all repos — mgba @ 420a15a84151065982c1170b0983f136e9b1cddb

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 = -1;
110		memset(gb->sgbPacket, 0, sizeof(gb->sgbPacket));
111	}
112	if (bits == gb->currentSgbBits) {
113		return;
114	}
115	gb->currentSgbBits = bits;
116	if (bits == 3) {
117		gb->sgbCurrentController = (gb->sgbCurrentController + 1) & gb->sgbControllers;
118	}
119	if (gb->sgbBit == 128 && bits == 2) {
120		GBVideoWriteSGBPacket(&gb->video, gb->sgbPacket);
121		++gb->sgbBit;
122	}
123	if (gb->sgbBit >= 128) {
124		return;
125	}
126	switch (bits) {
127	case 1:
128		if (gb->sgbBit < 0) {
129			return;
130		}
131		gb->sgbPacket[gb->sgbBit >> 3] |= 1 << (gb->sgbBit & 7);
132		break;
133	case 3:
134		++gb->sgbBit;
135	default:
136		break;
137	}
138}
139
140void GBIOInit(struct GB* gb) {
141	memset(gb->memory.io, 0, sizeof(gb->memory.io));
142}
143
144void GBIOReset(struct GB* gb) {
145	memset(gb->memory.io, 0, sizeof(gb->memory.io));
146
147	GBIOWrite(gb, REG_TIMA, 0);
148	GBIOWrite(gb, REG_TMA, 0);
149	GBIOWrite(gb, REG_TAC, 0);
150	GBIOWrite(gb, REG_IF, 1);
151	GBIOWrite(gb, REG_NR52, 0xF1);
152	GBIOWrite(gb, REG_NR14, 0x3F);
153	GBIOWrite(gb, REG_NR10, 0x80);
154	GBIOWrite(gb, REG_NR11, 0xBF);
155	GBIOWrite(gb, REG_NR12, 0xF3);
156	GBIOWrite(gb, REG_NR13, 0xF3);
157	GBIOWrite(gb, REG_NR24, 0x3F);
158	GBIOWrite(gb, REG_NR21, 0x3F);
159	GBIOWrite(gb, REG_NR22, 0x00);
160	GBIOWrite(gb, REG_NR34, 0x3F);
161	GBIOWrite(gb, REG_NR30, 0x7F);
162	GBIOWrite(gb, REG_NR31, 0xFF);
163	GBIOWrite(gb, REG_NR32, 0x9F);
164	GBIOWrite(gb, REG_NR44, 0x3F);
165	GBIOWrite(gb, REG_NR41, 0xFF);
166	GBIOWrite(gb, REG_NR42, 0x00);
167	GBIOWrite(gb, REG_NR43, 0x00);
168	GBIOWrite(gb, REG_NR50, 0x77);
169	GBIOWrite(gb, REG_NR51, 0xF3);
170	GBIOWrite(gb, REG_LCDC, 0x91);
171	GBIOWrite(gb, REG_SCY, 0x00);
172	GBIOWrite(gb, REG_SCX, 0x00);
173	GBIOWrite(gb, REG_LYC, 0x00);
174	GBIOWrite(gb, REG_BGP, 0xFC);
175	if (gb->model < GB_MODEL_CGB) {
176		GBIOWrite(gb, REG_OBP0, 0xFF);
177		GBIOWrite(gb, REG_OBP1, 0xFF);
178	}
179	GBIOWrite(gb, REG_WY, 0x00);
180	GBIOWrite(gb, REG_WX, 0x00);
181	if (gb->model >= GB_MODEL_CGB) {
182		GBIOWrite(gb, REG_UNK4C, 0);
183		GBIOWrite(gb, REG_JOYP, 0xFF);
184		GBIOWrite(gb, REG_VBK, 0);
185		GBIOWrite(gb, REG_BCPS, 0);
186		GBIOWrite(gb, REG_OCPS, 0);
187		GBIOWrite(gb, REG_SVBK, 1);
188		GBIOWrite(gb, REG_HDMA1, 0xFF);
189		GBIOWrite(gb, REG_HDMA2, 0xFF);
190		GBIOWrite(gb, REG_HDMA3, 0xFF);
191		GBIOWrite(gb, REG_HDMA4, 0xFF);
192		gb->memory.io[REG_HDMA5] = 0xFF;
193	} else if (gb->model == GB_MODEL_SGB) {
194		GBIOWrite(gb, REG_JOYP, 0xFF);
195	}
196	GBIOWrite(gb, REG_IE, 0x00);
197}
198
199void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
200	switch (address) {
201	case REG_SB:
202		GBSIOWriteSB(&gb->sio, value);
203		break;
204	case REG_SC:
205		GBSIOWriteSC(&gb->sio, value);
206		break;
207	case REG_DIV:
208		GBTimerDivReset(&gb->timer);
209		return;
210	case REG_NR10:
211		if (gb->audio.enable) {
212			GBAudioWriteNR10(&gb->audio, value);
213		} else {
214			value = 0;
215		}
216		break;
217	case REG_NR11:
218		if (gb->audio.enable) {
219			GBAudioWriteNR11(&gb->audio, value);
220		} else {
221			if (gb->audio.style == GB_AUDIO_DMG) {
222				GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
223			}
224			value = 0;
225		}
226		break;
227	case REG_NR12:
228		if (gb->audio.enable) {
229			GBAudioWriteNR12(&gb->audio, value);
230		} else {
231			value = 0;
232		}
233		break;
234	case REG_NR13:
235		if (gb->audio.enable) {
236			GBAudioWriteNR13(&gb->audio, value);
237		} else {
238			value = 0;
239		}
240		break;
241	case REG_NR14:
242		if (gb->audio.enable) {
243			GBAudioWriteNR14(&gb->audio, value);
244		} else {
245			value = 0;
246		}
247		break;
248	case REG_NR21:
249		if (gb->audio.enable) {
250			GBAudioWriteNR21(&gb->audio, value);
251		} else {
252			if (gb->audio.style == GB_AUDIO_DMG) {
253				GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
254			}
255			value = 0;
256		}
257		break;
258	case REG_NR22:
259		if (gb->audio.enable) {
260			GBAudioWriteNR22(&gb->audio, value);
261		} else {
262			value = 0;
263		}
264		break;
265	case REG_NR23:
266		if (gb->audio.enable) {
267			GBAudioWriteNR23(&gb->audio, value);
268		} else {
269			value = 0;
270		}
271		break;
272	case REG_NR24:
273		if (gb->audio.enable) {
274			GBAudioWriteNR24(&gb->audio, value);
275		} else {
276			value = 0;
277		}
278		break;
279	case REG_NR30:
280		if (gb->audio.enable) {
281			GBAudioWriteNR30(&gb->audio, value);
282		} else {
283			value = 0;
284		}
285		break;
286	case REG_NR31:
287		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
288			GBAudioWriteNR31(&gb->audio, value);
289		} else {
290			value = 0;
291		}
292		break;
293	case REG_NR32:
294		if (gb->audio.enable) {
295			GBAudioWriteNR32(&gb->audio, value);
296		} else {
297			value = 0;
298		}
299		break;
300	case REG_NR33:
301		if (gb->audio.enable) {
302			GBAudioWriteNR33(&gb->audio, value);
303		} else {
304			value = 0;
305		}
306		break;
307	case REG_NR34:
308		if (gb->audio.enable) {
309			GBAudioWriteNR34(&gb->audio, value);
310		} else {
311			value = 0;
312		}
313		break;
314	case REG_NR41:
315		if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
316			GBAudioWriteNR41(&gb->audio, value);
317		} else {
318			value = 0;
319		}
320		break;
321	case REG_NR42:
322		if (gb->audio.enable) {
323			GBAudioWriteNR42(&gb->audio, value);
324		} else {
325			value = 0;
326		}
327		break;
328	case REG_NR43:
329		if (gb->audio.enable) {
330			GBAudioWriteNR43(&gb->audio, value);
331		} else {
332			value = 0;
333		}
334		break;
335	case REG_NR44:
336		if (gb->audio.enable) {
337			GBAudioWriteNR44(&gb->audio, value);
338		} else {
339			value = 0;
340		}
341		break;
342	case REG_NR50:
343		if (gb->audio.enable) {
344			GBAudioWriteNR50(&gb->audio, value);
345		} else {
346			value = 0;
347		}
348		break;
349	case REG_NR51:
350		if (gb->audio.enable) {
351			GBAudioWriteNR51(&gb->audio, value);
352		} else {
353			value = 0;
354		}
355		break;
356	case REG_NR52:
357		GBAudioWriteNR52(&gb->audio, value);
358		value &= 0x80;
359		value |= gb->memory.io[REG_NR52] & 0x0F;
360		break;
361	case REG_WAVE_0:
362	case REG_WAVE_1:
363	case REG_WAVE_2:
364	case REG_WAVE_3:
365	case REG_WAVE_4:
366	case REG_WAVE_5:
367	case REG_WAVE_6:
368	case REG_WAVE_7:
369	case REG_WAVE_8:
370	case REG_WAVE_9:
371	case REG_WAVE_A:
372	case REG_WAVE_B:
373	case REG_WAVE_C:
374	case REG_WAVE_D:
375	case REG_WAVE_E:
376	case REG_WAVE_F:
377		if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
378			gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
379		} else if(gb->audio.ch3.readable) {
380			gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
381		}
382		break;
383	case REG_JOYP:
384		if (gb->model == GB_MODEL_SGB) {
385			_writeSGBBits(gb, (value >> 4) & 3);
386		}
387		break;
388	case REG_TIMA:
389		if (value && mTimingUntil(&gb->timing, &gb->timer.irq) > 1) {
390			mTimingDeschedule(&gb->timing, &gb->timer.irq);
391		}
392		if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
393			return;
394		}
395		break;
396	case REG_TMA:
397		if (mTimingUntil(&gb->timing, &gb->timer.irq) == -1) {
398			gb->memory.io[REG_TIMA] = value;
399		}
400		break;
401	case REG_TAC:
402		value = GBTimerUpdateTAC(&gb->timer, value);
403		break;
404	case REG_IF:
405		gb->memory.io[REG_IF] = value | 0xE0;
406		GBUpdateIRQs(gb);
407		return;
408	case REG_LCDC:
409		// TODO: handle GBC differences
410		GBVideoProcessDots(&gb->video, 0);
411		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
412		GBVideoWriteLCDC(&gb->video, value);
413		break;
414	case REG_LYC:
415		GBVideoWriteLYC(&gb->video, value);
416		break;
417	case REG_DMA:
418		GBMemoryDMA(gb, value << 8);
419		break;
420	case REG_SCY:
421	case REG_SCX:
422	case REG_WY:
423	case REG_WX:
424		GBVideoProcessDots(&gb->video, 0);
425		value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
426		break;
427	case REG_BGP:
428	case REG_OBP0:
429	case REG_OBP1:
430		GBVideoProcessDots(&gb->video, 0);
431		GBVideoWritePalette(&gb->video, address, value);
432		break;
433	case REG_STAT:
434		GBVideoWriteSTAT(&gb->video, value);
435		value = gb->video.stat;
436		break;
437	case 0x50:
438		GBUnmapBIOS(gb);
439		if (gb->model >= GB_MODEL_CGB && gb->memory.io[REG_UNK4C] < 0x80) {
440			gb->model = GB_MODEL_DMG;
441			GBVideoDisableCGB(&gb->video);
442		}
443		break;
444	case REG_IE:
445		gb->memory.ie = value;
446		GBUpdateIRQs(gb);
447		return;
448	default:
449		if (gb->model >= GB_MODEL_CGB) {
450			switch (address) {
451			case REG_UNK4C:
452				break;
453			case REG_KEY1:
454				value &= 0x1;
455				value |= gb->memory.io[address] & 0x80;
456				break;
457			case REG_VBK:
458				GBVideoSwitchBank(&gb->video, value);
459				break;
460			case REG_HDMA1:
461			case REG_HDMA2:
462			case REG_HDMA3:
463			case REG_HDMA4:
464				// Handled transparently by the registers
465				break;
466			case REG_HDMA5:
467				value = GBMemoryWriteHDMA5(gb, value);
468				break;
469			case REG_BCPS:
470				gb->video.bcpIndex = value & 0x3F;
471				gb->video.bcpIncrement = value & 0x80;
472				gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
473				break;
474			case REG_BCPD:
475				GBVideoProcessDots(&gb->video, 0);
476				GBVideoWritePalette(&gb->video, address, value);
477				return;
478			case REG_OCPS:
479				gb->video.ocpIndex = value & 0x3F;
480				gb->video.ocpIncrement = value & 0x80;
481				gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
482				break;
483			case REG_OCPD:
484				GBVideoProcessDots(&gb->video, 0);
485				GBVideoWritePalette(&gb->video, address, value);
486				return;
487			case REG_SVBK:
488				GBMemorySwitchWramBank(&gb->memory, value);
489				value = gb->memory.wramCurrentBank;
490				break;
491			default:
492				goto failed;
493			}
494			goto success;
495		}
496		failed:
497		mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
498		if (address >= GB_SIZE_IO) {
499			return;
500		}
501		break;
502	}
503	success:
504	gb->memory.io[address] = value;
505}
506
507static uint8_t _readKeys(struct GB* gb) {
508	uint8_t keys = *gb->keySource;
509	if (gb->sgbCurrentController != 0) {
510		keys = 0;
511	}
512	switch (gb->memory.io[REG_JOYP] & 0x30) {
513	case 0x30:
514	// TODO: Increment
515		keys = (gb->video.sgbCommandHeader >> 3) == SGB_MLT_REQ ? 0xF - gb->sgbCurrentController : 0;
516		break;
517	case 0x20:
518		keys >>= 4;
519		break;
520	case 0x10:
521		break;
522	case 0x00:
523		keys |= keys >> 4;
524		break;
525	}
526	return (0xC0 | (gb->memory.io[REG_JOYP] | 0xF)) ^ (keys & 0xF);
527}
528
529uint8_t GBIORead(struct GB* gb, unsigned address) {
530	switch (address) {
531	case REG_JOYP:
532		return _readKeys(gb);
533	case REG_IE:
534		return gb->memory.ie;
535	case REG_WAVE_0:
536	case REG_WAVE_1:
537	case REG_WAVE_2:
538	case REG_WAVE_3:
539	case REG_WAVE_4:
540	case REG_WAVE_5:
541	case REG_WAVE_6:
542	case REG_WAVE_7:
543	case REG_WAVE_8:
544	case REG_WAVE_9:
545	case REG_WAVE_A:
546	case REG_WAVE_B:
547	case REG_WAVE_C:
548	case REG_WAVE_D:
549	case REG_WAVE_E:
550	case REG_WAVE_F:
551		if (gb->audio.playingCh3) {
552			if (gb->audio.ch3.readable || gb->audio.style != GB_AUDIO_DMG) {
553				return gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1];
554			} else {
555				return 0xFF;
556			}
557		} else {
558			return gb->audio.ch3.wavedata8[address - REG_WAVE_0];
559		}
560		break;
561	case REG_SB:
562	case REG_SC:
563	case REG_IF:
564	case REG_NR10:
565	case REG_NR11:
566	case REG_NR12:
567	case REG_NR14:
568	case REG_NR21:
569	case REG_NR22:
570	case REG_NR24:
571	case REG_NR30:
572	case REG_NR32:
573	case REG_NR34:
574	case REG_NR41:
575	case REG_NR42:
576	case REG_NR43:
577	case REG_NR44:
578	case REG_NR50:
579	case REG_NR51:
580	case REG_NR52:
581	case REG_DIV:
582	case REG_TIMA:
583	case REG_TMA:
584	case REG_TAC:
585	case REG_STAT:
586	case REG_LCDC:
587	case REG_SCY:
588	case REG_SCX:
589	case REG_LY:
590	case REG_LYC:
591	case REG_BGP:
592	case REG_OBP0:
593	case REG_OBP1:
594	case REG_WY:
595	case REG_WX:
596		// Handled transparently by the registers
597		break;
598	default:
599		if (gb->model >= GB_MODEL_CGB) {
600			switch (address) {
601			case REG_KEY1:
602			case REG_VBK:
603			case REG_HDMA1:
604			case REG_HDMA2:
605			case REG_HDMA3:
606			case REG_HDMA4:
607			case REG_HDMA5:
608			case REG_BCPS:
609			case REG_BCPD:
610			case REG_OCPS:
611			case REG_OCPD:
612			case REG_SVBK:
613				// Handled transparently by the registers
614				goto success;
615			case REG_DMA:
616				mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
617				return 0;
618			default:
619				break;
620			}
621		}
622		mLOG(GB_IO, STUB, "Reading from unknown register FF%02X", address);
623		return 0xFF;
624	}
625	success:
626	return gb->memory.io[address] | _registerMask[address];
627}
628
629void GBTestKeypadIRQ(struct GB* gb) {
630	if (_readKeys(gb)) {
631		gb->memory.io[REG_IF] |= (1 << GB_IRQ_KEYPAD);
632		GBUpdateIRQs(gb);
633	}
634}
635
636struct GBSerializedState;
637void GBIOSerialize(const struct GB* gb, struct GBSerializedState* state) {
638	memcpy(state->io, gb->memory.io, GB_SIZE_IO);
639	state->ie = gb->memory.ie;
640}
641
642void GBIODeserialize(struct GB* gb, const struct GBSerializedState* state) {
643	memcpy(gb->memory.io, state->io, GB_SIZE_IO);
644	gb->memory.ie = state->ie;
645
646	if (GBAudioEnableGetEnable(*gb->audio.nr52)) {
647		GBIOWrite(gb, REG_NR10, gb->memory.io[REG_NR10]);
648		GBIOWrite(gb, REG_NR11, gb->memory.io[REG_NR11]);
649		GBIOWrite(gb, REG_NR12, gb->memory.io[REG_NR12]);
650		GBIOWrite(gb, REG_NR13, gb->memory.io[REG_NR13]);
651		gb->audio.ch1.control.frequency &= 0xFF;
652		gb->audio.ch1.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR14] << 8);
653		gb->audio.ch1.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR14] << 8);
654		GBIOWrite(gb, REG_NR21, gb->memory.io[REG_NR21]);
655		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR22]);
656		GBIOWrite(gb, REG_NR22, gb->memory.io[REG_NR23]);
657		gb->audio.ch2.control.frequency &= 0xFF;
658		gb->audio.ch2.control.frequency |= GBAudioRegisterControlGetFrequency(gb->memory.io[REG_NR24] << 8);
659		gb->audio.ch2.control.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR24] << 8);
660		GBIOWrite(gb, REG_NR30, gb->memory.io[REG_NR30]);
661		GBIOWrite(gb, REG_NR31, gb->memory.io[REG_NR31]);
662		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR32]);
663		GBIOWrite(gb, REG_NR32, gb->memory.io[REG_NR33]);
664		gb->audio.ch3.rate &= 0xFF;
665		gb->audio.ch3.rate |= GBAudioRegisterControlGetRate(gb->memory.io[REG_NR34] << 8);
666		gb->audio.ch3.stop = GBAudioRegisterControlGetStop(gb->memory.io[REG_NR34] << 8);
667		GBIOWrite(gb, REG_NR41, gb->memory.io[REG_NR41]);
668		GBIOWrite(gb, REG_NR42, gb->memory.io[REG_NR42]);
669		GBIOWrite(gb, REG_NR43, gb->memory.io[REG_NR43]);
670		gb->audio.ch4.stop = GBAudioRegisterNoiseControlGetStop(gb->memory.io[REG_NR44]);
671		GBIOWrite(gb, REG_NR50, gb->memory.io[REG_NR50]);
672		GBIOWrite(gb, REG_NR51, gb->memory.io[REG_NR51]);
673	}
674
675	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_LCDC, state->io[REG_LCDC]);
676	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCY, state->io[REG_SCY]);
677	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_SCX, state->io[REG_SCX]);
678	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WY, state->io[REG_WY]);
679	gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_WX, state->io[REG_WX]);
680	if (gb->model == GB_MODEL_SGB) {
681		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_BGP, state->io[REG_BGP]);
682		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP0, state->io[REG_OBP0]);
683		gb->video.renderer->writeVideoRegister(gb->video.renderer, REG_OBP1, state->io[REG_OBP1]);
684	}
685	gb->video.stat = state->io[REG_STAT];
686}