Set_BusB_To(2 downto 0) <= SSS;
304 Set_BusB_To(3) <= '0';
305 when 2 =>
306 Write <= '1';
307 when others => null;
308 end case;
309 when "00110110" =>
310 -- LD (HL),n
311 MCycles <= "011";
312 case to_integer(unsigned(MCycle)) is
313 when 2 =>
314 Inc_PC <= '1';
315 Set_Addr_To <= aXY;
316 Set_BusB_To(2 downto 0) <= SSS;
317 Set_BusB_To(3) <= '0';
318 when 3 =>
319 Write <= '1';
320 when others => null;
321 end case;
322 when "00001010" =>
323 -- LD A,(BC)
324 MCycles <= "010";
325 case to_integer(unsigned(MCycle)) is
326 when 1 =>
327 Set_Addr_To <= aBC;
328 when 2 =>
329 Read_To_Acc <= '1';
330 when others => null;
331 end case;
332 when "00011010" =>
333 -- LD A,(DE)
334 MCycles <= "010";
335 case to_integer(unsigned(MCycle)) is
336 when 1 =>
337 Set_Addr_To <= aDE;
338 when 2 =>
339 Read_To_Acc <= '1';
340 when others => null;
341 end case;
342 when "00111010" =>
343 if Mode = 3 then
344 -- LDD A,(HL)
345 MCycles <= "010";
346 case to_integer(unsigned(MCycle)) is
347 when 1 =>
348 Set_Addr_To <= aXY;
349 when 2 =>
350 Read_To_Acc <= '1';
351 IncDec_16 <= "1110";
352 when others => null;
353 end case;
354 else
355 -- LD A,(nn)
356 MCycles <= "100";
357 case to_integer(unsigned(MCycle)) is
358 when 2 =>
359 Inc_PC <= '1';
360 LDZ <= '1';
361 when 3 =>
362 Set_Addr_To <= aZI;
363 Inc_PC <= '1';
364 when 4 =>
365 Read_To_Acc <= '1';
366 when others => null;
367 end case;
368 end if;
369 when "00000010" =>
370 -- LD (BC),A
371 MCycles <= "010";
372 case to_integer(unsigned(MCycle)) is
373 when 1 =>
374 Set_Addr_To <= aBC;
375 Set_BusB_To <= "0111";
376 when 2 =>
377 Write <= '1';
378 when others => null;
379 end case;
380 when "00010010" =>
381 -- LD (DE),A
382 MCycles <= "010";
383 case to_integer(unsigned(MCycle)) is
384 when 1 =>
385 Set_Addr_To <= aDE;
386 Set_BusB_To <= "0111";
387 when 2 =>
388 Write <= '1';
389 when others => null;
390 end case;
391 when "00110010" =>
392 if Mode = 3 then
393 -- LDD (HL),A
394 MCycles <= "010";
395 case to_integer(unsigned(MCycle)) is
396 when 1 =>
397 Set_Addr_To <= aXY;
398 Set_BusB_To <= "0111";
399 when 2 =>
400 Write <= '1';
401 IncDec_16 <= "1110";
402 when others => null;
403 end case;
404 else
405 -- LD (nn),A
406 MCycles <= "100";
407 case to_integer(unsigned(MCycle)) is
408 when 2 =>
409 Inc_PC <= '1';
410 LDZ <= '1';
411 when 3 =>
412 Set_Addr_To <= aZI;
413 Inc_PC <= '1';
414 Set_BusB_To <= "0111";
415 when 4 =>
416 Write <= '1';
417 when others => null;
418 end case;
419 end if;
420
421 -- 16 BIT LOAD GROUP
422 when "00000001"|"00010001"|"00100001"|"00110001" =>
423 -- LD dd,nn
424 MCycles <= "011";
425 case to_integer(unsigned(MCycle)) is
426 when 2 =>
427 Inc_PC <= '1';
428 Read_To_Reg <= '1';
429 if DPAIR = "11" then
430 Set_BusA_To(3 downto 0) <= "1000";
431 else
432 Set_BusA_To(2 downto 1) <= DPAIR;
433 Set_BusA_To(0) <= '1';
434 end if;
435 when 3 =>
436 Inc_PC <= '1';
437 Read_To_Reg <= '1';
438 if DPAIR = "11" then
439 Set_BusA_To(3 downto 0) <= "1001";
440 else
441 Set_BusA_To(2 downto 1) <= DPAIR;
442 Set_BusA_To(0) <= '0';
443 end if;
444 when others => null;
445 end case;
446 when "00101010" =>
447 if Mode = 3 then
448 -- LDI A,(HL)
449 MCycles <= "010";
450 case to_integer(unsigned(MCycle)) is
451 when 1 =>
452 Set_Addr_To <= aXY;
453 when 2 =>
454 Read_To_Acc <= '1';
455 IncDec_16 <= "0110";
456 when others => null;
457 end case;
458 else
459 -- LD HL,(nn)
460 MCycles <= "101";
461 case to_integer(unsigned(MCycle)) is
462 when 2 =>
463 Inc_PC <= '1';
464 LDZ <= '1';
465 when 3 =>
466 Set_Addr_To <= aZI;
467 Inc_PC <= '1';
468 LDW <= '1';
469 when 4 =>
470 Set_BusA_To(2 downto 0) <= "101"; -- L
471 Read_To_Reg <= '1';
472 Inc_WZ <= '1';
473 Set_Addr_To <= aZI;
474 when 5 =>
475 Set_BusA_To(2 downto 0) <= "100"; -- H
476 Read_To_Reg <= '1';
477 when others => null;
478 end case;
479 end if;
480 when "00100010" =>
481 if Mode = 3 then
482 -- LDI (HL),A
483 MCycles <= "010";
484 case to_integer(unsigned(MCycle)) is
485 when 1 =>
486 Set_Addr_To <= aXY;
487 Set_BusB_To <= "0111";
488 when 2 =>
489 Write <= '1';
490 IncDec_16 <= "0110";
491 when others => null;
492 end case;
493 else
494 -- LD (nn),HL
495 MCycles <= "101";
496 case to_integer(unsigned(MCycle)) is
497 when 2 =>
498 Inc_PC <= '1';
499 LDZ <= '1';
500 when 3 =>
501 Set_Addr_To <= aZI;
502 Inc_PC <= '1';
503 LDW <= '1';
504 Set_BusB_To <= "0101"; -- L
505 when 4 =>
506 Inc_WZ <= '1';
507 Set_Addr_To <= aZI;
508 Write <= '1';
509 Set_BusB_To <= "0100"; -- H
510 when 5 =>
511 Write <= '1';
512 when others => null;
513 end case;
514 end if;
515 when "11111001" =>
516 -- LD SP,HL
517 TStates <= "110";
518 LDSPHL <= '1';
519 when "11000101"|"11010101"|"11100101"|"11110101" =>
520 -- PUSH qq
521 MCycles <= "011";
522 case to_integer(unsigned(MCycle)) is
523 when 1 =>
524 TStates <= "101";
525 IncDec_16 <= "1111";
526 Set_Addr_TO <= aSP;
527 if DPAIR = "11" then
528 Set_BusB_To <= "0111";
529 else
530 Set_BusB_To(2 downto 1) <= DPAIR;
531 Set_BusB_To(0) <= '0';
532 Set_BusB_To(3) <= '0';
533 end if;
534 when 2 =>
535 IncDec_16 <= "1111";
536 Set_Addr_To <= aSP;
537 if DPAIR = "11" then
538 Set_BusB_To <= "1011";
539 else
540 Set_BusB_To(2 downto 1) <= DPAIR;
541 Set_BusB_To(0) <= '1';
542 Set_BusB_To(3) <= '0';
543 end if;
544 Write <= '1';
545 when 3 =>
546 Write <= '1';
547 when others => null;
548 end case;
549 when "11000001"|"11010001"|"11100001"|"11110001" =>
550 -- POP qq
551 MCycles <= "011";
552 case to_integer(unsigned(MCycle)) is
553 when 1 =>
554 Set_Addr_To <= aSP;
555 when 2 =>
556 IncDec_16 <= "0111";
557 Set_Addr_To <= aSP;
558 Read_To_Reg <= '1';
559 if DPAIR = "11" then
560 Set_BusA_To(3 downto 0) <= "1011";
561 else
562 Set_BusA_To(2 downto 1) <= DPAIR;
563 Set_BusA_To(0) <= '1';
564 end if;
565 when 3 =>
566 IncDec_16 <= "0111";
567 Read_To_Reg <= '1';
568 if DPAIR = "11" then
569 Set_BusA_To(3 downto 0) <= "0111";
570 else
571 Set_BusA_To(2 downto 1) <= DPAIR;
572 Set_BusA_To(0) <= '0';
573 end if;
574 when others => null;
575 end case;
576
577 -- EXCHANGE, BLOCK TRANSFER AND SEARCH GROUP
578 when "11101011" =>
579 if Mode /= 3 then
580 -- EX DE,HL
581 ExchangeDH <= '1';
582 end if;
583 when "00001000" =>
584 if Mode = 3 then
585 -- LD (nn),SP
586 MCycles <= "101";
587 case to_integer(unsigned(MCycle)) is
588 when 2 =>
589 Inc_PC <= '1';
590 LDZ <= '1';
591 when 3 =>
592 Set_Addr_To <= aZI;
593 Inc_PC <= '1';
594 LDW <= '1';
595 Set_BusB_To <= "1000";
596 when 4 =>
597 Inc_WZ <= '1';
598 Set_Addr_To <= aZI;
599 Write <= '1';
600 Set_BusB_To <= "1001";
601 when 5 =>
602 Write <= '1';
603 when others => null;
604 end case;
605 elsif Mode < 2 then
606 -- EX AF,AF'
607 ExchangeAF <= '1';
608 end if;
609 when "11011001" =>
610 if Mode = 3 then
611 -- RETI
612 MCycles <= "011";
613 case to_integer(unsigned(MCycle)) is
614 when 1 =>
615 Set_Addr_TO <= aSP;
616 when 2 =>
617 IncDec_16 <= "0111";
618 Set_Addr_To <= aSP;
619 LDZ <= '1';
620 when 3 =>
621 Jump <= '1';
622 IncDec_16 <= "0111";
623 I_RETN <= '1';
624 SetEI <= '1';
625 when others => null;
626 end case;
627 elsif Mode < 2 then
628 -- EXX
629 ExchangeRS <= '1';
630 end if;
631 when "11100011" =>
632 if Mode /= 3 then
633 -- EX (SP),HL
634 MCycles <= "101";
635 case to_integer(unsigned(MCycle)) is
636 when 1 =>
637 Set_Addr_To <= aSP;
638 when 2 =>
639 Read_To_Reg <= '1';
640 Set_BusA_To <= "0101";
641 Set_BusB_To <= "0101";
642 Set_Addr_To <= aSP;
643 when 3 =>
644 IncDec_16 <= "0111";
645 Set_Addr_To <= aSP;
646 TStates <= "100";
647 Write <= '1';
648 when 4 =>
649 Read_To_Reg <= '1';
650 Set_BusA_To <= "0100";
651 Set_BusB_To <= "0100";
652 Set_Addr_To <= aSP;
653 when 5 =>
654 IncDec_16 <= "1111";
655 TStates <= "101";
656 Write <= '1';
657 when others => null;
658 end case;
659 end if;
660
661 -- 8 BIT ARITHMETIC AND LOGICAL GROUP
662 when "10000000"|"10000001"|"10000010"|"10000011"|"10000100"|"10000101"|"10000111"
663 |"10001000"|"10001001"|"10001010"|"10001011"|"10001100"|"10001101"|"10001111"
664 |"10010000"|"10010001"|"10010010"|"10010011"|"10010100"|"10010101"|"10010111"
665 |"10011000"|"10011001"|"10011010"|"10011011"|"10011100"|"10011101"|"10011111"
666 |"10100000"|"10100001"|"10100010"|"10100011"|"10100100"|"10100101"|"10100111"
667 |"10101000"|"10101001"|"10101010"|"10101011"|"10101100"|"10101101"|"10101111"
668 |"10110000"|"10110001"|"10110010"|"10110011"|"10110100"|"10110101"|"10110111"
669 |"10111000"|"10111001"|"10111010"|"10111011"|"10111100"|"10111101"|"10111111" =>
670 -- ADD A,r
671 -- ADC A,r
672 -- SUB A,r
673 -- SBC A,r
674 -- AND A,r
675 -- OR A,r
676 -- XOR A,r
677 -- CP A,r
678 Set_BusB_To(2 downto 0) <= SSS;
679 Set_BusA_To(2 downto 0) <= "111";
680 Read_To_Reg <= '1';
681 Save_ALU <= '1';
682 when "10000110"|"10001110"|"10010110"|"10011110"|"10100110"|"10101110"|"10110110"|"10111110" =>
683 -- ADD A,(HL)
684 -- ADC A,(HL)
685 -- SUB A,(HL)
686 -- SBC A,(HL)
687 -- AND A,(HL)
688 -- OR A,(HL)
689 -- XOR A,(HL)
690 -- CP A,(HL)
691 MCycles <= "010";
692 case to_integer(unsigned(MCycle)) is
693 when 1 =>
694 Set_Addr_To <= aXY;
695 when 2 =>
696 Read_To_Reg <= '1';
697 Save_ALU <= '1';
698 Set_BusB_To(2 downto 0) <= SSS;
699 Set_BusA_To(2 downto 0) <= "111";
700 when others => null;
701 end case;
702 when "11000110"|"11001110"|"11010110"|"11011110"|"11100110"|"11101110"|"11110110"|"11111110" =>
703 -- ADD A,n
704 -- ADC A,n
705 -- SUB A,n
706 -- SBC A,n
707 -- AND A,n
708 -- OR A,n
709 -- XOR A,n
710 -- CP A,n
711 MCycles <= "010";
712 if MCycle = "010" then
713 Inc_PC <= '1';
714 Read_To_Reg <= '1';
715 Save_ALU <= '1';
716 Set_BusB_To(2 downto 0) <= SSS;
717 Set_BusA_To(2 downto 0) <= "111";
718 end if;
719 when "00000100"|"00001100"|"00010100"|"00011100"|"00100100"|"00101100"|"00111100" =>
720 -- INC r
721 Set_BusB_To <= "1010";
722 Set_BusA_To(2 downto 0) <= DDD;
723 Read_To_Reg <= '1';
724 Save_ALU <= '1';
725 PreserveC <= '1';
726 ALU_Op <= "0000";
727 when "00110100" =>
728 -- INC (HL)
729 MCycles <= "011";
730 case to_integer(unsigned(MCycle)) is
731 when 1 =>
732 Set_Addr_To <= aXY;
733 when 2 =>
734 TStates <= "100";
735 Set_Addr_To <= aXY;
736 Read_To_Reg <= '1';
737 Save_ALU <= '1';
738 PreserveC <= '1';
739 ALU_Op <= "0000";
740 Set_BusB_To <= "1010";
741 Set_BusA_To(2 downto 0) <= DDD;
742 when 3 =>
743 Write <= '1';
744 when others => null;
745 end case;
746 when "00000101"|"00001101"|"00010101"|"00011101"|"00100101"|"00101101"|"00111101" =>
747 -- DEC r
748 Set_BusB_To <= "1010";
749 Set_BusA_To(2 downto 0) <= DDD;
750 Read_To_Reg <= '1';
751 Save_ALU <= '1';
752 PreserveC <= '1';
753 ALU_Op <= "0010";
754 when "00110101" =>
755 -- DEC (HL)
756 MCycles <= "011";
757 case to_integer(unsigned(MCycle)) is
758 when 1 =>
759 Set_Addr_To <= aXY;
760 when 2 =>
761 TStates <= "100";
762 Set_Addr_To <= aXY;
763 ALU_Op <= "0010";
764 Read_To_Reg <= '1';
765 Save_ALU <= '1';
766 PreserveC <= '1';
767 Set_BusB_To <= "1010";
768 Set_BusA_To(2 downto 0) <= DDD;
769 when 3 =>
770 Write <= '1';
771 when others => null;
772 end case;
773
774 -- GENERAL PURPOSE ARITHMETIC AND CPU CONTROL GROUPS
775 when "00100111" =>
776 -- DAA
777 Set_BusA_To(2 downto 0) <= "111";
778 Read_To_Reg <= '1';
779 ALU_Op <= "1100";
780 Save_ALU <= '1';
781 when "00101111" =>
782 -- CPL
783 I_CPL <= '1';
784 when "00111111" =>
785 -- CCF
786 I_CCF <= '1';
787 when "00110111" =>
788 -- SCF
789 I_SCF <= '1';
790 when "00000000" =>
791 if NMICycle = '1' then
792 -- NMI
793 MCycles <= "011";
794 case to_integer(unsigned(MCycle)) is
795 when 1 =>
796 TStates <= "101";
797 IncDec_16 <= "1111";
798 Set_Addr_To <= aSP;
799 Set_BusB_To <= "1101";
800 when 2 =>
801 TStates <= "100";
802 Write <= '1';
803 IncDec_16 <= "1111";
804 Set_Addr_To <= aSP;
805 Set_BusB_To <= "1100";
806 when 3 =>
807 TStates <= "100";
808 Write <= '1';
809 when others => null;
810 end case;
811 elsif IntCycle = '1' then
812 -- INT (IM 2)
813 MCycles <= "101";
814 case to_integer(unsigned(MCycle)) is
815 when 1 =>
816 LDZ <= '1';
817 TStates <= "101";
818 IncDec_16 <= "1111";
819 Set_Addr_To <= aSP;
820 Set_BusB_To <= "1101";
821 when 2 =>
822 TStates <= "100";
823 Write <= '1';
824 IncDec_16 <= "1111";
825 Set_Addr_To <= aSP;
826 Set_BusB_To <= "1100";
827 when 3 =>
828 TStates <= "100";
829 Write <= '1';
830 when 4 =>
831 Inc_PC <= '1';
832 LDZ <= '1';
833 when 5 =>
834 Jump <= '1';
835 when others => null;
836 end case;
837 else
838 -- NOP
839 end if;
840 when "01110110" =>
841 -- HALT
842 Halt <= '1';
843 when "11110011" =>
844 -- DI
845 SetDI <= '1';
846 when "11111011" =>
847 -- EI
848 SetEI <= '1';
849
850 -- 16 BIT ARITHMETIC GROUP
851 when "00001001"|"00011001"|"00101001"|"00111001" =>
852 -- ADD HL,ss
853 MCycles <= "011";
854 case to_integer(unsigned(MCycle)) is
855 when 2 =>
856 NoRead <= '1';
857 ALU_Op <= "0000";
858 Read_To_Reg <= '1';
859 Save_ALU <= '1';
860 Set_BusA_To(2 downto 0) <= "101";
861 case to_integer(unsigned(IR(5 downto 4))) is
862 when 0|1|2 =>
863 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
864 Set_BusB_To(0) <= '1';
865 when others =>
866 Set_BusB_To <= "1000";
867 end case;
868 TStates <= "100";
869 Arith16 <= '1';
870 when 3 =>
871 NoRead <= '1';
872 Read_To_Reg <= '1';
873 Save_ALU <= '1';
874 ALU_Op <= "0001";
875 Set_BusA_To(2 downto 0) <= "100";
876 case to_integer(unsigned(IR(5 downto 4))) is
877 when 0|1|2 =>
878 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
879 when others =>
880 Set_BusB_To <= "1001";
881 end case;
882 Arith16 <= '1';
883 when others =>
884 end case;
885 when "00000011"|"00010011"|"00100011"|"00110011" =>
886 -- INC ss
887 TStates <= "110";
888 IncDec_16(3 downto 2) <= "01";
889 IncDec_16(1 downto 0) <= DPair;
890 when "00001011"|"00011011"|"00101011"|"00111011" =>
891 -- DEC ss
892 TStates <= "110";
893 IncDec_16(3 downto 2) <= "11";
894 IncDec_16(1 downto 0) <= DPair;
895
896 -- ROTATE AND SHIFT GROUP
897 when "00000111"
898 -- RLCA
899 |"00010111"
900 -- RLA
901 |"00001111"
902 -- RRCA
903 |"00011111" =>
904 -- RRA
905 Set_BusA_To(2 downto 0) <= "111";
906 ALU_Op <= "1000";
907 Read_To_Reg <= '1';
908 Save_ALU <= '1';
909
910 -- JUMP GROUP
911 when "11000011" =>
912 -- JP nn
913 MCycles <= "011";
914 case to_integer(unsigned(MCycle)) is
915 when 2 =>
916 Inc_PC <= '1';
917 LDZ <= '1';
918 when 3 =>
919 Inc_PC <= '1';
920 Jump <= '1';
921 when others => null;
922 end case;
923 when "11000010"|"11001010"|"11010010"|"11011010"|"11100010"|"11101010"|"11110010"|"11111010" =>
924 if IR(5) = '1' and Mode = 3 then
925 case IRB(4 downto 3) is
926 when "00" =>
927 -- LD ($FF00+C),A
928 MCycles <= "010";
929 case to_integer(unsigned(MCycle)) is
930 when 1 =>
931 Set_Addr_To <= aBC;
932 Set_BusB_To <= "0111";
933 when 2 =>
934 Write <= '1';
935 IORQ <= '1';
936 when others =>
937 end case;
938 when "01" =>
939 -- LD (nn),A
940 MCycles <= "100";
941 case to_integer(unsigned(MCycle)) is
942 when 2 =>
943 Inc_PC <= '1';
944 LDZ <= '1';
945 when 3 =>
946 Set_Addr_To <= aZI;
947 Inc_PC <= '1';
948 Set_BusB_To <= "0111";
949 when 4 =>
950 Write <= '1';
951 when others => null;
952 end case;
953 when "10" =>
954 -- LD A,($FF00+C)
955 MCycles <= "010";
956 case to_integer(unsigned(MCycle)) is
957 when 1 =>
958 Set_Addr_To <= aBC;
959 when 2 =>
960 Read_To_Acc <= '1';
961 IORQ <= '1';
962 when others =>
963 end case;
964 when "11" =>
965 -- LD A,(nn)
966 MCycles <= "100";
967 case to_integer(unsigned(MCycle)) is
968 when 2 =>
969 Inc_PC <= '1';
970 LDZ <= '1';
971 when 3 =>
972 Set_Addr_To <= aZI;
973 Inc_PC <= '1';
974 when 4 =>
975 Read_To_Acc <= '1';
976 when others => null;
977 end case;
978 end case;
979 else
980 -- JP cc,nn
981 MCycles <= "011";
982 case to_integer(unsigned(MCycle)) is
983 when 2 =>
984 Inc_PC <= '1';
985 LDZ <= '1';
986 when 3 =>
987 Inc_PC <= '1';
988 if is_cc_true(F, to_bitvector(IR(5 downto 3))) then
989 Jump <= '1';
990 end if;
991 when others => null;
992 end case;
993 end if;
994 when "00011000" =>
995 if Mode /= 2 then
996 -- JR e
997 MCycles <= "011";
998 case to_integer(unsigned(MCycle)) is
999 when 2 =>
1000 Inc_PC <= '1';
1001 when 3 =>
1002 NoRead <= '1';
1003 JumpE <= '1';
1004 TStates <= "101";
1005 when others => null;
1006 end case;
1007 end if;
1008 when "00111000" =>
1009 if Mode /= 2 then
1010 -- JR C,e
1011 MCycles <= "011";
1012 case to_integer(unsigned(MCycle)) is
1013 when 2 =>
1014 Inc_PC <= '1';
1015 if F(Flag_C) = '0' then
1016 MCycles <= "010";
1017 end if;
1018 when 3 =>
1019 NoRead <= '1';
1020 JumpE <= '1';
1021 TStates <= "101";
1022 when others => null;
1023 end case;
1024 end if;
1025 when "00110000" =>
1026 if Mode /= 2 then
1027 -- JR NC,e
1028 MCycles <= "011";
1029 case to_integer(unsigned(MCycle)) is
1030 when 2 =>
1031 Inc_PC <= '1';
1032 if F(Flag_C) = '1' then
1033 MCycles <= "010";
1034 end if;
1035 when 3 =>
1036 NoRead <= '1';
1037 JumpE <= '1';
1038 TStates <= "101";
1039 when others => null;
1040 end case;
1041 end if;
1042 when "00101000" =>
1043 if Mode /= 2 then
1044 -- JR Z,e
1045 MCycles <= "011";
1046 case to_integer(unsigned(MCycle)) is
1047 when 2 =>
1048 Inc_PC <= '1';
1049 if F(Flag_Z) = '0' then
1050 MCycles <= "010";
1051 end if;
1052 when 3 =>
1053 NoRead <= '1';
1054 JumpE <= '1';
1055 TStates <= "101";
1056 when others => null;
1057 end case;
1058 end if;
1059 when "00100000" =>
1060 if Mode /= 2 then
1061 -- JR NZ,e
1062 MCycles <= "011";
1063 case to_integer(unsigned(MCycle)) is
1064 when 2 =>
1065 Inc_PC <= '1';
1066 if F(Flag_Z) = '1' then
1067 MCycles <= "010";
1068 end if;
1069 when 3 =>
1070 NoRead <= '1';
1071 JumpE <= '1';
1072 TStates <= "101";
1073 when others => null;
1074 end case;
1075 end if;
1076 when "11101001" =>
1077 -- JP (HL)
1078 JumpXY <= '1';
1079 when "00010000" =>
1080 if Mode = 3 then
1081 I_DJNZ <= '1';
1082 elsif Mode < 2 then
1083 -- DJNZ,e
1084 MCycles <= "011";
1085 case to_integer(unsigned(MCycle)) is
1086 when 1 =>
1087 TStates <= "101";
1088 I_DJNZ <= '1';
1089 Set_BusB_To <= "1010";
1090 Set_BusA_To(2 downto 0) <= "000";
1091 Read_To_Reg <= '1';
1092 Save_ALU <= '1';
1093 ALU_Op <= "0010";
1094 when 2 =>
1095 I_DJNZ <= '1';
1096 Inc_PC <= '1';
1097 when 3 =>
1098 NoRead <= '1';
1099 JumpE <= '1';
1100 TStates <= "101";
1101 when others => null;
1102 end case;
1103 end if;
1104
1105 -- CALL AND RETURN GROUP
1106 when "11001101" =>
1107 -- CALL nn
1108 MCycles <= "101";
1109 case to_integer(unsigned(MCycle)) is
1110 when 2 =>
1111 Inc_PC <= '1';
1112 LDZ <= '1';
1113 when 3 =>
1114 IncDec_16 <= "1111";
1115 Inc_PC <= '1';
1116 TStates <= "100";
1117 Set_Addr_To <= aSP;
1118 LDW <= '1';
1119 Set_BusB_To <= "1101";
1120 when 4 =>
1121 Write <= '1';
1122 IncDec_16 <= "1111";
1123 Set_Addr_To <= aSP;
1124 Set_BusB_To <= "1100";
1125 when 5 =>
1126 Write <= '1';
1127 Call <= '1';
1128 when others => null;
1129 end case;
1130 when "11000100"|"11001100"|"11010100"|"11011100"|"11100100"|"11101100"|"11110100"|"11111100" =>
1131 if IR(5) = '0' or Mode /= 3 then
1132 -- CALL cc,nn
1133 MCycles <= "101";
1134 case to_integer(unsigned(MCycle)) is
1135 when 2 =>
1136 Inc_PC <= '1';
1137 LDZ <= '1';
1138 when 3 =>
1139 Inc_PC <= '1';
1140 LDW <= '1';
1141 if is_cc_true(F, to_bitvector(IR(5 downto 3))) then
1142 IncDec_16 <= "1111";
1143 Set_Addr_TO <= aSP;
1144 TStates <= "100";
1145 Set_BusB_To <= "1101";
1146 else
1147 MCycles <= "011";
1148 end if;
1149 when 4 =>
1150 Write <= '1';
1151 IncDec_16 <= "1111";
1152 Set_Addr_To <= aSP;
1153 Set_BusB_To <= "1100";
1154 when 5 =>
1155 Write <= '1';
1156 Call <= '1';
1157 when others => null;
1158 end case;
1159 end if;
1160 when "11001001" =>
1161 -- RET
1162 MCycles <= "011";
1163 case to_integer(unsigned(MCycle)) is
1164 when 1 =>
1165 TStates <= "101";
1166 Set_Addr_TO <= aSP;
1167 when 2 =>
1168 IncDec_16 <= "0111";
1169 Set_Addr_To <= aSP;
1170 LDZ <= '1';
1171 when 3 =>
1172 Jump <= '1';
1173 IncDec_16 <= "0111";
1174 when others => null;
1175 end case;
1176 when "11000000"|"11001000"|"11010000"|"11011000"|"11100000"|"11101000"|"11110000"|"11111000" =>
1177 if IR(5) = '1' and Mode = 3 then
1178 case IRB(4 downto 3) is
1179 when "00" =>
1180 -- LD ($FF00+nn),A
1181 MCycles <= "011";
1182 case to_integer(unsigned(MCycle)) is
1183 when 2 =>
1184 Inc_PC <= '1';
1185 Set_Addr_To <= aIOA;
1186 Set_BusB_To <= "0111";
1187 when 3 =>
1188 Write <= '1';
1189 when others => null;
1190 end case;
1191 when "01" =>
1192 -- ADD SP,n
1193 MCycles <= "011";
1194 case to_integer(unsigned(MCycle)) is
1195 when 2 =>
1196 ALU_Op <= "0000";
1197 Inc_PC <= '1';
1198 Read_To_Reg <= '1';
1199 Save_ALU <= '1';
1200 Set_BusA_To <= "1000";
1201 Set_BusB_To <= "0110";
1202 when 3 =>
1203 NoRead <= '1';
1204 Read_To_Reg <= '1';
1205 Save_ALU <= '1';
1206 ALU_Op <= "0001";
1207 Set_BusA_To <= "1001";
1208 Set_BusB_To <= "1110"; -- Incorrect unsigned !!!!!!!!!!!!!!!!!!!!!
1209 when others =>
1210 end case;
1211 when "10" =>
1212 -- LD A,($FF00+nn)
1213 MCycles <= "011";
1214 case to_integer(unsigned(MCycle)) is
1215 when 2 =>
1216 Inc_PC <= '1';
1217 Set_Addr_To <= aIOA;
1218 when 3 =>
1219 Read_To_Acc <= '1';
1220 when others => null;
1221 end case;
1222 when "11" =>
1223 -- LD HL,SP+n -- Not correct !!!!!!!!!!!!!!!!!!!
1224 MCycles <= "101";
1225 case to_integer(unsigned(MCycle)) is
1226 when 2 =>
1227 Inc_PC <= '1';
1228 LDZ <= '1';
1229 when 3 =>
1230 Set_Addr_To <= aZI;
1231 Inc_PC <= '1';
1232 LDW <= '1';
1233 when 4 =>
1234 Set_BusA_To(2 downto 0) <= "101"; -- L
1235 Read_To_Reg <= '1';
1236 Inc_WZ <= '1';
1237 Set_Addr_To <= aZI;
1238 when 5 =>
1239 Set_BusA_To(2 downto 0) <= "100"; -- H
1240 Read_To_Reg <= '1';
1241 when others => null;
1242 end case;
1243 end case;
1244 else
1245 -- RET cc
1246 MCycles <= "011";
1247 case to_integer(unsigned(MCycle)) is
1248 when 1 =>
1249 if is_cc_true(F, to_bitvector(IR(5 downto 3))) then
1250 Set_Addr_TO <= aSP;
1251 else
1252 MCycles <= "001";
1253 end if;
1254 TStates <= "101";
1255 when 2 =>
1256 IncDec_16 <= "0111";
1257 Set_Addr_To <= aSP;
1258 LDZ <= '1';
1259 when 3 =>
1260 Jump <= '1';
1261 IncDec_16 <= "0111";
1262 when others => null;
1263 end case;
1264 end if;
1265 when "11000111"|"11001111"|"11010111"|"11011111"|"11100111"|"11101111"|"11110111"|"11111111" =>
1266 -- RST p
1267 MCycles <= "011";
1268 case to_integer(unsigned(MCycle)) is
1269 when 1 =>
1270 TStates <= "101";
1271 IncDec_16 <= "1111";
1272 Set_Addr_To <= aSP;
1273 Set_BusB_To <= "1101";
1274 when 2 =>
1275 Write <= '1';
1276 IncDec_16 <= "1111";
1277 Set_Addr_To <= aSP;
1278 Set_BusB_To <= "1100";
1279 when 3 =>
1280 Write <= '1';
1281 RstP <= '1';
1282 when others => null;
1283 end case;
1284
1285 -- INPUT AND OUTPUT GROUP
1286 when "11011011" =>
1287 if Mode /= 3 then
1288 -- IN A,(n)
1289 MCycles <= "011";
1290 case to_integer(unsigned(MCycle)) is
1291 when 2 =>
1292 Inc_PC <= '1';
1293 Set_Addr_To <= aIOA;
1294 when 3 =>
1295 Read_To_Acc <= '1';
1296 IORQ <= '1';
1297 when others => null;
1298 end case;
1299 end if;
1300 when "11010011" =>
1301 if Mode /= 3 then
1302 -- OUT (n),A
1303 MCycles <= "011";
1304 case to_integer(unsigned(MCycle)) is
1305 when 2 =>
1306 Inc_PC <= '1';
1307 Set_Addr_To <= aIOA;
1308 Set_BusB_To <= "0111";
1309 when 3 =>
1310 Write <= '1';
1311 IORQ <= '1';
1312 when others => null;
1313 end case;
1314 end if;
1315
1316 ------------------------------------------------------------------------------
1317 ------------------------------------------------------------------------------
1318 -- MULTIBYTE INSTRUCTIONS
1319 ------------------------------------------------------------------------------
1320 ------------------------------------------------------------------------------
1321
1322 when "11001011" =>
1323 if Mode /= 2 then
1324 Prefix <= "01";
1325 end if;
1326
1327 when "11101101" =>
1328 if Mode < 2 then
1329 Prefix <= "10";
1330 end if;
1331
1332 when "11011101"|"11111101" =>
1333 if Mode < 2 then
1334 Prefix <= "11";
1335 end if;
1336
1337 end case;
1338
1339 when "01" =>
1340
1341 ------------------------------------------------------------------------------
1342 --
1343 -- CB prefixed instructions
1344 --
1345 ------------------------------------------------------------------------------
1346
1347 Set_BusA_To(2 downto 0) <= IR(2 downto 0);
1348 Set_BusB_To(2 downto 0) <= IR(2 downto 0);
1349
1350 case IRB is
1351 when "00000000"|"00000001"|"00000010"|"00000011"|"00000100"|"00000101"|"00000111"
1352 |"00010000"|"00010001"|"00010010"|"00010011"|"00010100"|"00010101"|"00010111"
1353 |"00001000"|"00001001"|"00001010"|"00001011"|"00001100"|"00001101"|"00001111"
1354 |"00011000"|"00011001"|"00011010"|"00011011"|"00011100"|"00011101"|"00011111"
1355 |"00100000"|"00100001"|"00100010"|"00100011"|"00100100"|"00100101"|"00100111"
1356 |"00101000"|"00101001"|"00101010"|"00101011"|"00101100"|"00101101"|"00101111"
1357 |"00110000"|"00110001"|"00110010"|"00110011"|"00110100"|"00110101"|"00110111"
1358 |"00111000"|"00111001"|"00111010"|"00111011"|"00111100"|"00111101"|"00111111" =>
1359 -- RLC r
1360 -- RL r
1361 -- RRC r
1362 -- RR r
1363 -- SLA r
1364 -- SRA r
1365 -- SRL r
1366 -- SLL r (Undocumented) / SWAP r
1367 if MCycle = "001" then
1368 ALU_Op <= "1000";
1369 Read_To_Reg <= '1';
1370 Save_ALU <= '1';
1371 end if;
1372 when "00000110"|"00010110"|"00001110"|"00011110"|"00101110"|"00111110"|"00100110"|"00110110" =>
1373 -- RLC (HL)
1374 -- RL (HL)
1375 -- RRC (HL)
1376 -- RR (HL)
1377 -- SRA (HL)
1378 -- SRL (HL)
1379 -- SLA (HL)
1380 -- SLL (HL) (Undocumented) / SWAP (HL)
1381 MCycles <= "011";
1382 case to_integer(unsigned(MCycle)) is
1383 when 1 | 7 =>
1384 Set_Addr_To <= aXY;
1385 when 2 =>
1386 ALU_Op <= "1000";
1387 Read_To_Reg <= '1';
1388 Save_ALU <= '1';
1389 Set_Addr_To <= aXY;
1390 TStates <= "100";
1391 when 3 =>
1392 Write <= '1';
1393 when others =>
1394 end case;
1395 when "01000000"|"01000001"|"01000010"|"01000011"|"01000100"|"01000101"|"01000111"
1396 |"01001000"|"01001001"|"01001010"|"01001011"|"01001100"|"01001101"|"01001111"
1397 |"01010000"|"01010001"|"01010010"|"01010011"|"01010100"|"01010101"|"01010111"
1398 |"01011000"|"01011001"|"01011010"|"01011011"|"01011100"|"01011101"|"01011111"
1399 |"01100000"|"01100001"|"01100010"|"01100011"|"01100100"|"01100101"|"01100111"
1400 |"01101000"|"01101001"|"01101010"|"01101011"|"01101100"|"01101101"|"01101111"
1401 |"01110000"|"01110001"|"01110010"|"01110011"|"01110100"|"01110101"|"01110111"
1402 |"01111000"|"01111001"|"01111010"|"01111011"|"01111100"|"01111101"|"01111111" =>
1403 -- BIT b,r
1404 if MCycle = "001" then
1405 Set_BusB_To(2 downto 0) <= IR(2 downto 0);
1406 ALU_Op <= "1001";
1407 end if;
1408 when "01000110"|"01001110"|"01010110"|"01011110"|"01100110"|"01101110"|"01110110"|"01111110" =>
1409 -- BIT b,(HL)
1410 MCycles <= "010";
1411 case to_integer(unsigned(MCycle)) is
1412 when 1 | 7=>
1413 Set_Addr_To <= aXY;
1414 when 2 =>
1415 ALU_Op <= "1001";
1416 TStates <= "100";
1417 when others => null;
1418 end case;
1419 when "11000000"|"11000001"|"11000010"|"11000011"|"11000100"|"11000101"|"11000111"
1420 |"11001000"|"11001001"|"11001010"|"11001011"|"11001100"|"11001101"|"11001111"
1421 |"11010000"|"11010001"|"11010010"|"11010011"|"11010100"|"11010101"|"11010111"
1422 |"11011000"|"11011001"|"11011010"|"11011011"|"11011100"|"11011101"|"11011111"
1423 |"11100000"|"11100001"|"11100010"|"11100011"|"11100100"|"11100101"|"11100111"
1424 |"11101000"|"11101001"|"11101010"|"11101011"|"11101100"|"11101101"|"11101111"
1425 |"11110000"|"11110001"|"11110010"|"11110011"|"11110100"|"11110101"|"11110111"
1426 |"11111000"|"11111001"|"11111010"|"11111011"|"11111100"|"11111101"|"11111111" =>
1427 -- SET b,r
1428 if MCycle = "001" then
1429 ALU_Op <= "1010";
1430 Read_To_Reg <= '1';
1431 Save_ALU <= '1';
1432 end if;
1433 when "11000110"|"11001110"|"11010110"|"11011110"|"11100110"|"11101110"|"11110110"|"11111110" =>
1434 -- SET b,(HL)
1435 MCycles <= "011";
1436 case to_integer(unsigned(MCycle)) is
1437 when 1 | 7=>
1438 Set_Addr_To <= aXY;
1439 when 2 =>
1440 ALU_Op <= "1010";
1441 Read_To_Reg <= '1';
1442 Save_ALU <= '1';
1443 Set_Addr_To <= aXY;
1444 TStates <= "100";
1445 when 3 =>
1446 Write <= '1';
1447 when others => null;
1448 end case;
1449 when "10000000"|"10000001"|"10000010"|"10000011"|"10000100"|"10000101"|"10000111"
1450 |"10001000"|"10001001"|"10001010"|"10001011"|"10001100"|"10001101"|"10001111"
1451 |"10010000"|"10010001"|"10010010"|"10010011"|"10010100"|"10010101"|"10010111"
1452 |"10011000"|"10011001"|"10011010"|"10011011"|"10011100"|"10011101"|"10011111"
1453 |"10100000"|"10100001"|"10100010"|"10100011"|"10100100"|"10100101"|"10100111"
1454 |"10101000"|"10101001"|"10101010"|"10101011"|"10101100"|"10101101"|"10101111"
1455 |"10110000"|"10110001"|"10110010"|"10110011"|"10110100"|"10110101"|"10110111"
1456 |"10111000"|"10111001"|"10111010"|"10111011"|"10111100"|"10111101"|"10111111" =>
1457 -- RES b,r
1458 if MCycle = "001" then
1459 ALU_Op <= "1011";
1460 Read_To_Reg <= '1';
1461 Save_ALU <= '1';
1462 end if;
1463 when "10000110"|"10001110"|"10010110"|"10011110"|"10100110"|"10101110"|"10110110"|"10111110" =>
1464 -- RES b,(HL)
1465 MCycles <= "011";
1466 case to_integer(unsigned(MCycle)) is
1467 when 1 | 7 =>
1468 Set_Addr_To <= aXY;
1469 when 2 =>
1470 ALU_Op <= "1011";
1471 Read_To_Reg <= '1';
1472 Save_ALU <= '1';
1473 Set_Addr_To <= aXY;
1474 TStates <= "100";
1475 when 3 =>
1476 Write <= '1';
1477 when others => null;
1478 end case;
1479 end case;
1480
1481 when others =>
1482
1483 ------------------------------------------------------------------------------
1484 --
1485 -- ED prefixed instructions
1486 --
1487 ------------------------------------------------------------------------------
1488
1489 case IRB is
1490 when "00000000"|"00000001"|"00000010"|"00000011"|"00000100"|"00000101"|"00000110"|"00000111"
1491 |"00001000"|"00001001"|"00001010"|"00001011"|"00001100"|"00001101"|"00001110"|"00001111"
1492 |"00010000"|"00010001"|"00010010"|"00010011"|"00010100"|"00010101"|"00010110"|"00010111"
1493 |"00011000"|"00011001"|"00011010"|"00011011"|"00011100"|"00011101"|"00011110"|"00011111"
1494 |"00100000"|"00100001"|"00100010"|"00100011"|"00100100"|"00100101"|"00100110"|"00100111"
1495 |"00101000"|"00101001"|"00101010"|"00101011"|"00101100"|"00101101"|"00101110"|"00101111"
1496 |"00110000"|"00110001"|"00110010"|"00110011"|"00110100"|"00110101"|"00110110"|"00110111"
1497 |"00111000"|"00111001"|"00111010"|"00111011"|"00111100"|"00111101"|"00111110"|"00111111"
1498
1499
1500 |"10000000"|"10000001"|"10000010"|"10000011"|"10000100"|"10000101"|"10000110"|"10000111"
1501 |"10001000"|"10001001"|"10001010"|"10001011"|"10001100"|"10001101"|"10001110"|"10001111"
1502 |"10010000"|"10010001"|"10010010"|"10010011"|"10010100"|"10010101"|"10010110"|"10010111"
1503 |"10011000"|"10011001"|"10011010"|"10011011"|"10011100"|"10011101"|"10011110"|"10011111"
1504 | "10100100"|"10100101"|"10100110"|"10100111"
1505 | "10101100"|"10101101"|"10101110"|"10101111"
1506 | "10110100"|"10110101"|"10110110"|"10110111"
1507 | "10111100"|"10111101"|"10111110"|"10111111"
1508 |"11000000"|"11000001"|"11000010"|"11000011"|"11000100"|"11000101"|"11000110"|"11000111"
1509 |"11001000"|"11001001"|"11001010"|"11001011"|"11001100"|"11001101"|"11001110"|"11001111"
1510 |"11010000"|"11010001"|"11010010"|"11010011"|"11010100"|"11010101"|"11010110"|"11010111"
1511 |"11011000"|"11011001"|"11011010"|"11011011"|"11011100"|"11011101"|"11011110"|"11011111"
1512 |"11100000"|"11100001"|"11100010"|"11100011"|"11100100"|"11100101"|"11100110"|"11100111"
1513 |"11101000"|"11101001"|"11101010"|"11101011"|"11101100"|"11101101"|"11101110"|"11101111"
1514 |"11110000"|"11110001"|"11110010"|"11110011"|"11110100"|"11110101"|"11110110"|"11110111"
1515 |"11111000"|"11111001"|"11111010"|"11111011"|"11111100"|"11111101"|"11111110"|"11111111" =>
1516 null; -- NOP, undocumented
1517 when "01111110"|"01111111" =>
1518 -- NOP, undocumented
1519 null;
1520 -- 8 BIT LOAD GROUP
1521 when "01010111" =>
1522 -- LD A,I
1523 Special_LD <= "100";
1524 TStates <= "101";
1525 when "01011111" =>
1526 -- LD A,R
1527 Special_LD <= "101";
1528 TStates <= "101";
1529 when "01000111" =>
1530 -- LD I,A
1531 Special_LD <= "110";
1532 TStates <= "101";
1533 when "01001111" =>
1534 -- LD R,A
1535 Special_LD <= "111";
1536 TStates <= "101";
1537 -- 16 BIT LOAD GROUP
1538 when "01001011"|"01011011"|"01101011"|"01111011" =>
1539 -- LD dd,(nn)
1540 MCycles <= "101";
1541 case to_integer(unsigned(MCycle)) is
1542 when 2 =>
1543 Inc_PC <= '1';
1544 LDZ <= '1';
1545 when 3 =>
1546 Set_Addr_To <= aZI;
1547 Inc_PC <= '1';
1548 LDW <= '1';
1549 when 4 =>
1550 Read_To_Reg <= '1';
1551 if IR(5 downto 4) = "11" then
1552 Set_BusA_To <= "1000";
1553 else
1554 Set_BusA_To(2 downto 1) <= IR(5 downto 4);
1555 Set_BusA_To(0) <= '1';
1556 end if;
1557 Inc_WZ <= '1';
1558 Set_Addr_To <= aZI;
1559 when 5 =>
1560 Read_To_Reg <= '1';
1561 if IR(5 downto 4) = "11" then
1562 Set_BusA_To <= "1001";
1563 else
1564 Set_BusA_To(2 downto 1) <= IR(5 downto 4);
1565 Set_BusA_To(0) <= '0';
1566 end if;
1567 when others => null;
1568 end case;
1569 when "01000011"|"01010011"|"01100011"|"01110011" =>
1570 -- LD (nn),dd
1571 MCycles <= "101";
1572 case to_integer(unsigned(MCycle)) is
1573 when 2 =>
1574 Inc_PC <= '1';
1575 LDZ <= '1';
1576 when 3 =>
1577 Set_Addr_To <= aZI;
1578 Inc_PC <= '1';
1579 LDW <= '1';
1580 if IR(5 downto 4) = "11" then
1581 Set_BusB_To <= "1000";
1582 else
1583 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1584 Set_BusB_To(0) <= '1';
1585 Set_BusB_To(3) <= '0';
1586 end if;
1587 when 4 =>
1588 Inc_WZ <= '1';
1589 Set_Addr_To <= aZI;
1590 Write <= '1';
1591 if IR(5 downto 4) = "11" then
1592 Set_BusB_To <= "1001";
1593 else
1594 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1595 Set_BusB_To(0) <= '0';
1596 Set_BusB_To(3) <= '0';
1597 end if;
1598 when 5 =>
1599 Write <= '1';
1600 when others => null;
1601 end case;
1602 when "10100000" | "10101000" | "10110000" | "10111000" =>
1603 -- LDI, LDD, LDIR, LDDR
1604 MCycles <= "100";
1605 case to_integer(unsigned(MCycle)) is
1606 when 1 =>
1607 Set_Addr_To <= aXY;
1608 IncDec_16 <= "1100"; -- BC
1609 when 2 =>
1610 Set_BusB_To <= "0110";
1611 Set_BusA_To(2 downto 0) <= "111";
1612 ALU_Op <= "0000";
1613 Set_Addr_To <= aDE;
1614 if IR(3) = '0' then
1615 IncDec_16 <= "0110"; -- IX
1616 else
1617 IncDec_16 <= "1110";
1618 end if;
1619 when 3 =>
1620 I_BT <= '1';
1621 TStates <= "101";
1622 Write <= '1';
1623 if IR(3) = '0' then
1624 IncDec_16 <= "0101"; -- DE
1625 else
1626 IncDec_16 <= "1101";
1627 end if;
1628 when 4 =>
1629 NoRead <= '1';
1630 TStates <= "101";
1631 when others => null;
1632 end case;
1633 when "10100001" | "10101001" | "10110001" | "10111001" =>
1634 -- CPI, CPD, CPIR, CPDR
1635 MCycles <= "100";
1636 case to_integer(unsigned(MCycle)) is
1637 when 1 =>
1638 Set_Addr_To <= aXY;
1639 IncDec_16 <= "1100"; -- BC
1640 when 2 =>
1641 Set_BusB_To <= "0110";
1642 Set_BusA_To(2 downto 0) <= "111";
1643 ALU_Op <= "0111";
1644 Save_ALU <= '1';
1645 PreserveC <= '1';
1646 if IR(3) = '0' then
1647 IncDec_16 <= "0110";
1648 else
1649 IncDec_16 <= "1110";
1650 end if;
1651 when 3 =>
1652 NoRead <= '1';
1653 I_BC <= '1';
1654 TStates <= "101";
1655 when 4 =>
1656 NoRead <= '1';
1657 TStates <= "101";
1658 when others => null;
1659 end case;
1660 when "01000100"|"01001100"|"01010100"|"01011100"|"01100100"|"01101100"|"01110100"|"01111100" =>
1661 -- NEG
1662 Alu_OP <= "0010";
1663 Set_BusB_To <= "0111";
1664 Set_BusA_To <= "1010";
1665 Read_To_Acc <= '1';
1666 Save_ALU <= '1';
1667 when "01000110"|"01001110"|"01100110"|"01101110" =>
1668 -- IM 0
1669 IMode <= "00";
1670 when "01010110"|"01110110" =>
1671 -- IM 1
1672 IMode <= "01";
1673 when "01011110"|"01110111" =>
1674 -- IM 2
1675 IMode <= "10";
1676 -- 16 bit arithmetic
1677 when "01001010"|"01011010"|"01101010"|"01111010" =>
1678 -- ADC HL,ss
1679 MCycles <= "011";
1680 case to_integer(unsigned(MCycle)) is
1681 when 2 =>
1682 NoRead <= '1';
1683 ALU_Op <= "0001";
1684 Read_To_Reg <= '1';
1685 Save_ALU <= '1';
1686 Set_BusA_To(2 downto 0) <= "101";
1687 case to_integer(unsigned(IR(5 downto 4))) is
1688 when 0|1|2 =>
1689 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1690 Set_BusB_To(0) <= '1';
1691 when others =>
1692 Set_BusB_To <= "1000";
1693 end case;
1694 TStates <= "100";
1695 when 3 =>
1696 NoRead <= '1';
1697 Read_To_Reg <= '1';
1698 Save_ALU <= '1';
1699 ALU_Op <= "0001";
1700 Set_BusA_To(2 downto 0) <= "100";
1701 case to_integer(unsigned(IR(5 downto 4))) is
1702 when 0|1|2 =>
1703 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1704 Set_BusB_To(0) <= '0';
1705 when others =>
1706 Set_BusB_To <= "1001";
1707 end case;
1708 when others =>
1709 end case;
1710 when "01000010"|"01010010"|"01100010"|"01110010" =>
1711 -- SBC HL,ss
1712 MCycles <= "011";
1713 case to_integer(unsigned(MCycle)) is
1714 when 2 =>
1715 NoRead <= '1';
1716 ALU_Op <= "0011";
1717 Read_To_Reg <= '1';
1718 Save_ALU <= '1';
1719 Set_BusA_To(2 downto 0) <= "101";
1720 case to_integer(unsigned(IR(5 downto 4))) is
1721 when 0|1|2 =>
1722 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1723 Set_BusB_To(0) <= '1';
1724 when others =>
1725 Set_BusB_To <= "1000";
1726 end case;
1727 TStates <= "100";
1728 when 3 =>
1729 NoRead <= '1';
1730 ALU_Op <= "0011";
1731 Read_To_Reg <= '1';
1732 Save_ALU <= '1';
1733 Set_BusA_To(2 downto 0) <= "100";
1734 case to_integer(unsigned(IR(5 downto 4))) is
1735 when 0|1|2 =>
1736 Set_BusB_To(2 downto 1) <= IR(5 downto 4);
1737 when others =>
1738 Set_BusB_To <= "1001";
1739 end case;
1740 when others =>
1741 end case;
1742 when "01101111" =>
1743 -- RLD
1744 MCycles <= "100";
1745 case to_integer(unsigned(MCycle)) is
1746 when 2 =>
1747 NoRead <= '1';
1748 Set_Addr_To <= aXY;
1749 when 3 =>
1750 Read_To_Reg <= '1';
1751 Set_BusB_To(2 downto 0) <= "110";
1752 Set_BusA_To(2 downto 0) <= "111";
1753 ALU_Op <= "1101";
1754 TStates <= "100";
1755 Set_Addr_To <= aXY;
1756 Save_ALU <= '1';
1757 when 4 =>
1758 I_RLD <= '1';
1759 Write <= '1';
1760 when others =>
1761 end case;
1762 when "01100111" =>
1763 -- RRD
1764 MCycles <= "100";
1765 case to_integer(unsigned(MCycle)) is
1766 when 2 =>
1767 Set_Addr_To <= aXY;
1768 when 3 =>
1769 Read_To_Reg <= '1';
1770 Set_BusB_To(2 downto 0) <= "110";
1771 Set_BusA_To(2 downto 0) <= "111";
1772 ALU_Op <= "1110";
1773 TStates <= "100";
1774 Set_Addr_To <= aXY;
1775 Save_ALU <= '1';
1776 when 4 =>
1777 I_RRD <= '1';
1778 Write <= '1';
1779 when others =>
1780 end case;
1781 when "01000101"|"01001101"|"01010101"|"01011101"|"01100101"|"01101101"|"01110101"|"01111101" =>
1782 -- RETI, RETN
1783 MCycles <= "011";
1784 case to_integer(unsigned(MCycle)) is
1785 when 1 =>
1786 Set_Addr_TO <= aSP;
1787 when 2 =>
1788 IncDec_16 <= "0111";
1789 Set_Addr_To <= aSP;
1790 LDZ <= '1';
1791 when 3 =>
1792 Jump <= '1';
1793 IncDec_16 <= "0111";
1794 I_RETN <= '1';
1795 when others => null;
1796 end case;
1797 when "01000000"|"01001000"|"01010000"|"01011000"|"01100000"|"01101000"|"01110000"|"01111000" =>
1798 -- IN r,(C)
1799 MCycles <= "010";
1800 case to_integer(unsigned(MCycle)) is
1801 when 1 =>
1802 Set_Addr_To <= aBC;
1803 when 2 =>
1804 IORQ <= '1';
1805 if IR(5 downto 3) /= "110" then
1806 Read_To_Reg <= '1';
1807 Set_BusA_To(2 downto 0) <= IR(5 downto 3);
1808 end if;
1809 I_INRC <= '1';
1810 when others =>
1811 end case;
1812 when "01000001"|"01001001"|"01010001"|"01011001"|"01100001"|"01101001"|"01110001"|"01111001" =>
1813 -- OUT (C),r
1814 -- OUT (C),0
1815 MCycles <= "010";
1816 case to_integer(unsigned(MCycle)) is
1817 when 1 =>
1818 Set_Addr_To <= aBC;
1819 Set_BusB_To(2 downto 0) <= IR(5 downto 3);
1820 if IR(5 downto 3) = "110" then
1821 Set_BusB_To(3) <= '1';
1822 end if;
1823 when 2 =>
1824 Write <= '1';
1825 IORQ <= '1';
1826 when others =>
1827 end case;
1828 when "10100010" | "10101010" | "10110010" | "10111010" =>
1829 -- INI, IND, INIR, INDR
1830 -- note B is decremented AFTER being put on the bus
1831 MCycles <= "100";
1832 case to_integer(unsigned(MCycle)) is
1833 when 1 =>
1834 Set_Addr_To <= aBC;
1835 Set_BusB_To <= "1010";
1836 Set_BusA_To <= "0000";
1837 Read_To_Reg <= '1';
1838 Save_ALU <= '1';
1839 ALU_Op <= "0010";
1840 when 2 =>
1841 IORQ <= '1';
1842 Set_BusB_To <= "0110";
1843 Set_Addr_To <= aXY;
1844 when 3 =>
1845 if IR(3) = '0' then
1846 --IncDec_16 <= "0010";
1847 IncDec_16 <= "0110";
1848 else
1849 --IncDec_16 <= "1010";
1850 IncDec_16 <= "1110";
1851 end if;
1852 TStates <= "100";
1853 Write <= '1';
1854 I_BTR <= '1';
1855 when 4 =>
1856 NoRead <= '1';
1857 TStates <= "101";
1858 when others => null;
1859 end case;
1860 when "10100011" | "10101011" | "10110011" | "10111011" =>
1861 -- OUTI, OUTD, OTIR, OTDR
1862 -- note B is decremented BEFORE being put on the bus.
1863 -- mikej fix for hl inc
1864 MCycles <= "100";
1865 case to_integer(unsigned(MCycle)) is
1866 when 1 =>
1867 TStates <= "101";
1868 Set_Addr_To <= aXY;
1869 Set_BusB_To <= "1010";
1870 Set_BusA_To <= "0000";
1871 Read_To_Reg <= '1';
1872 Save_ALU <= '1';
1873 ALU_Op <= "0010";
1874 when 2 =>
1875 Set_BusB_To <= "0110";
1876 Set_Addr_To <= aBC;
1877 when 3 =>
1878 if IR(3) = '0' then
1879 IncDec_16 <= "0110"; -- mikej
1880 else
1881 IncDec_16 <= "1110"; -- mikej
1882 end if;
1883 IORQ <= '1';
1884 Write <= '1';
1885 I_BTR <= '1';
1886 when 4 =>
1887 NoRead <= '1';
1888 TStates <= "101";
1889 when others => null;
1890 end case;
1891 end case;
1892
1893 end case;
1894
1895 if Mode = 1 then
1896 if MCycle = "001" then
1897 -- TStates <= "100";
1898 else
1899 TStates <= "011";
1900 end if;
1901 end if;
1902
1903 if Mode = 3 then
1904 if MCycle = "001" then
1905 -- TStates <= "100";
1906 else
1907 TStates <= "100";
1908 end if;
1909 end if;
1910
1911 if Mode < 2 then
1912 if MCycle = "110" then
1913 Inc_PC <= '1';
1914 if Mode = 1 then
1915 Set_Addr_To <= aXY;
1916 TStates <= "100";
1917 Set_BusB_To(2 downto 0) <= SSS;
1918 Set_BusB_To(3) <= '0';
1919 end if;
1920 if IRB = "00110110" or IRB = "11001011" then
1921 Set_Addr_To <= aNone;
1922 end if;
1923 end if;
1924 if MCycle = "111" then
1925 if Mode = 0 then
1926 TStates <= "101";
1927 end if;
1928 if ISet /= "01" then
1929 Set_Addr_To <= aXY;
1930 end if;
1931 Set_BusB_To(2 downto 0) <= SSS;
1932 Set_BusB_To(3) <= '0';
1933 if IRB = "00110110" or ISet = "01" then
1934 -- LD (HL),n
1935 Inc_PC <= '1';
1936 else
1937 NoRead <= '1';
1938 end if;
1939 end if;
1940 end if;
1941
1942 end process;
1943
1944 end;
Arcade Games for FPGAs (currently only galaxian)
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