all repos — mgba @ bf7247ad4c6e30b428d444607f14242f8f4f4a2d

mGBA Game Boy Advance Emulator

src/gb/io.c (view raw)

  1/* Copyright (c) 2013-2016 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include <mgba/internal/gb/io.h>
  7
  8#include <mgba/internal/gb/gb.h>
  9#include <mgba/internal/gb/sio.h>
 10#include <mgba/internal/gb/serialize.h>
 11
 12mLOG_DEFINE_CATEGORY(GB_IO, "GB I/O", "gb.io");
 13
 14const char* const GBIORegisterNames[] = {
 15	[REG_JOYP] = "JOYP",
 16	[REG_SB] = "SB",
 17	[REG_SC] = "SC",
 18	[REG_DIV] = "DIV",
 19	[REG_TIMA] = "TIMA",
 20	[REG_TMA] = "TMA",
 21	[REG_TAC] = "TAC",
 22	[REG_IF] = "IF",
 23	[REG_NR10] = "NR10",
 24	[REG_NR11] = "NR11",
 25	[REG_NR12] = "NR12",
 26	[REG_NR13] = "NR13",
 27	[REG_NR14] = "NR14",
 28	[REG_NR21] = "NR21",
 29	[REG_NR22] = "NR22",
 30	[REG_NR23] = "NR23",
 31	[REG_NR24] = "NR24",
 32	[REG_NR30] = "NR30",
 33	[REG_NR31] = "NR31",
 34	[REG_NR32] = "NR32",
 35	[REG_NR33] = "NR33",
 36	[REG_NR34] = "NR34",
 37	[REG_NR41] = "NR41",
 38	[REG_NR42] = "NR42",
 39	[REG_NR43] = "NR43",
 40	[REG_NR44] = "NR44",
 41	[REG_NR50] = "NR50",
 42	[REG_NR51] = "NR51",
 43	[REG_NR52] = "NR52",
 44	[REG_LCDC] = "LCDC",
 45	[REG_STAT] = "STAT",
 46	[REG_SCY] = "SCY",
 47	[REG_SCX] = "SCX",
 48	[REG_LY] = "LY",
 49	[REG_LYC] = "LYC",
 50	[REG_DMA] = "DMA",
 51	[REG_BGP] = "BGP",
 52	[REG_OBP0] = "OBP0",
 53	[REG_OBP1] = "OBP1",
 54	[REG_WY] = "WY",
 55	[REG_WX] = "WX",
 56	[REG_KEY1] = "KEY1",
 57	[REG_VBK] = "VBK",
 58	[REG_HDMA1] = "HDMA1",
 59	[REG_HDMA2] = "HDMA2",
 60	[REG_HDMA3] = "HDMA3",
 61	[REG_HDMA4] = "HDMA4",
 62	[REG_HDMA5] = "HDMA5",
 63	[REG_RP] = "RP",
 64	[REG_BCPS] = "BCPS",
 65	[REG_BCPD] = "BCPD",
 66	[REG_OCPS] = "OCPS",
 67	[REG_OCPD] = "OCPD",
 68	[REG_SVBK] = "SVBK",
 69	[REG_IE] = "IE",
 70};
 71
 72static const uint8_t _registerMask[] = {
 73	[REG_SC]   = 0x7E, // TODO: GBC differences
 74	[REG_IF]   = 0xE0,
 75	[REG_TAC]  = 0xF8,
 76	[REG_NR10] = 0x80,
 77	[REG_NR11] = 0x3F,
 78	[REG_NR12] = 0x00,
 79	[REG_NR13] = 0xFF,
 80	[REG_NR14] = 0xBF,
 81	[REG_NR21] = 0x3F,
 82	[REG_NR22] = 0x00,
 83	[REG_NR23] = 0xFF,
 84	[REG_NR24] = 0xBF,
 85	[REG_NR30] = 0x7F,
 86	[REG_NR31] = 0xFF,
 87	[REG_NR32] = 0x9F,
 88	[REG_NR33] = 0xFF,
 89	[REG_NR34] = 0xBF,
 90	[REG_NR41] = 0xFF,
 91	[REG_NR42] = 0x00,
 92	[REG_NR43] = 0x00,
 93	[REG_NR44] = 0xBF,
 94	[REG_NR50] = 0x00,
 95	[REG_NR51] = 0x00,
 96	[REG_NR52] = 0x70,
 97	[REG_STAT] = 0x80,
 98	[REG_KEY1] = 0x7E,
 99	[REG_VBK] = 0xFE,
100	[REG_OCPS] = 0x40,
101	[REG_BCPS] = 0x40,
102	[REG_UNK6C] = 0xFE,
103	[REG_SVBK] = 0xF8,
104	[REG_IE]   = 0xE0,
105};
106
107static void _writeSGBBits(struct GB* gb, int bits) {
108	if (!bits) {
109		gb->sgbBit = 0;
110		memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
111	}
112	if (bits == gb->currentSgbBits) {
113		return;
114	}
115	gb->currentSgbBits = bits;
116	if (gb->sgbBit == 128 && bits == 2) {
117		GBVideoWriteSGBPacket(&gb->video, gb->sgbPacket);
118		++gb->sgbBit;
119	}
120	if (gb->sgbBit >= 128) {
121		return;
122	}
123	switch (bits) {
124	case 1:
125		gb->sgbPacket[gb->sgbBit >> 3] |= 1 << (gb->sgbBit & 7);
126		// Fall through
127	case 2:
128		++gb->sgbBit;
129	default:
130		break;
131	}
132}
133
134void GBIOInit(struct GB* gb) {
135	memset(gb->memory.io, 0, sizeof(gb->memory.io));
136}
137
138void GBIOReset(struct GB* gb) {
139	memset(gb->memory.io, 0, sizeof(gb->memory.io));
140
141	GBIOWrite(gb, REG_TIMA, 0);
142	GBIOWrite(gb, REG_TMA, 0);
143	GBIOWrite(gb, REG_TAC, 0);
144	GBIOWrite(gb, REG_IF, 1);
145	GBIOWrite(gb, REG_NR52, 0xF1);
146	GBIOWrite(gb, REG_NR14, 0x3F);
147	GBIOWrite(gb, REG_NR10, 0x80);
148	GBIOWrite(gb, REG_NR11, 0xBF);
149	GBIOWrite(gb, REG_NR12, 0xF3);
150	GBIOWrite(gb, REG_NR13, 0xF3);
151	GBIOWrite(gb, REG_NR24, 0x3F);
152	GBIOWrite(gb, REG_NR21, 0x3F);
153	GBIOWrite(gb, REG_NR22, 0x00);
154	GBIOWrite(gb, REG_NR34, 0x3F);
155	GBIOWrite(gb, REG_NR30, 0x7F);
156	GBIOWrite(gb, REG_NR31, 0xFF);
157	GBIOWrite(gb, REG_NR32, 0x9F);
158	GBIOWrite(gb, REG_NR44, 0x3F);
159	GBIOWrite(gb, REG_NR41, 0xFF);
160	GBIOWrite(gb, REG_NR42, 0x00);
161	GBIOWrite(gb, REG_NR43, 0x00);
162	GBIOWrite(gb, REG_NR50, 0x77);
163	GBIOWrite(gb, REG_NR51, 0xF3);
164	GBIOWrite(gb, REG_LCDC, 0x91);
165	GBIOWrite(gb, REG_SCY, 0x00);
166	GBIOWrite(gb, REG_SCX, 0x00);
167	GBIOWrite(gb, REG_LYC, 0x00);
168	GBIOWrite(gb, REG_BGP, 0xFC);
169	if (gb->model < GB_MODEL_CGB) {
170		GBIOWrite(gb, REG_OBP0, 0xFF);
171		GBIOWrite(gb, REG_OBP1, 0xFF);
172	}
173	GBIOWrite(gb, REG_WY, 0x00);
174	GBIOWrite(gb, REG_WX, 0x00);
175	if (gb->model >= GB_MODEL_CGB) {
176		GBIOWrite(gb, REG_UNK4C, 0);
177		GBIOWrite(gb, REG_JOYP, 0xFF);
178		GBIOWrite(gb, REG_VBK, 0);
179		GBIOWrite(gb, REG_BCPS, 0);
180		GBIOWrite(gb, REG_OCPS, 0);
181		GBIOWrite(gb, REG_SVBK, 1);
182		GBIOWrite(gb, REG_HDMA1, 0xFF);
183		GBIOWrite(gb, REG_HDMA2, 0xFF);
184		GBIOWrite(gb, REG_HDMA3, 0xFF);
185		GBIOWrite(gb, REG_HDMA4, 0xFF);
186		gb->memory.io[REG_HDMA5] = 0xFF;
187	} else if (gb->model == GB_MODEL_SGB) {
188		GBIOWrite(gb, REG_JOYP, 0xFF);
189	}
190	GBIOWrite(gb, REG_IE, 0x00);
191}
192
193void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
194	switch (address) {
195	case REG_SB:
196		GBSIOWriteSB(&gb->sio, value);
197		break;
198	case REG_SC:
199		GBSIOWriteSC(&gb->sio, value);
200		break;
201	case REG_DIV:
202		GBTimerDivReset(&gb->timer);
203		return;
204	case REG_NR10:
205		if (gb->audio.enable) {
206			GBAudioWriteNR10(&gb->audio, value);
207		} else {
208			value = 0;
209		}
210		break;
211	case REG_NR11:
212		if (gb->audio.enable) {
213			GBAudioWriteNR11(&gb->audio, value);
214		} else {
215			if (gb->audio.style == GB_AUDIO_DMG) {
216				GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
217			}
218			value = 0;
219		}
220		break;
221	case REG_NR12:
222		if (gb->audio.enable) {
223			GBAudioWriteNR12(&gb->audio, value);
224		} else {
225			value = 0;
226		}
227		break;
228	case REG_NR13:
229		if (gb->audio.enable) {
230			GBAudioWriteNR13(&gb->audio, value);
231		} else {
232			value = 0;
233		}
234		break;
235	case REG_NR14:
236		if (gb->audio.enable) {
237			GBAudioWriteNR14(&gb->audio, value);
238		} else {
239			value = 0;
240		}
241		break;
242	case REG_NR21:
243		if (gb->audio.enable) {
244			GBAudioWriteNR21(&gb->audio, value);
245		} else {
246			if (gb->audio.style == GB_AUDIO_DMG) {
247				GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
248			}
249			value = 0;
250		}
251		break;
252	case REG_NR22:
253		if (gb->audio.enable) {
254			GBAudioWriteNR22(&gb->audio, value);
255		} else {
256			value = 0;
257		}
258		break;
259	case REG_NR23:
260		if (gb->audio.enable) {
261			GBAudioWriteNR23(&gb->audio, value);
262		} else {
263			value = 0;
264		}
265		break;
266	case REG_NR24:
267		if (gb->audio.enable) {
268			GBAudioWriteNR24(&gb->audio, value);
269		} else {
270			value = 0;
271		}
272		break;
273	case REG_NR30:
274		if (gb->audio.enable) {
275			GBAudioWriteNR30(&gb->audio, value);
276		} else {
277			value = 0;
278		}
279		break;
280	case REG_NR31:
281		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
282			GBAudioWriteNR31(&gb->audio, value);
283		} else {
284			value = 0;
285		}
286		break;
287	case REG_NR32:
288		if (gb->audio.enable) {
289			GBAudioWriteNR32(&gb->audio, value);
290		} else {
291			value = 0;
292		}
293		break;
294	case REG_NR33:
295		if (gb->audio.enable) {
296			GBAudioWriteNR33(&gb->audio, value);
297		} else {
298			value = 0;
299		}
300		break;
301	case REG_NR34:
302		if (gb->audio.enable) {
303			GBAudioWriteNR34(&gb->audio, value);
304		} else {
305			value = 0;
306		}
307		break;
308	case REG_NR41:
309		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
310			GBAudioWriteNR41(&gb->audio, value);
311		} else {
312			value = 0;
313		}
314		break;
315	case REG_NR42:
316		if (gb->audio.enable) {
317			GBAudioWriteNR42(&gb->audio, value);
318		} else {
319			value = 0;
320		}
321		break;
322	case REG_NR43:
323		if (gb->audio.enable) {
324			GBAudioWriteNR43(&gb->audio, value);
325		} else {
326			value = 0;
327		}
328		break;
329	case REG_NR44:
330		if (gb->audio.enable) {
331			GBAudioWriteNR44(&gb->audio, value);
332		} else {
333			value = 0;
334		}
335		break;
336	case REG_NR50:
337		if (gb->audio.enable) {
338			GBAudioWriteNR50(&gb->audio, value);
339		} else {
340			value = 0;
341		}
342		break;
343	case REG_NR51:
344		if (gb->audio.enable) {
345			GBAudioWriteNR51(&gb->audio, value);
346		} else {
347			value = 0;
348		}
349		break;
350	case REG_NR52:
351		GBAudioWriteNR52(&gb->audio, value);
352		value &= 0x80;
353		value |= gb->memory.io[REG_NR52] & 0x0F;
354		break;
355	case REG_WAVE_0:
356	case REG_WAVE_1:
357	case REG_WAVE_2:
358	case REG_WAVE_3:
359	case REG_WAVE_4:
360	case REG_WAVE_5:
361	case REG_WAVE_6:
362	case REG_WAVE_7:
363	case REG_WAVE_8:
364	case REG_WAVE_9:
365	case REG_WAVE_A:
366	case REG_WAVE_B:
367	case REG_WAVE_C:
368	case REG_WAVE_D:
369	case REG_WAVE_E:
370	case REG_WAVE_F:
371		if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
372			gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
373		} else if(gb->audio.ch3.readable) {
374			gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
375		}
376		break;
377	case REG_JOYP:
378		if (gb->model == GB_MODEL_SGB) {
379			_writeSGBBits(gb, (value >> 4) & 3);
380		}
381		break;
382	case REG_TIMA:
383	case REG_TMA:
384		// Handled transparently by the registers
385		break;
386	case REG_TAC:
387		value = GBTimerUpdateTAC(&gb->timer, value);
388		break;
389	case REG_IF:
390		gb->memory.io[REG_IF] = value | 0xE0;
391		GBUpdateIRQs(gb);
392		return;
393	case REG_LCDC:
394		// TODO: handle GBC differences
395		GBVideoProcessDots(&gb->video, 0);
396		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
397		GBVideoWriteLCDC(&gb->video, value);
398		break;
399	case REG_LYC:
400		GBVideoWriteLYC(&gb->video, value);
401		break;
402	case REG_DMA:
403		GBMemoryDMA(gb, value << 8);
404		break;
405	case REG_SCY:
406	case REG_SCX:
407	case REG_WY:
408	case REG_WX:
409		GBVideoProcessDots(&gb->video, 0);
410		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
411		break;
412	case REG_BGP:
413	case REG_OBP0:
414	case REG_OBP1:
415		GBVideoProcessDots(&gb->video, 0);
416		GBVideoWritePalette(&gb->video, address, value);
417		break;
418	case REG_STAT:
419		GBVideoWriteSTAT(&gb->video, value);
420		value = gb->video.stat;
421		break;
422	case 0x50:
423		GBUnmapBIOS(gb);
424		if (gb->model >= GB_MODEL_CGB && gb->memory.io[REG_UNK4C] < 0x80) {
425			gb->model = GB_MODEL_DMG;
426			GBVideoDisableCGB(&gb->video);
427		}
428		break;
429	case REG_IE:
430		gb->memory.ie = value;
431		GBUpdateIRQs(gb);
432		return;
433	default:
434		if (gb->model >= GB_MODEL_CGB) {
435			switch (address) {
436			case REG_UNK4C:
437				break;
438			case REG_KEY1:
439				value &= 0x1;
440				value |= gb->memory.io[address] & 0x80;
441				break;
442			case REG_VBK:
443				GBVideoSwitchBank(&gb->video, value);
444				break;
445			case REG_HDMA1:
446			case REG_HDMA2:
447			case REG_HDMA3:
448			case REG_HDMA4:
449				// Handled transparently by the registers
450				break;
451			case REG_HDMA5:
452				value = GBMemoryWriteHDMA5(gb, value);
453				break;
454			case REG_BCPS:
455				gb->video.bcpIndex = value & 0x3F;
456				gb->video.bcpIncrement = value & 0x80;
457				gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
458				break;
459			case REG_BCPD:
460				GBVideoProcessDots(&gb->video, 0);
461				GBVideoWritePalette(&gb->video, address, value);
462				return;
463			case REG_OCPS:
464				gb->video.ocpIndex = value & 0x3F;
465				gb->video.ocpIncrement = value & 0x80;
466				gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
467				break;
468			case REG_OCPD:
469				GBVideoProcessDots(&gb->video, 0);
470				GBVideoWritePalette(&gb->video, address, value);
471				return;
472			case REG_SVBK:
473				GBMemorySwitchWramBank(&gb->memory, value);
474				value = gb->memory.wramCurrentBank;
475				break;
476			default:
477				goto failed;
478			}
479			goto success;
480		}
481		failed:
482		mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
483		if (address >= GB_SIZE_IO) {
484			return;
485		}
486		break;
487	}
488	success:
489	gb->memory.io[address] = value;
490}
491
492static uint8_t _readKeys(struct GB* gb) {
493	uint8_t keys = *gb->keySource;
494	switch (gb->memory.io[REG_JOYP] & 0x30) {
495	case 0x30:
496	// TODO: Increment
497		keys = (gb->video.sgbCommandHeader >> 3) == SGB_MLT_REG ? 0xF : 0;
498		break;
499	case 0x20:
500		keys >>= 4;
501		break;
502	case 0x10:
503		break;
504	case 0x00:
505		keys |= keys >> 4;
506		break;
507	}
508	return (0xC0 | (gb->memory.io[REG_JOYP] | 0xF)) ^ (keys & 0xF);
509}
510
511uint8_t GBIORead(struct GB* gb, unsigned address) {
512	switch (address) {
513	case REG_JOYP:
514		return _readKeys(gb);
515	case REG_IE:
516		return gb->memory.ie;
517	case REG_WAVE_0:
518	case REG_WAVE_1:
519	case REG_WAVE_2:
520	case REG_WAVE_3:
521	case REG_WAVE_4:
522	case REG_WAVE_5:
523	case REG_WAVE_6:
524	case REG_WAVE_7:
525	case REG_WAVE_8:
526	case REG_WAVE_9:
527	case REG_WAVE_A:
528	case REG_WAVE_B:
529	case REG_WAVE_C:
530	case REG_WAVE_D:
531	case REG_WAVE_E:
532	case REG_WAVE_F:
533		if (gb->audio.playingCh3) {
534			if (gb->audio.ch3.readable || gb->audio.style != GB_AUDIO_DMG) {
535				return gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1];
536			} else {
537				return 0xFF;
538			}
539		} else {
540			return gb->audio.ch3.wavedata8[address - REG_WAVE_0];
541		}
542		break;
543	case REG_SB:
544	case REG_SC:
545	case REG_IF:
546	case REG_NR10:
547	case REG_NR11:
548	case REG_NR12:
549	case REG_NR14:
550	case REG_NR21:
551	case REG_NR22:
552	case REG_NR24:
553	case REG_NR30:
554	case REG_NR32:
555	case REG_NR34:
556	case REG_NR41:
557	case REG_NR42:
558	case REG_NR43:
559	case REG_NR44:
560	case REG_NR50:
561	case REG_NR51:
562	case REG_NR52:
563	case REG_DIV:
564	case REG_TIMA:
565	case REG_TMA:
566	case REG_TAC:
567	case REG_STAT:
568	case REG_LCDC:
569	case REG_SCY:
570	case REG_SCX:
571	case REG_LY:
572	case REG_LYC:
573	case REG_BGP:
574	case REG_OBP0:
575	case REG_OBP1:
576	case REG_WY:
577	case REG_WX:
578		// Handled transparently by the registers
579		break;
580	default:
581		if (gb->model >= GB_MODEL_CGB) {
582			switch (address) {
583			case REG_KEY1:
584			case REG_VBK:
585			case REG_HDMA1:
586			case REG_HDMA2:
587			case REG_HDMA3:
588			case REG_HDMA4:
589			case REG_HDMA5:
590			case REG_BCPS:
591			case REG_BCPD:
592			case REG_OCPS:
593			case REG_OCPD:
594			case REG_SVBK:
595				// Handled transparently by the registers
596				goto success;
597			case REG_DMA:
598				mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
599				return 0;
600			default:
601				break;
602			}
603		}
604		mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
605		return 0xFF;
606	}
607	success:
608	return gb->memory.io[address] | _registerMask[address];
609}
610
611void GBTestKeypadIRQ(struct GB* gb) {
612	if (_readKeys(gb)) {
613		gb->memory.io[REG_IF] |= (1 << GB_IRQ_KEYPAD);
614		GBUpdateIRQs(gb);
615	}
616}
617
618struct GBSerializedState;
619void GBIOSerialize(const struct GB* gb, struct GBSerializedState* state) {
620	memcpy(state->io, gb->memory.io, GB_SIZE_IO);
621	state->ie = gb->memory.ie;
622}
623
624void GBIODeserialize(struct GB* gb, const struct GBSerializedState* state) {
625	memcpy(gb->memory.io, state->io, GB_SIZE_IO);
626	gb->memory.ie = state->ie;
627
628	if (GBAudioEnableGetEnable(*gb->audio.nr52)) {
629		GBIOWrite(gb, REG_NR10, gb->memory.io[REG_NR10]);
630		GBIOWrite(gb, REG_NR11, gb->memory.io[REG_NR11]);
631		GBIOWrite(gb, REG_NR12, gb->memory.io[REG_NR12]);
632		GBIOWrite(gb, REG_NR13, gb->memory.io[REG_NR13]);
633		gb->audio.ch1.control.frequency &= 0xFF;
634		gb->audio.ch1.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR14] << 8);
635		gb->audio.ch1.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR14] << 8);
636		GBIOWrite(gb, REG_NR21, gb->memory.io[REG_NR21]);
637		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR22]);
638		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR23]);
639		gb->audio.ch2.control.frequency &= 0xFF;
640		gb->audio.ch2.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR24] << 8);
641		gb->audio.ch2.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR24] << 8);
642		GBIOWrite(gb, REG_NR30, gb->memory.io[REG_NR30]);
643		GBIOWrite(gb, REG_NR31, gb->memory.io[REG_NR31]);
644		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR32]);
645		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR33]);
646		gb->audio.ch3.rate &= 0xFF;
647		gb->audio.ch3.rate |= GBAudioRegisterControlGetRate(gb->memory.io[REG_NR34] << 8);
648		gb->audio.ch3.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR34] << 8);
649		GBIOWrite(gb, REG_NR41, gb->memory.io[REG_NR41]);
650		GBIOWrite(gb, REG_NR42, gb->memory.io[REG_NR42]);
651		GBIOWrite(gb, REG_NR43, gb->memory.io[REG_NR43]);
652		gb->audio.ch4.stop = GBAudioRegisterNoiseControlGetStop(gb->memory.io[REG_NR44]);
653		GBIOWrite(gb, REG_NR50, gb->memory.io[REG_NR50]);
654		GBIOWrite(gb, REG_NR51, gb->memory.io[REG_NR51]);
655	}
656
657	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_LCDC, state->io[REG_LCDC]);
658	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCY, state->io[REG_SCY]);
659	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCX, state->io[REG_SCX]);
660	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WY, state->io[REG_WY]);
661	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WX, state->io[REG_WX]);
662	if (gb->model == GB_MODEL_SGB) {
663		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_BGP, state->io[REG_BGP]);
664		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP0, state->io[REG_OBP0]);
665		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP1, state->io[REG_OBP1]);
666	}
667	gb->video.stat = state->io[REG_STAT];
668}