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tests: send error_report to test log
[qemu/kevin.git] / hw / audio / gusemu_hal.c
blob973d6b9f4f491586bd533c6919ccc4e8e8a3a782
1 /*
2 * GUSEMU32 - bus interface part
3 *
4 * Copyright (C) 2000-2007 Tibor "TS" Schütz
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 /*
26 * TODO: check mixer: see 7.20 of sdk for panning pos (applies to all gus models?)?
27 */
28
29 #include "qemu/osdep.h"
30 #include "gustate.h"
31 #include "gusemu.h"
32
33 #define GUSregb(position) (* (gusptr+(position)))
34 #define GUSregw(position) (*(GUSword *) (gusptr+(position)))
35 #define GUSregd(position) (*(GUSdword *)(gusptr+(position)))
36
37 /* size given in bytes */
38 unsigned int gus_read(GUSEmuState * state, int port, int size)
39 {
40 int value_read = 0;
41
42 GUSbyte *gusptr;
43 gusptr = state->gusdatapos;
44 GUSregd(portaccesses)++;
45
46 switch (port & 0xff0f)
47 {
48 /* MixerCtrlReg (read not supported on GUS classic) */
49 /* case 0x200: return GUSregb(MixerCtrlReg2x0); */
50 case 0x206: /* IRQstatReg / SB2x6IRQ */
51 /* adlib/sb bits set in port handlers */
52 /* timer/voice bits set in gus_irqgen() */
53 /* dma bit set in gus_dma_transferdata */
54 /* midi not implemented yet */
55 return GUSregb(IRQStatReg2x6);
56 /* case 0x308: */ /* AdLib388 */
57 case 0x208:
58 if (GUSregb(GUS45TimerCtrl) & 1)
59 return GUSregb(TimerStatus2x8);
60 return GUSregb(AdLibStatus2x8); /* AdLibStatus */
61 case 0x309: /* AdLib389 */
62 case 0x209:
63 return GUSregb(AdLibData2x9); /* AdLibData */
64 case 0x20A:
65 return GUSregb(AdLibCommand2xA); /* AdLib2x8_2xA */
66
67 #if 0
68 case 0x20B: /* GUS hidden registers (read not supported on GUS classic) */
69 switch (GUSregb(RegCtrl_2xF) & 0x07)
70 {
71 case 0: /* IRQ/DMA select */
72 if (GUSregb(MixerCtrlReg2x0) & 0x40)
73 return GUSregb(IRQ_2xB); /* control register select bit */
74 else
75 return GUSregb(DMA_2xB);
76 /* case 1-5: */ /* general purpose emulation regs */
77 /* return ... */ /* + status reset reg (write only) */
78 case 6:
79 return GUSregb(Jumper_2xB); /* Joystick/MIDI enable (JumperReg) */
80 default:;
81 }
82 break;
83 #endif
84
85 case 0x20C: /* SB2xCd */
86 value_read = GUSregb(SB2xCd);
87 if (GUSregb(StatRead_2xF) & 0x20)
88 GUSregb(SB2xCd) ^= 0x80; /* toggle MSB on read */
89 return value_read;
90 /* case 0x20D: */ /* SB2xD is write only -> 2xE writes to it*/
91 case 0x20E:
92 if (GUSregb(RegCtrl_2xF) & 0x80) /* 2xE read IRQ enabled? */
93 {
94 GUSregb(StatRead_2xF) |= 0x80;
95 GUS_irqrequest(state, state->gusirq, 1);
96 }
97 return GUSregb(SB2xE); /* SB2xE */
98 case 0x20F: /* StatRead_2xF */
99 /*set/clear fixed bits */
100 /*value_read = (GUSregb(StatRead_2xF) & 0xf9)|1; */ /*(LSB not set on GUS classic!)*/
101 value_read = (GUSregb(StatRead_2xF) & 0xf9);
102 if (GUSregb(MixerCtrlReg2x0) & 0x08)
103 value_read |= 2; /* DMA/IRQ enabled flag */
104 return value_read;
105 /* case 0x300: */ /* MIDI (not implemented) */
106 /* case 0x301: */ /* MIDI (not implemented) */
107 case 0x302:
108 return GUSregb(VoiceSelReg3x2); /* VoiceSelReg */
109 case 0x303:
110 return GUSregb(FunkSelReg3x3); /* FunkSelReg */
111 case 0x304: /* DataRegLoByte3x4 + DataRegWord3x4 */
112 case 0x305: /* DataRegHiByte3x5 */
113 switch (GUSregb(FunkSelReg3x3))
114 {
115 /* common functions */
116 case 0x41: /* DramDMAContrReg */
117 value_read = GUSregb(GUS41DMACtrl); /* &0xfb */
118 GUSregb(GUS41DMACtrl) &= 0xbb;
119 if (state->gusdma >= 4)
120 value_read |= 0x04;
121 if (GUSregb(IRQStatReg2x6) & 0x80)
122 {
123 value_read |= 0x40;
124 GUSregb(IRQStatReg2x6) &= 0x7f;
125 if (!GUSregb(IRQStatReg2x6))
126 GUS_irqclear(state, state->gusirq);
127 }
128 return (GUSbyte) value_read;
129 /* DramDMAmemPosReg */
130 /* case 0x42: value_read=GUSregw(GUS42DMAStart); break;*/
131 /* 43h+44h write only */
132 case 0x45:
133 return GUSregb(GUS45TimerCtrl); /* TimerCtrlReg */
134 /* 46h+47h write only */
135 /* 48h: samp freq - write only */
136 case 0x49:
137 return GUSregb(GUS49SampCtrl) & 0xbf; /* SampCtrlReg */
138 /* case 4bh: */ /* joystick trim not supported */
139 /* case 0x4c: return GUSregb(GUS4cReset); */ /* GUSreset: write only*/
140 /* voice specific functions */
141 case 0x80:
142 case 0x81:
143 case 0x82:
144 case 0x83:
145 case 0x84:
146 case 0x85:
147 case 0x86:
148 case 0x87:
149 case 0x88:
150 case 0x89:
151 case 0x8a:
152 case 0x8b:
153 case 0x8c:
154 case 0x8d:
155 {
156 int offset = 2 * (GUSregb(FunkSelReg3x3) & 0x0f);
157 offset += ((int) GUSregb(VoiceSelReg3x2) & 0x1f) << 5; /* = Voice*32 + Funktion*2 */
158 value_read = GUSregw(offset);
159 }
160 break;
161 /* voice unspecific functions */
162 case 0x8e: /* NumVoice */
163 return GUSregb(NumVoices);
164 case 0x8f: /* irqstatreg */
165 /* (pseudo IRQ-FIFO is processed during a gus_write(0x3X3,0x8f)) */
166 return GUSregb(SynVoiceIRQ8f);
167 default:
168 return 0xffff;
169 }
170 if (size == 1)
171 {
172 if ((port & 0xff0f) == 0x305)
173 value_read = value_read >> 8;
174 value_read &= 0xff;
175 }
176 return (GUSword) value_read;
177 /* case 0x306: */ /* Mixer/Version info */
178 /* return 0xff; */ /* Pre 3.6 boards, ICS mixer NOT present */
179 case 0x307: /* DRAMaccess */
180 {
181 GUSbyte *adr;
182 adr = state->himemaddr + (GUSregd(GUSDRAMPOS24bit) & 0xfffff);
183 return *adr;
184 }
185 default:;
186 }
187 return 0xffff;
188 }
189
190 void gus_write(GUSEmuState * state, int port, int size, unsigned int data)
191 {
192 GUSbyte *gusptr;
193 gusptr = state->gusdatapos;
194 GUSregd(portaccesses)++;
195
196 switch (port & 0xff0f)
197 {
198 case 0x200: /* MixerCtrlReg */
199 GUSregb(MixerCtrlReg2x0) = (GUSbyte) data;
200 break;
201 case 0x206: /* IRQstatReg / SB2x6IRQ */
202 if (GUSregb(GUS45TimerCtrl) & 0x20) /* SB IRQ enabled? -> set 2x6IRQ bit */
203 {
204 GUSregb(TimerStatus2x8) |= 0x08;
205 GUSregb(IRQStatReg2x6) = 0x10;
206 GUS_irqrequest(state, state->gusirq, 1);
207 }
208 break;
209 case 0x308: /* AdLib 388h */
210 case 0x208: /* AdLibCommandReg */
211 GUSregb(AdLibCommand2xA) = (GUSbyte) data;
212 break;
213 case 0x309: /* AdLib 389h */
214 case 0x209: /* AdLibDataReg */
215 if ((GUSregb(AdLibCommand2xA) == 0x04) && (!(GUSregb(GUS45TimerCtrl) & 1))) /* GUS auto timer mode enabled? */
216 {
217 if (data & 0x80)
218 GUSregb(TimerStatus2x8) &= 0x1f; /* AdLib IRQ reset? -> clear maskable adl. timer int regs */
219 else
220 GUSregb(TimerDataReg2x9) = (GUSbyte) data;
221 }
222 else
223 {
224 GUSregb(AdLibData2x9) = (GUSbyte) data;
225 if (GUSregb(GUS45TimerCtrl) & 0x02)
226 {
227 GUSregb(TimerStatus2x8) |= 0x01;
228 GUSregb(IRQStatReg2x6) = 0x10;
229 GUS_irqrequest(state, state->gusirq, 1);
230 }
231 }
232 break;
233 case 0x20A:
234 GUSregb(AdLibStatus2x8) = (GUSbyte) data;
235 break; /* AdLibStatus2x8 */
236 case 0x20B: /* GUS hidden registers */
237 switch (GUSregb(RegCtrl_2xF) & 0x7)
238 {
239 case 0:
240 if (GUSregb(MixerCtrlReg2x0) & 0x40)
241 GUSregb(IRQ_2xB) = (GUSbyte) data; /* control register select bit */
242 else
243 GUSregb(DMA_2xB) = (GUSbyte) data;
244 break;
245 /* case 1-4: general purpose emulation regs */
246 case 5: /* clear stat reg 2xF */
247 GUSregb(StatRead_2xF) = 0; /* ToDo: is this identical with GUS classic? */
248 if (!GUSregb(IRQStatReg2x6))
249 GUS_irqclear(state, state->gusirq);
250 break;
251 case 6: /* Jumper reg (Joystick/MIDI enable) */
252 GUSregb(Jumper_2xB) = (GUSbyte) data;
253 break;
254 default:;
255 }
256 break;
257 case 0x20C: /* SB2xCd */
258 if (GUSregb(GUS45TimerCtrl) & 0x20)
259 {
260 GUSregb(TimerStatus2x8) |= 0x10; /* SB IRQ enabled? -> set 2xCIRQ bit */
261 GUSregb(IRQStatReg2x6) = 0x10;
262 GUS_irqrequest(state, state->gusirq, 1);
263 }
264 case 0x20D: /* SB2xCd no IRQ */
265 GUSregb(SB2xCd) = (GUSbyte) data;
266 break;
267 case 0x20E: /* SB2xE */
268 GUSregb(SB2xE) = (GUSbyte) data;
269 break;
270 case 0x20F:
271 GUSregb(RegCtrl_2xF) = (GUSbyte) data;
272 break; /* CtrlReg2xF */
273 case 0x302: /* VoiceSelReg */
274 GUSregb(VoiceSelReg3x2) = (GUSbyte) data;
275 break;
276 case 0x303: /* FunkSelReg */
277 GUSregb(FunkSelReg3x3) = (GUSbyte) data;
278 if ((GUSbyte) data == 0x8f) /* set irqstatreg, get voicereg and clear IRQ */
279 {
280 int voice;
281 if (GUSregd(voicewavetableirq)) /* WavetableIRQ */
282 {
283 for (voice = 0; voice < 31; voice++)
284 {
285 if (GUSregd(voicewavetableirq) & (1 << voice))
286 {
287 GUSregd(voicewavetableirq) ^= (1 << voice); /* clear IRQ bit */
288 GUSregb(voice << 5) &= 0x7f; /* clear voice reg irq bit */
289 if (!GUSregd(voicewavetableirq))
290 GUSregb(IRQStatReg2x6) &= 0xdf;
291 if (!GUSregb(IRQStatReg2x6))
292 GUS_irqclear(state, state->gusirq);
293 GUSregb(SynVoiceIRQ8f) = voice | 0x60; /* (bit==0 => IRQ wartend) */
294 return;
295 }
296 }
297 }
298 else if (GUSregd(voicevolrampirq)) /* VolRamp IRQ */
299 {
300 for (voice = 0; voice < 31; voice++)
301 {
302 if (GUSregd(voicevolrampirq) & (1 << voice))
303 {
304 GUSregd(voicevolrampirq) ^= (1 << voice); /* clear IRQ bit */
305 GUSregb((voice << 5) + VSRVolRampControl) &= 0x7f; /* clear voice volume reg irq bit */
306 if (!GUSregd(voicevolrampirq))
307 GUSregb(IRQStatReg2x6) &= 0xbf;
308 if (!GUSregb(IRQStatReg2x6))
309 GUS_irqclear(state, state->gusirq);
310 GUSregb(SynVoiceIRQ8f) = voice | 0x80; /* (bit==0 => IRQ wartend) */
311 return;
312 }
313 }
314 }
315 GUSregb(SynVoiceIRQ8f) = 0xe8; /* kein IRQ wartet */
316 }
317 break;
318 case 0x304:
319 case 0x305:
320 {
321 GUSword writedata = (GUSword) data;
322 GUSword readmask = 0x0000;
323 if (size == 1)
324 {
325 readmask = 0xff00;
326 writedata &= 0xff;
327 if ((port & 0xff0f) == 0x305)
328 {
329 writedata = (GUSword) (writedata << 8);
330 readmask = 0x00ff;
331 }
332 }
333 switch (GUSregb(FunkSelReg3x3))
334 {
335 /* voice specific functions */
336 case 0x00:
337 case 0x01:
338 case 0x02:
339 case 0x03:
340 case 0x04:
341 case 0x05:
342 case 0x06:
343 case 0x07:
344 case 0x08:
345 case 0x09:
346 case 0x0a:
347 case 0x0b:
348 case 0x0c:
349 case 0x0d:
350 {
351 int offset;
352 if (!(GUSregb(GUS4cReset) & 0x01))
353 break; /* reset flag active? */
354 offset = 2 * (GUSregb(FunkSelReg3x3) & 0x0f);
355 offset += (GUSregb(VoiceSelReg3x2) & 0x1f) << 5; /* = Voice*32 + Funktion*2 */
356 GUSregw(offset) = (GUSword) ((GUSregw(offset) & readmask) | writedata);
357 }
358 break;
359 /* voice unspecific functions */
360 case 0x0e: /* NumVoices */
361 GUSregb(NumVoices) = (GUSbyte) data;
362 break;
363 /* case 0x0f: */ /* read only */
364 /* common functions */
365 case 0x41: /* DramDMAContrReg */
366 GUSregb(GUS41DMACtrl) = (GUSbyte) data;
367 if (data & 0x01)
368 GUS_dmarequest(state);
369 break;
370 case 0x42: /* DramDMAmemPosReg */
371 GUSregw(GUS42DMAStart) = (GUSregw(GUS42DMAStart) & readmask) | writedata;
372 GUSregb(GUS50DMAHigh) &= 0xf; /* compatibility stuff... */
373 break;
374 case 0x43: /* DRAMaddrLo */
375 GUSregd(GUSDRAMPOS24bit) =
376 (GUSregd(GUSDRAMPOS24bit) & (readmask | 0xff0000)) | writedata;
377 break;
378 case 0x44: /* DRAMaddrHi */
379 GUSregd(GUSDRAMPOS24bit) =
380 (GUSregd(GUSDRAMPOS24bit) & 0xffff) | ((data & 0x0f) << 16);
381 break;
382 case 0x45: /* TCtrlReg */
383 GUSregb(GUS45TimerCtrl) = (GUSbyte) data;
384 if (!(data & 0x20))
385 GUSregb(TimerStatus2x8) &= 0xe7; /* sb IRQ dis? -> clear 2x8/2xC sb IRQ flags */
386 if (!(data & 0x02))
387 GUSregb(TimerStatus2x8) &= 0xfe; /* adlib data IRQ dis? -> clear 2x8 adlib IRQ flag */
388 if (!(GUSregb(TimerStatus2x8) & 0x19))
389 GUSregb(IRQStatReg2x6) &= 0xef; /* 0xe6; $$clear IRQ if both IRQ bits are inactive or cleared */
390 /* catch up delayed timer IRQs: */
391 if ((GUSregw(TimerIRQs) > 1) && (GUSregb(TimerDataReg2x9) & 3))
392 {
393 if (GUSregb(TimerDataReg2x9) & 1) /* start timer 1 (80us decrement rate) */
394 {
395 if (!(GUSregb(TimerDataReg2x9) & 0x40))
396 GUSregb(TimerStatus2x8) |= 0xc0; /* maskable bits */
397 if (data & 4) /* timer1 irq enable */
398 {
399 GUSregb(TimerStatus2x8) |= 4; /* nonmaskable bit */
400 GUSregb(IRQStatReg2x6) |= 4; /* timer 1 irq pending */
401 }
402 }
403 if (GUSregb(TimerDataReg2x9) & 2) /* start timer 2 (320us decrement rate) */
404 {
405 if (!(GUSregb(TimerDataReg2x9) & 0x20))
406 GUSregb(TimerStatus2x8) |= 0xa0; /* maskable bits */
407 if (data & 8) /* timer2 irq enable */
408 {
409 GUSregb(TimerStatus2x8) |= 2; /* nonmaskable bit */
410 GUSregb(IRQStatReg2x6) |= 8; /* timer 2 irq pending */
411 }
412 }
413 GUSregw(TimerIRQs)--;
414 if (GUSregw(BusyTimerIRQs) > 1)
415 GUSregw(BusyTimerIRQs)--;
416 else
417 GUSregw(BusyTimerIRQs) =
418 GUS_irqrequest(state, state->gusirq, GUSregw(TimerIRQs));
419 }
420 else
421 GUSregw(TimerIRQs) = 0;
422
423 if (!(data & 0x04))
424 {
425 GUSregb(TimerStatus2x8) &= 0xfb; /* clear non-maskable timer1 bit */
426 GUSregb(IRQStatReg2x6) &= 0xfb;
427 }
428 if (!(data & 0x08))
429 {
430 GUSregb(TimerStatus2x8) &= 0xfd; /* clear non-maskable timer2 bit */
431 GUSregb(IRQStatReg2x6) &= 0xf7;
432 }
433 if (!GUSregb(IRQStatReg2x6))
434 GUS_irqclear(state, state->gusirq);
435 break;
436 case 0x46: /* Counter1 */
437 GUSregb(GUS46Counter1) = (GUSbyte) data;
438 break;
439 case 0x47: /* Counter2 */
440 GUSregb(GUS47Counter2) = (GUSbyte) data;
441 break;
442 /* case 0x48: */ /* sampling freq reg not emulated (same as interwave) */
443 case 0x49: /* SampCtrlReg */
444 GUSregb(GUS49SampCtrl) = (GUSbyte) data;
445 break;
446 /* case 0x4b: */ /* joystick trim not emulated */
447 case 0x4c: /* GUSreset */
448 GUSregb(GUS4cReset) = (GUSbyte) data;
449 if (!(GUSregb(GUS4cReset) & 1)) /* reset... */
450 {
451 GUSregd(voicewavetableirq) = 0;
452 GUSregd(voicevolrampirq) = 0;
453 GUSregw(TimerIRQs) = 0;
454 GUSregw(BusyTimerIRQs) = 0;
455 GUSregb(NumVoices) = 0xcd;
456 GUSregb(IRQStatReg2x6) = 0;
457 GUSregb(TimerStatus2x8) = 0;
458 GUSregb(AdLibData2x9) = 0;
459 GUSregb(TimerDataReg2x9) = 0;
460 GUSregb(GUS41DMACtrl) = 0;
461 GUSregb(GUS45TimerCtrl) = 0;
462 GUSregb(GUS49SampCtrl) = 0;
463 GUSregb(GUS4cReset) &= 0xf9; /* clear IRQ and DAC enable bits */
464 GUS_irqclear(state, state->gusirq);
465 }
466 /* IRQ enable bit checked elsewhere */
467 /* EnableDAC bit may be used by external callers */
468 break;
469 }
470 }
471 break;
472 case 0x307: /* DRAMaccess */
473 {
474 GUSbyte *adr;
475 adr = state->himemaddr + (GUSregd(GUSDRAMPOS24bit) & 0xfffff);
476 *adr = (GUSbyte) data;
477 }
478 break;
479 }
480 }
481
482 /* Attention when breaking up a single DMA transfer to multiple ones:
483 * it may lead to multiple terminal count interrupts and broken transfers:
484 *
485 * 1. Whenever you transfer a piece of data, the gusemu callback is invoked
486 * 2. The callback may generate a TC irq (if the register was set up to do so)
487 * 3. The irq may result in the program using the GUS to reprogram the GUS
488 *
489 * Some programs also decide to upload by just checking if TC occurs
490 * (via interrupt or a cleared GUS dma flag)
491 * and then start the next transfer, without checking DMA state
492 *
493 * Thus: Always make sure to set the TC flag correctly!
494 *
495 * Note that the genuine GUS had a granularity of 16 bytes/words for low/high DMA
496 * while later cards had atomic granularity provided by an additional GUS50DMAHigh register
497 * GUSemu also uses this register to support byte-granular transfers for better compatibility
498 * with emulators other than GUSemu32
499 */
500
501 void gus_dma_transferdata(GUSEmuState * state, char *dma_addr, unsigned int count, int TC)
502 {
503 /* this function gets called by the callback function as soon as a DMA transfer is about to start
504 * dma_addr is a translated address within accessible memory, not the physical one,
505 * count is (real dma count register)+1
506 * note that the amount of bytes transferred is fully determined by values in the DMA registers
507 * do not forget to update DMA states after transferring the entire block:
508 * DREQ cleared & TC asserted after the _whole_ transfer */
509
510 char *srcaddr;
511 char *destaddr;
512 char msbmask = 0;
513 GUSbyte *gusptr;
514 gusptr = state->gusdatapos;
515
516 srcaddr = dma_addr; /* system memory address */
517 {
518 int offset = (GUSregw(GUS42DMAStart) << 4) + (GUSregb(GUS50DMAHigh) & 0xf);
519 if (state->gusdma >= 4)
520 offset = (offset & 0xc0000) + (2 * (offset & 0x1fff0)); /* 16 bit address translation */
521 destaddr = (char *) state->himemaddr + offset; /* wavetable RAM address */
522 }
523
524 GUSregw(GUS42DMAStart) += (GUSword) (count >> 4); /* ToDo: add 16bit GUS page limit? */
525 GUSregb(GUS50DMAHigh) = (GUSbyte) ((count + GUSregb(GUS50DMAHigh)) & 0xf); /* ToDo: add 16bit GUS page limit? */
526
527 if (GUSregb(GUS41DMACtrl) & 0x02) /* direction, 0 := sysram->gusram */
528 {
529 char *tmpaddr = destaddr;
530 destaddr = srcaddr;
531 srcaddr = tmpaddr;
532 }
533
534 if ((GUSregb(GUS41DMACtrl) & 0x80) && (!(GUSregb(GUS41DMACtrl) & 0x02)))
535 msbmask = (const char) 0x80; /* invert MSB */
536 for (; count > 0; count--)
537 {
538 if (GUSregb(GUS41DMACtrl) & 0x40)
539 *(destaddr++) = *(srcaddr++); /* 16 bit lobyte */
540 else
541 *(destaddr++) = (msbmask ^ (*(srcaddr++))); /* 8 bit */
542 if (state->gusdma >= 4)
543 *(destaddr++) = (msbmask ^ (*(srcaddr++))); /* 16 bit hibyte */
544 }
545
546 if (TC)
547 {
548 (GUSregb(GUS41DMACtrl)) &= 0xfe; /* clear DMA request bit */
549 if (GUSregb(GUS41DMACtrl) & 0x20) /* DMA terminal count IRQ */
550 {
551 GUSregb(IRQStatReg2x6) |= 0x80;
552 GUS_irqrequest(state, state->gusirq, 1);
553 }
554 }
555 }
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