1 // snes_spc 0.9.0. http://www.slack.net/~ant/
2
3 /* Copyright (C) 2004-2007 Shay Green. This module is free software; you
4 can redistribute it and/or modify it under the terms of the GNU Lesser
5 General Public License as published by the Free Software Foundation; either
6 version 2.1 of the License, or (at your option) any later version. This
7 module is distributed in the hope that it will be useful, but WITHOUT ANY
8 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
10 details. You should have received a copy of the GNU Lesser General Public
11 License along with this module; if not, write to the Free Software Foundation,
12 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
13
14 //// Memory access
15
16 #if SPC_MORE_ACCURACY
17 #define SUSPICIOUS_OPCODE( name ) ((void) 0)
18 #else
19 #define SUSPICIOUS_OPCODE( name ) dprintf( "SPC: suspicious opcode: " name "\n" )
20 #endif
21
22 #define CPU_READ( time, offset, addr )\
23 cpu_read( addr, time + offset )
24
25 #define CPU_WRITE( time, offset, addr, data )\
26 cpu_write( data, addr, time + offset )
27
28 #if SPC_MORE_ACCURACY
29 #define CPU_READ_TIMER( time, offset, addr, out )\
30 { out = CPU_READ( time, offset, addr ); }
31
32 #else
33 // timers are by far the most common thing read from dp
34 #define CPU_READ_TIMER( time, offset, addr_, out )\
35 {\
36 rel_time_t adj_time = time + offset;\
37 int dp_addr = addr_;\
38 int ti = dp_addr - (r_t0out + 0xF0);\
39 if ( (unsigned) ti < timer_count )\
40 {\
41 Timer* t = &m.timers [ti];\
42 if ( adj_time >= t->next_time )\
43 t = run_timer_( t, adj_time );\
44 out = t->counter;\
45 t->counter = 0;\
46 }\
47 else\
48 {\
49 out = ram [dp_addr];\
50 int i = dp_addr - 0xF0;\
51 if ( (unsigned) i < 0x10 )\
52 out = cpu_read_smp_reg( i, adj_time );\
53 }\
54 }
55 #endif
56
57 #define TIME_ADJ( n ) (n)
58
59 #define READ_TIMER( time, addr, out ) CPU_READ_TIMER( rel_time, TIME_ADJ(time), (addr), out )
60 #define READ( time, addr ) CPU_READ ( rel_time, TIME_ADJ(time), (addr) )
61 #define WRITE( time, addr, data ) CPU_WRITE( rel_time, TIME_ADJ(time), (addr), (data) )
62
63 #define DP_ADDR( addr ) (dp + (addr))
64
65 #define READ_DP_TIMER( time, addr, out ) CPU_READ_TIMER( rel_time, TIME_ADJ(time), DP_ADDR( addr ), out )
66 #define READ_DP( time, addr ) READ ( time, DP_ADDR( addr ) )
67 #define WRITE_DP( time, addr, data ) WRITE( time, DP_ADDR( addr ), data )
68
69 #define READ_PROG16( addr ) GET_LE16( ram + (addr) )
70
71 #define SET_PC( n ) (pc = ram + (n))
72 #define GET_PC() (int(pc - ram))
73 #define READ_PC( pc ) (*(pc))
74 #define READ_PC16( pc ) GET_LE16( pc )
75
76 // TODO: remove non-wrapping versions?
77 #define SPC_NO_SP_WRAPAROUND 0
78
79 #define SET_SP( v ) (sp = ram + 0x101 + (v))
80 #define GET_SP() (int(sp - 0x101 - ram))
81
82 #if SPC_NO_SP_WRAPAROUND
83 #define PUSH16( v ) (sp -= 2, SET_LE16( sp, v ))
84 #define PUSH( v ) (void) (*--sp = (uint8_t) (v))
85 #define POP( out ) (void) ((out) = *sp++)
86
87 #else
88 #define PUSH16( data )\
89 {\
90 int addr = int((sp -= 2) - ram);\
91 if ( addr > 0x100 )\
92 {\
93 SET_LE16( sp, data );\
94 }\
95 else\
96 {\
97 ram [(uint8_t) addr + 0x100] = (uint8_t) data;\
98 sp [1] = (uint8_t) (data >> 8);\
99 sp += 0x100;\
100 }\
101 }
102
103 #define PUSH( data )\
104 {\
105 *--sp = (uint8_t) (data);\
106 if ( sp - ram == 0x100 )\
107 sp += 0x100;\
108 }
109
110 #define POP( out )\
111 {\
112 out = *sp++;\
113 if ( sp - ram == 0x201 )\
114 {\
115 out = sp [-0x101];\
116 sp -= 0x100;\
117 }\
118 }
119
120 #endif
121
122 #define MEM_BIT( rel ) CPU_mem_bit( pc, rel_time + rel )
123
CPU_mem_bit(uint8_t const * pc,rel_time_t rel_time)124 unsigned SNES_SPC::CPU_mem_bit( uint8_t const* pc, rel_time_t rel_time )
125 {
126 unsigned addr = READ_PC16( pc );
127 unsigned t = READ( 0, addr & 0x1FFF ) >> (addr >> 13);
128 return t << 8 & 0x100;
129 }
130
131 //// Status flag handling
132
133 // Hex value in name to clarify code and bit shifting.
134 // Flag stored in indicated variable during emulation
135 int const n80 = 0x80; // nz
136 int const v40 = 0x40; // psw
137 int const p20 = 0x20; // dp
138 int const b10 = 0x10; // psw
139 int const h08 = 0x08; // psw
140 int const i04 = 0x04; // psw
141 int const z02 = 0x02; // nz
142 int const c01 = 0x01; // c
143
144 int const nz_neg_mask = 0x880; // either bit set indicates N flag set
145
146 #define GET_PSW( out )\
147 {\
148 out = psw & ~(n80 | p20 | z02 | c01);\
149 out |= c >> 8 & c01;\
150 out |= dp >> 3 & p20;\
151 out |= ((nz >> 4) | nz) & n80;\
152 if ( !(uint8_t) nz ) out |= z02;\
153 }
154
155 #define SET_PSW( in )\
156 {\
157 psw = in;\
158 c = in << 8;\
159 dp = in << 3 & 0x100;\
160 nz = (in << 4 & 0x800) | (~in & z02);\
161 }
162
163 SPC_CPU_RUN_FUNC
164 {
165 uint8_t* const ram = RAM;
166 int a = m.cpu_regs.a;
167 int x = m.cpu_regs.x;
168 int y = m.cpu_regs.y;
169 uint8_t const* pc;
170 uint8_t* sp;
171 int psw;
172 int c;
173 int nz;
174 int dp;
175
176 SET_PC( m.cpu_regs.pc );
177 SET_SP( m.cpu_regs.sp );
178 SET_PSW( m.cpu_regs.psw );
179
180 goto loop;
181
182
183 // Main loop
184
185 cbranch_taken_loop:
186 pc += *(BOOST::int8_t const*) pc;
187 inc_pc_loop:
188 pc++;
189 loop:
190 {
191 unsigned opcode;
192 unsigned data;
193
194 check( (unsigned) a < 0x100 );
195 check( (unsigned) x < 0x100 );
196 check( (unsigned) y < 0x100 );
197
198 opcode = *pc;
199 if ( (rel_time += m.cycle_table [opcode]) > 0 )
200 goto out_of_time;
201
202 #ifdef SPC_CPU_OPCODE_HOOK
203 SPC_CPU_OPCODE_HOOK( GET_PC(), opcode );
204 #endif
205 /*
206 //SUB_CASE_COUNTER( 1 );
207 #define PROFILE_TIMER_LOOP( op, addr, len )\
208 if ( opcode == op )\
209 {\
210 int cond = (unsigned) ((addr) - 0xFD) < 3 &&\
211 pc [len] == 0xF0 && pc [len+1] == 0xFE - len;\
212 SUB_CASE_COUNTER( op && cond );\
213 }
214
215 PROFILE_TIMER_LOOP( 0xEC, GET_LE16( pc + 1 ), 3 );
216 PROFILE_TIMER_LOOP( 0xEB, pc [1], 2 );
217 PROFILE_TIMER_LOOP( 0xE4, pc [1], 2 );
218 */
219
220 // TODO: if PC is at end of memory, this will get wrong operand (very obscure)
221 data = *++pc;
222 switch ( opcode )
223 {
224
225 // Common instructions
226
227 #define BRANCH( cond )\
228 {\
229 pc++;\
230 pc += (BOOST::int8_t) data;\
231 if ( cond )\
232 goto loop;\
233 pc -= (BOOST::int8_t) data;\
234 rel_time -= 2;\
235 goto loop;\
236 }
237
238 case 0xF0: // BEQ
239 BRANCH( !(uint8_t) nz ) // 89% taken
240
241 case 0xD0: // BNE
242 BRANCH( (uint8_t) nz )
243
244 case 0x3F:{// CALL
245 int old_addr = GET_PC() + 2;
246 SET_PC( READ_PC16( pc ) );
247 PUSH16( old_addr );
248 goto loop;
249 }
250
251 case 0x6F:// RET
252 #if SPC_NO_SP_WRAPAROUND
253 {
254 SET_PC( GET_LE16( sp ) );
255 sp += 2;
256 }
257 #else
258 {
259 int addr = int(sp - ram);
260 SET_PC( GET_LE16( sp ) );
261 sp += 2;
262 if ( addr < 0x1FF )
263 goto loop;
264
265 SET_PC( sp [-0x101] * 0x100 + ram [(uint8_t) addr + 0x100] );
266 sp -= 0x100;
267 }
268 #endif
269 goto loop;
270
271 case 0xE4: // MOV a,dp
272 ++pc;
273 // 80% from timer
274 READ_DP_TIMER( 0, data, a = nz );
275 goto loop;
276
277 case 0xFA:{// MOV dp,dp
278 int temp;
279 READ_DP_TIMER( -2, data, temp );
280 data = temp + no_read_before_write ;
281 }
282 // fall through
283 case 0x8F:{// MOV dp,#imm
284 int temp = READ_PC( pc + 1 );
285 pc += 2;
286
287 #if !SPC_MORE_ACCURACY
288 {
289 int i = dp + temp;
290 ram [i] = (uint8_t) data;
291 i -= 0xF0;
292 if ( (unsigned) i < 0x10 ) // 76%
293 {
294 REGS [i] = (uint8_t) data;
295
296 // Registers other than $F2 and $F4-$F7
297 //if ( i != 2 && i != 4 && i != 5 && i != 6 && i != 7 )
298 if ( (int) ((~0x2F00u << (bits_in_int - 16)) << i) < 0 ) // 12%
299 cpu_write_smp_reg( data, rel_time, i );
300 }
301 }
302 #else
303 WRITE_DP( 0, temp, data );
304 #endif
305 goto loop;
306 }
307
308 case 0xC4: // MOV dp,a
309 ++pc;
310 #if !SPC_MORE_ACCURACY
311 {
312 int i = dp + data;
313 ram [i] = (uint8_t) a;
314 i -= 0xF0;
315 if ( (unsigned) i < 0x10 ) // 39%
316 {
317 unsigned sel = i - 2;
318 REGS [i] = (uint8_t) a;
319
320 if ( sel == 1 ) // 51% $F3
321 dsp_write( a, rel_time );
322 else if ( sel > 1 ) // 1% not $F2 or $F3
323 cpu_write_smp_reg_( a, rel_time, i );
324 }
325 }
326 #else
327 WRITE_DP( 0, data, a );
328 #endif
329 goto loop;
330
331 #define CASE( n ) case n:
332
333 // Define common address modes based on opcode for immediate mode. Execution
334 // ends with data set to the address of the operand.
335 #define ADDR_MODES_( op )\
336 CASE( op - 0x02 ) /* (X) */\
337 data = x + dp;\
338 pc--;\
339 goto end_##op;\
340 CASE( op + 0x0F ) /* (dp)+Y */\
341 data = READ_PROG16( data + dp ) + y;\
342 goto end_##op;\
343 CASE( op - 0x01 ) /* (dp+X) */\
344 data = READ_PROG16( ((uint8_t) (data + x)) + dp );\
345 goto end_##op;\
346 CASE( op + 0x0E ) /* abs+Y */\
347 data += y;\
348 goto abs_##op;\
349 CASE( op + 0x0D ) /* abs+X */\
350 data += x;\
351 CASE( op - 0x03 ) /* abs */\
352 abs_##op:\
353 data += 0x100 * READ_PC( ++pc );\
354 goto end_##op;\
355 CASE( op + 0x0C ) /* dp+X */\
356 data = (uint8_t) (data + x);
357
358 #define ADDR_MODES_NO_DP( op )\
359 ADDR_MODES_( op )\
360 data += dp;\
361 end_##op:
362
363 #define ADDR_MODES( op )\
364 ADDR_MODES_( op )\
365 CASE( op - 0x04 ) /* dp */\
366 data += dp;\
367 end_##op:
368
369 // 1. 8-bit Data Transmission Commands. Group I
370
371 ADDR_MODES_NO_DP( 0xE8 ) // MOV A,addr
372 a = nz = READ( 0, data );
373 goto inc_pc_loop;
374
375 case 0xBF:{// MOV A,(X)+
376 int temp = x + dp;
377 x = (uint8_t) (x + 1);
378 a = nz = READ( -1, temp );
379 goto loop;
380 }
381
382 case 0xE8: // MOV A,imm
383 a = data;
384 nz = data;
385 goto inc_pc_loop;
386
387 case 0xF9: // MOV X,dp+Y
388 data = (uint8_t) (data + y);
389 case 0xF8: // MOV X,dp
390 READ_DP_TIMER( 0, data, x = nz );
391 goto inc_pc_loop;
392
393 case 0xE9: // MOV X,abs
394 data = READ_PC16( pc );
395 ++pc;
396 data = READ( 0, data );
397 case 0xCD: // MOV X,imm
398 x = data;
399 nz = data;
400 goto inc_pc_loop;
401
402 case 0xFB: // MOV Y,dp+X
403 data = (uint8_t) (data + x);
404 case 0xEB: // MOV Y,dp
405 // 70% from timer
406 pc++;
407 READ_DP_TIMER( 0, data, y = nz );
408 goto loop;
409
410 case 0xEC:{// MOV Y,abs
411 int temp = READ_PC16( pc );
412 pc += 2;
413 READ_TIMER( 0, temp, y = nz );
414 //y = nz = READ( 0, temp );
415 goto loop;
416 }
417
418 case 0x8D: // MOV Y,imm
419 y = data;
420 nz = data;
421 goto inc_pc_loop;
422
423 // 2. 8-BIT DATA TRANSMISSION COMMANDS, GROUP 2
424
425 ADDR_MODES_NO_DP( 0xC8 ) // MOV addr,A
426 WRITE( 0, data, a );
427 goto inc_pc_loop;
428
429 {
430 int temp;
431 case 0xCC: // MOV abs,Y
432 temp = y;
433 goto mov_abs_temp;
434 case 0xC9: // MOV abs,X
435 temp = x;
436 mov_abs_temp:
437 WRITE( 0, READ_PC16( pc ), temp );
438 pc += 2;
439 goto loop;
440 }
441
442 case 0xD9: // MOV dp+Y,X
443 data = (uint8_t) (data + y);
444 case 0xD8: // MOV dp,X
445 WRITE( 0, data + dp, x );
446 goto inc_pc_loop;
447
448 case 0xDB: // MOV dp+X,Y
449 data = (uint8_t) (data + x);
450 case 0xCB: // MOV dp,Y
451 WRITE( 0, data + dp, y );
452 goto inc_pc_loop;
453
454 // 3. 8-BIT DATA TRANSMISSIN COMMANDS, GROUP 3.
455
456 case 0x7D: // MOV A,X
457 a = x;
458 nz = x;
459 goto loop;
460
461 case 0xDD: // MOV A,Y
462 a = y;
463 nz = y;
464 goto loop;
465
466 case 0x5D: // MOV X,A
467 x = a;
468 nz = a;
469 goto loop;
470
471 case 0xFD: // MOV Y,A
472 y = a;
473 nz = a;
474 goto loop;
475
476 case 0x9D: // MOV X,SP
477 x = nz = GET_SP();
478 goto loop;
479
480 case 0xBD: // MOV SP,X
481 SET_SP( x );
482 goto loop;
483
484 //case 0xC6: // MOV (X),A (handled by MOV addr,A in group 2)
485
486 case 0xAF: // MOV (X)+,A
487 WRITE_DP( 0, x, a + no_read_before_write );
488 x++;
489 goto loop;
490
491 // 5. 8-BIT LOGIC OPERATION COMMANDS
492
493 #define LOGICAL_OP( op, func )\
494 ADDR_MODES( op ) /* addr */\
495 data = READ( 0, data );\
496 case op: /* imm */\
497 nz = a func##= data;\
498 goto inc_pc_loop;\
499 { unsigned addr;\
500 case op + 0x11: /* X,Y */\
501 data = READ_DP( -2, y );\
502 addr = x + dp;\
503 goto addr_##op;\
504 case op + 0x01: /* dp,dp */\
505 data = READ_DP( -3, data );\
506 case op + 0x10:{/*dp,imm*/\
507 uint8_t const* addr2 = pc + 1;\
508 pc += 2;\
509 addr = READ_PC( addr2 ) + dp;\
510 }\
511 addr_##op:\
512 nz = data func READ( -1, addr );\
513 WRITE( 0, addr, nz );\
514 goto loop;\
515 }
516
517 LOGICAL_OP( 0x28, & ); // AND
518
519 LOGICAL_OP( 0x08, | ); // OR
520
521 LOGICAL_OP( 0x48, ^ ); // EOR
522
523 // 4. 8-BIT ARITHMETIC OPERATION COMMANDS
524
525 ADDR_MODES( 0x68 ) // CMP addr
526 data = READ( 0, data );
527 case 0x68: // CMP imm
528 nz = a - data;
529 c = ~nz;
530 nz &= 0xFF;
531 goto inc_pc_loop;
532
533 case 0x79: // CMP (X),(Y)
534 data = READ_DP( -2, y );
535 nz = READ_DP( -1, x ) - data;
536 c = ~nz;
537 nz &= 0xFF;
538 goto loop;
539
540 case 0x69: // CMP dp,dp
541 data = READ_DP( -3, data );
542 case 0x78: // CMP dp,imm
543 nz = READ_DP( -1, READ_PC( ++pc ) ) - data;
544 c = ~nz;
545 nz &= 0xFF;
546 goto inc_pc_loop;
547
548 case 0x3E: // CMP X,dp
549 data += dp;
550 goto cmp_x_addr;
551 case 0x1E: // CMP X,abs
552 data = READ_PC16( pc );
553 pc++;
554 cmp_x_addr:
555 data = READ( 0, data );
556 case 0xC8: // CMP X,imm
557 nz = x - data;
558 c = ~nz;
559 nz &= 0xFF;
560 goto inc_pc_loop;
561
562 case 0x7E: // CMP Y,dp
563 data += dp;
564 goto cmp_y_addr;
565 case 0x5E: // CMP Y,abs
566 data = READ_PC16( pc );
567 pc++;
568 cmp_y_addr:
569 data = READ( 0, data );
570 case 0xAD: // CMP Y,imm
571 nz = y - data;
572 c = ~nz;
573 nz &= 0xFF;
574 goto inc_pc_loop;
575
576 {
577 int addr;
578 case 0xB9: // SBC (x),(y)
579 case 0x99: // ADC (x),(y)
580 pc--; // compensate for inc later
581 data = READ_DP( -2, y );
582 addr = x + dp;
583 goto adc_addr;
584 case 0xA9: // SBC dp,dp
585 case 0x89: // ADC dp,dp
586 data = READ_DP( -3, data );
587 case 0xB8: // SBC dp,imm
588 case 0x98: // ADC dp,imm
589 addr = READ_PC( ++pc ) + dp;
590 adc_addr:
591 nz = READ( -1, addr );
592 goto adc_data;
593
594 // catch ADC and SBC together, then decode later based on operand
595 #undef CASE
596 #define CASE( n ) case n: case (n) + 0x20:
597 ADDR_MODES( 0x88 ) // ADC/SBC addr
598 data = READ( 0, data );
599 case 0xA8: // SBC imm
600 case 0x88: // ADC imm
601 addr = -1; // A
602 nz = a;
603 adc_data: {
604 int flags;
605 if ( opcode >= 0xA0 ) // SBC
606 data ^= 0xFF;
607
608 flags = data ^ nz;
609 nz += data + (c >> 8 & 1);
610 flags ^= nz;
611
612 psw = (psw & ~(v40 | h08)) |
613 (flags >> 1 & h08) |
614 ((flags + 0x80) >> 2 & v40);
615 c = nz;
616 if ( addr < 0 )
617 {
618 a = (uint8_t) nz;
619 goto inc_pc_loop;
620 }
621 WRITE( 0, addr, /*(uint8_t)*/ nz );
622 goto inc_pc_loop;
623 }
624
625 }
626
627 // 6. ADDITION & SUBTRACTION COMMANDS
628
629 #define INC_DEC_REG( reg, op )\
630 nz = reg op;\
631 reg = (uint8_t) nz;\
632 goto loop;
633
634 case 0xBC: INC_DEC_REG( a, + 1 ) // INC A
635 case 0x3D: INC_DEC_REG( x, + 1 ) // INC X
636 case 0xFC: INC_DEC_REG( y, + 1 ) // INC Y
637
638 case 0x9C: INC_DEC_REG( a, - 1 ) // DEC A
639 case 0x1D: INC_DEC_REG( x, - 1 ) // DEC X
640 case 0xDC: INC_DEC_REG( y, - 1 ) // DEC Y
641
642 case 0x9B: // DEC dp+X
643 case 0xBB: // INC dp+X
644 data = (uint8_t) (data + x);
645 case 0x8B: // DEC dp
646 case 0xAB: // INC dp
647 data += dp;
648 goto inc_abs;
649 case 0x8C: // DEC abs
650 case 0xAC: // INC abs
651 data = READ_PC16( pc );
652 pc++;
653 inc_abs:
654 nz = (opcode >> 4 & 2) - 1;
655 nz += READ( -1, data );
656 WRITE( 0, data, /*(uint8_t)*/ nz );
657 goto inc_pc_loop;
658
659 // 7. SHIFT, ROTATION COMMANDS
660
661 case 0x5C: // LSR A
662 c = 0;
663 case 0x7C:{// ROR A
664 nz = (c >> 1 & 0x80) | (a >> 1);
665 c = a << 8;
666 a = nz;
667 goto loop;
668 }
669
670 case 0x1C: // ASL A
671 c = 0;
672 case 0x3C:{// ROL A
673 int temp = c >> 8 & 1;
674 c = a << 1;
675 nz = c | temp;
676 a = (uint8_t) nz;
677 goto loop;
678 }
679
680 case 0x0B: // ASL dp
681 c = 0;
682 data += dp;
683 goto rol_mem;
684 case 0x1B: // ASL dp+X
685 c = 0;
686 case 0x3B: // ROL dp+X
687 data = (uint8_t) (data + x);
688 case 0x2B: // ROL dp
689 data += dp;
690 goto rol_mem;
691 case 0x0C: // ASL abs
692 c = 0;
693 case 0x2C: // ROL abs
694 data = READ_PC16( pc );
695 pc++;
696 rol_mem:
697 nz = c >> 8 & 1;
698 nz |= (c = READ( -1, data ) << 1);
699 WRITE( 0, data, /*(uint8_t)*/ nz );
700 goto inc_pc_loop;
701
702 case 0x4B: // LSR dp
703 c = 0;
704 data += dp;
705 goto ror_mem;
706 case 0x5B: // LSR dp+X
707 c = 0;
708 case 0x7B: // ROR dp+X
709 data = (uint8_t) (data + x);
710 case 0x6B: // ROR dp
711 data += dp;
712 goto ror_mem;
713 case 0x4C: // LSR abs
714 c = 0;
715 case 0x6C: // ROR abs
716 data = READ_PC16( pc );
717 pc++;
718 ror_mem: {
719 int temp = READ( -1, data );
720 nz = (c >> 1 & 0x80) | (temp >> 1);
721 c = temp << 8;
722 WRITE( 0, data, nz );
723 goto inc_pc_loop;
724 }
725
726 case 0x9F: // XCN
727 nz = a = (a >> 4) | (uint8_t) (a << 4);
728 goto loop;
729
730 // 8. 16-BIT TRANSMISION COMMANDS
731
732 case 0xBA: // MOVW YA,dp
733 a = READ_DP( -2, data );
734 nz = (a & 0x7F) | (a >> 1);
735 y = READ_DP( 0, (uint8_t) (data + 1) );
736 nz |= y;
737 goto inc_pc_loop;
738
739 case 0xDA: // MOVW dp,YA
740 WRITE_DP( -1, data, a );
741 WRITE_DP( 0, (uint8_t) (data + 1), y + no_read_before_write );
742 goto inc_pc_loop;
743
744 // 9. 16-BIT OPERATION COMMANDS
745
746 case 0x3A: // INCW dp
747 case 0x1A:{// DECW dp
748 int temp;
749 // low byte
750 data += dp;
751 temp = READ( -3, data );
752 temp += (opcode >> 4 & 2) - 1; // +1 for INCW, -1 for DECW
753 nz = ((temp >> 1) | temp) & 0x7F;
754 WRITE( -2, data, /*(uint8_t)*/ temp );
755
756 // high byte
757 data = (uint8_t) (data + 1) + dp;
758 temp = (uint8_t) ((temp >> 8) + READ( -1, data ));
759 nz |= temp;
760 WRITE( 0, data, temp );
761
762 goto inc_pc_loop;
763 }
764
765 case 0x7A: // ADDW YA,dp
766 case 0x9A:{// SUBW YA,dp
767 int lo = READ_DP( -2, data );
768 int hi = READ_DP( 0, (uint8_t) (data + 1) );
769 int result;
770 int flags;
771
772 if ( opcode == 0x9A ) // SUBW
773 {
774 lo = (lo ^ 0xFF) + 1;
775 hi ^= 0xFF;
776 }
777
778 lo += a;
779 result = y + hi + (lo >> 8);
780 flags = hi ^ y ^ result;
781
782 psw = (psw & ~(v40 | h08)) |
783 (flags >> 1 & h08) |
784 ((flags + 0x80) >> 2 & v40);
785 c = result;
786 a = (uint8_t) lo;
787 result = (uint8_t) result;
788 y = result;
789 nz = (((lo >> 1) | lo) & 0x7F) | result;
790
791 goto inc_pc_loop;
792 }
793
794 case 0x5A: { // CMPW YA,dp
795 int temp = a - READ_DP( -1, data );
796 nz = ((temp >> 1) | temp) & 0x7F;
797 temp = y + (temp >> 8);
798 temp -= READ_DP( 0, (uint8_t) (data + 1) );
799 nz |= temp;
800 c = ~temp;
801 nz &= 0xFF;
802 goto inc_pc_loop;
803 }
804
805 // 10. MULTIPLICATION & DIVISON COMMANDS
806
807 case 0xCF: { // MUL YA
808 unsigned temp = y * a;
809 a = (uint8_t) temp;
810 nz = ((temp >> 1) | temp) & 0x7F;
811 y = temp >> 8;
812 nz |= y;
813 goto loop;
814 }
815
816 case 0x9E: // DIV YA,X
817 {
818 unsigned ya = y * 0x100 + a;
819
820 psw &= ~(h08 | v40);
821
822 if ( y >= x )
823 psw |= v40;
824
825 if ( (y & 15) >= (x & 15) )
826 psw |= h08;
827
828 if ( y < x * 2 )
829 {
830 a = ya / x;
831 y = ya - a * x;
832 }
833 else
834 {
835 a = 255 - (ya - x * 0x200) / (256 - x);
836 y = x + (ya - x * 0x200) % (256 - x);
837 }
838
839 nz = (uint8_t) a;
840 a = (uint8_t) a;
841
842 goto loop;
843 }
844
845 // 11. DECIMAL COMPENSATION COMMANDS
846
847 case 0xDF: // DAA
848 SUSPICIOUS_OPCODE( "DAA" );
849 if ( a > 0x99 || c & 0x100 )
850 {
851 a += 0x60;
852 c = 0x100;
853 }
854
855 if ( (a & 0x0F) > 9 || psw & h08 )
856 a += 0x06;
857
858 nz = a;
859 a = (uint8_t) a;
860 goto loop;
861
862 case 0xBE: // DAS
863 SUSPICIOUS_OPCODE( "DAS" );
864 if ( a > 0x99 || !(c & 0x100) )
865 {
866 a -= 0x60;
867 c = 0;
868 }
869
870 if ( (a & 0x0F) > 9 || !(psw & h08) )
871 a -= 0x06;
872
873 nz = a;
874 a = (uint8_t) a;
875 goto loop;
876
877 // 12. BRANCHING COMMANDS
878
879 case 0x2F: // BRA rel
880 pc += (BOOST::int8_t) data;
881 goto inc_pc_loop;
882
883 case 0x30: // BMI
884 BRANCH( (nz & nz_neg_mask) )
885
886 case 0x10: // BPL
887 BRANCH( !(nz & nz_neg_mask) )
888
889 case 0xB0: // BCS
890 BRANCH( c & 0x100 )
891
892 case 0x90: // BCC
893 BRANCH( !(c & 0x100) )
894
895 case 0x70: // BVS
896 BRANCH( psw & v40 )
897
898 case 0x50: // BVC
899 BRANCH( !(psw & v40) )
900
901 #define CBRANCH( cond )\
902 {\
903 pc++;\
904 if ( cond )\
905 goto cbranch_taken_loop;\
906 rel_time -= 2;\
907 goto inc_pc_loop;\
908 }
909
910 case 0x03: // BBS dp.bit,rel
911 case 0x23:
912 case 0x43:
913 case 0x63:
914 case 0x83:
915 case 0xA3:
916 case 0xC3:
917 case 0xE3:
918 CBRANCH( READ_DP( -4, data ) >> (opcode >> 5) & 1 )
919
920 case 0x13: // BBC dp.bit,rel
921 case 0x33:
922 case 0x53:
923 case 0x73:
924 case 0x93:
925 case 0xB3:
926 case 0xD3:
927 case 0xF3:
928 CBRANCH( !(READ_DP( -4, data ) >> (opcode >> 5) & 1) )
929
930 case 0xDE: // CBNE dp+X,rel
931 data = (uint8_t) (data + x);
932 // fall through
933 case 0x2E:{// CBNE dp,rel
934 int temp;
935 // 61% from timer
936 READ_DP_TIMER( -4, data, temp );
937 CBRANCH( temp != a )
938 }
939
940 case 0x6E: { // DBNZ dp,rel
941 unsigned temp = READ_DP( -4, data ) - 1;
942 WRITE_DP( -3, (uint8_t) data, /*(uint8_t)*/ temp + no_read_before_write );
943 CBRANCH( temp )
944 }
945
946 case 0xFE: // DBNZ Y,rel
947 y = (uint8_t) (y - 1);
948 BRANCH( y )
949
950 case 0x1F: // JMP [abs+X]
951 SET_PC( READ_PC16( pc ) + x );
952 // fall through
953 case 0x5F: // JMP abs
954 SET_PC( READ_PC16( pc ) );
955 goto loop;
956
957 // 13. SUB-ROUTINE CALL RETURN COMMANDS
958
959 case 0x0F:{// BRK
960 int temp;
961 int ret_addr = GET_PC();
962 SUSPICIOUS_OPCODE( "BRK" );
963 SET_PC( READ_PROG16( 0xFFDE ) ); // vector address verified
964 PUSH16( ret_addr );
965 GET_PSW( temp );
966 psw = (psw | b10) & ~i04;
967 PUSH( temp );
968 goto loop;
969 }
970
971 case 0x4F:{// PCALL offset
972 int ret_addr = GET_PC() + 1;
973 SET_PC( 0xFF00 | data );
974 PUSH16( ret_addr );
975 goto loop;
976 }
977
978 case 0x01: // TCALL n
979 case 0x11:
980 case 0x21:
981 case 0x31:
982 case 0x41:
983 case 0x51:
984 case 0x61:
985 case 0x71:
986 case 0x81:
987 case 0x91:
988 case 0xA1:
989 case 0xB1:
990 case 0xC1:
991 case 0xD1:
992 case 0xE1:
993 case 0xF1: {
994 int ret_addr = GET_PC();
995 SET_PC( READ_PROG16( 0xFFDE - (opcode >> 3) ) );
996 PUSH16( ret_addr );
997 goto loop;
998 }
999
1000 // 14. STACK OPERATION COMMANDS
1001
1002 {
1003 int temp;
1004 case 0x7F: // RET1
1005 temp = *sp;
1006 SET_PC( GET_LE16( sp + 1 ) );
1007 sp += 3;
1008 goto set_psw;
1009 case 0x8E: // POP PSW
1010 POP( temp );
1011 set_psw:
1012 SET_PSW( temp );
1013 goto loop;
1014 }
1015
1016 case 0x0D: { // PUSH PSW
1017 int temp;
1018 GET_PSW( temp );
1019 PUSH( temp );
1020 goto loop;
1021 }
1022
1023 case 0x2D: // PUSH A
1024 PUSH( a );
1025 goto loop;
1026
1027 case 0x4D: // PUSH X
1028 PUSH( x );
1029 goto loop;
1030
1031 case 0x6D: // PUSH Y
1032 PUSH( y );
1033 goto loop;
1034
1035 case 0xAE: // POP A
1036 POP( a );
1037 goto loop;
1038
1039 case 0xCE: // POP X
1040 POP( x );
1041 goto loop;
1042
1043 case 0xEE: // POP Y
1044 POP( y );
1045 goto loop;
1046
1047 // 15. BIT OPERATION COMMANDS
1048
1049 case 0x02: // SET1
1050 case 0x22:
1051 case 0x42:
1052 case 0x62:
1053 case 0x82:
1054 case 0xA2:
1055 case 0xC2:
1056 case 0xE2:
1057 case 0x12: // CLR1
1058 case 0x32:
1059 case 0x52:
1060 case 0x72:
1061 case 0x92:
1062 case 0xB2:
1063 case 0xD2:
1064 case 0xF2: {
1065 int bit = 1 << (opcode >> 5);
1066 int mask = ~bit;
1067 if ( opcode & 0x10 )
1068 bit = 0;
1069 data += dp;
1070 WRITE( 0, data, (READ( -1, data ) & mask) | bit );
1071 goto inc_pc_loop;
1072 }
1073
1074 case 0x0E: // TSET1 abs
1075 case 0x4E: // TCLR1 abs
1076 data = READ_PC16( pc );
1077 pc += 2;
1078 {
1079 unsigned temp = READ( -2, data );
1080 nz = (uint8_t) (a - temp);
1081 temp &= ~a;
1082 if ( opcode == 0x0E )
1083 temp |= a;
1084 WRITE( 0, data, temp );
1085 }
1086 goto loop;
1087
1088 case 0x4A: // AND1 C,mem.bit
1089 c &= MEM_BIT( 0 );
1090 pc += 2;
1091 goto loop;
1092
1093 case 0x6A: // AND1 C,/mem.bit
1094 c &= ~MEM_BIT( 0 );
1095 pc += 2;
1096 goto loop;
1097
1098 case 0x0A: // OR1 C,mem.bit
1099 c |= MEM_BIT( -1 );
1100 pc += 2;
1101 goto loop;
1102
1103 case 0x2A: // OR1 C,/mem.bit
1104 c |= ~MEM_BIT( -1 );
1105 pc += 2;
1106 goto loop;
1107
1108 case 0x8A: // EOR1 C,mem.bit
1109 c ^= MEM_BIT( -1 );
1110 pc += 2;
1111 goto loop;
1112
1113 case 0xEA: // NOT1 mem.bit
1114 data = READ_PC16( pc );
1115 pc += 2;
1116 {
1117 unsigned temp = READ( -1, data & 0x1FFF );
1118 temp ^= 1 << (data >> 13);
1119 WRITE( 0, data & 0x1FFF, temp );
1120 }
1121 goto loop;
1122
1123 case 0xCA: // MOV1 mem.bit,C
1124 data = READ_PC16( pc );
1125 pc += 2;
1126 {
1127 unsigned temp = READ( -2, data & 0x1FFF );
1128 unsigned bit = data >> 13;
1129 temp = (temp & ~(1 << bit)) | ((c >> 8 & 1) << bit);
1130 WRITE( 0, data & 0x1FFF, temp + no_read_before_write );
1131 }
1132 goto loop;
1133
1134 case 0xAA: // MOV1 C,mem.bit
1135 c = MEM_BIT( 0 );
1136 pc += 2;
1137 goto loop;
1138
1139 // 16. PROGRAM PSW FLAG OPERATION COMMANDS
1140
1141 case 0x60: // CLRC
1142 c = 0;
1143 goto loop;
1144
1145 case 0x80: // SETC
1146 c = ~0;
1147 goto loop;
1148
1149 case 0xED: // NOTC
1150 c ^= 0x100;
1151 goto loop;
1152
1153 case 0xE0: // CLRV
1154 psw &= ~(v40 | h08);
1155 goto loop;
1156
1157 case 0x20: // CLRP
1158 dp = 0;
1159 goto loop;
1160
1161 case 0x40: // SETP
1162 dp = 0x100;
1163 goto loop;
1164
1165 case 0xA0: // EI
1166 SUSPICIOUS_OPCODE( "EI" );
1167 psw |= i04;
1168 goto loop;
1169
1170 case 0xC0: // DI
1171 SUSPICIOUS_OPCODE( "DI" );
1172 psw &= ~i04;
1173 goto loop;
1174
1175 // 17. OTHER COMMANDS
1176
1177 case 0x00: // NOP
1178 goto loop;
1179
1180 case 0xFF:{// STOP
1181 // handle PC wrap-around
1182 unsigned addr = GET_PC() - 1;
1183 if ( addr >= 0x10000 )
1184 {
1185 addr &= 0xFFFF;
1186 SET_PC( addr );
1187 dprintf( "SPC: PC wrapped around\n" );
1188 goto loop;
1189 }
1190 }
1191 // fall through
1192 case 0xEF: // SLEEP
1193 SUSPICIOUS_OPCODE( "STOP/SLEEP" );
1194 --pc;
1195 rel_time = 0;
1196 m.cpu_error = "SPC emulation error";
1197 goto stop;
1198 } // switch
1199
1200 assert( 0 ); // catch any unhandled instructions
1201 }
1202 out_of_time:
1203 rel_time -= m.cycle_table [*pc]; // undo partial execution of opcode
1204 stop:
1205
1206 // Uncache registers
1207 if ( GET_PC() >= 0x10000 )
1208 dprintf( "SPC: PC wrapped around\n" );
1209 m.cpu_regs.pc = (uint16_t) GET_PC();
1210 m.cpu_regs.sp = ( uint8_t) GET_SP();
1211 m.cpu_regs.a = ( uint8_t) a;
1212 m.cpu_regs.x = ( uint8_t) x;
1213 m.cpu_regs.y = ( uint8_t) y;
1214 {
1215 int temp;
1216 GET_PSW( temp );
1217 m.cpu_regs.psw = (uint8_t) temp;
1218 }
1219 }
1220 SPC_CPU_RUN_FUNC_END
1221