dma.cpp

SFC游戏模拟器 snes9x 1.43 的原代码

				Work = S9xGetPPU (0x2100 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				if (!--count)
					break;
				
				Work = S9xGetPPU (0x2101 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				if (!--count)
					break;
				
				Work = S9xGetPPU (0x2101 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				count--;
				break;
				
			case 4:
				Work = S9xGetPPU (0x2100 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				if (!--count)
					break;
				
				Work = S9xGetPPU (0x2101 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				if (!--count)
					break;
				
				Work = S9xGetPPU (0x2102 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				if (!--count)
					break;
				
				Work = S9xGetPPU (0x2103 + d->BAddress);
				S9xSetByte (Work, (d->ABank << 16) + d->AAddress);
				d->AAddress += inc;
				count--;
				break;
				
			default:
#ifdef DEBUGGER
				if (1) //Settings.TraceDMA)
				{
					sprintf (String, "Unknown DMA transfer mode: %d on channel %d\n",
						d->TransferMode, Channel);
					S9xMessage (S9X_TRACE, S9X_DMA_TRACE, String);
				}
#endif
				count = 0;
				break;
			}
			CHECK_SOUND();
		} while (count);
    }
    
#ifdef SPC700_C
    IAPU.APUExecuting = Settings.APUEnabled;
    APU_EXECUTE ();
#endif
    while (CPU.Cycles > CPU.NextEvent)
		S9xDoHBlankProcessing ();
	S9xUpdateAPUTimer();

	if(Settings.SPC7110&&spc7110_dma)
	{
		if(spc7110_dma&&s7_wrap)
			delete [] spc7110_dma;
	}

update_address:
    // Super Punch-Out requires that the A-BUS address be updated after the
    // DMA transfer.
    Memory.FillRAM[0x4302 + (Channel << 4)] = (uint8) d->AAddress;
    Memory.FillRAM[0x4303 + (Channel << 4)] = d->AAddress >> 8;
	
    // Secret of the Mana requires that the DMA bytes transfer count be set to
    // zero when DMA has completed.
    Memory.FillRAM [0x4305 + (Channel << 4)] = 0;
    Memory.FillRAM [0x4306 + (Channel << 4)] = 0;
	
    DMA[Channel].IndirectAddress = 0;
    d->TransferBytes = 0;
    
    CPU.InDMA = FALSE;


}

void S9xStartHDMA ()
{
    if (Settings.DisableHDMA)
		IPPU.HDMA = 0;
    else
		missing.hdma_this_frame = IPPU.HDMA = Memory.FillRAM [0x420c];
	
	//per anomie timing post
	if(IPPU.HDMA!=0)
	{
		CPU.Cycles+=ONE_CYCLE*3;
		S9xUpdateAPUTimer();
	}
    
	IPPU.HDMAStarted = TRUE;

    for (uint8 i = 0; i < 8; i++)
    {
		if (IPPU.HDMA & (1 << i))
		{
			CPU.Cycles+=SLOW_ONE_CYCLE ;
			S9xUpdateAPUTimer();
			DMA [i].LineCount = 0;
			DMA [i].FirstLine = TRUE;
			DMA [i].Address = DMA [i].AAddress;
			if(DMA[i].HDMAIndirectAddressing)
			{
				CPU.Cycles+=(SLOW_ONE_CYCLE <<2);
				S9xUpdateAPUTimer();
			}
		}
		HDMAMemPointers [i] = NULL;
#ifdef SETA010_HDMA_FROM_CART
		HDMARawPointers [i] = 0;
#endif
    }
}

#ifdef DEBUGGER
void S9xTraceSoundDSP (const char *s, int i1 = 0, int i2 = 0, int i3 = 0,
					   int i4 = 0, int i5 = 0, int i6 = 0, int i7 = 0);
#endif


uint8 S9xDoHDMA (uint8 byte)
{
    struct SDMA *p = &DMA [0];
    
    int d = 0;

	CPU.InDMA = TRUE;
	CPU.Cycles+=ONE_CYCLE*3;
	S9xUpdateAPUTimer();
    for (uint8 mask = 1; mask; mask <<= 1, p++, d++)
	{
		if (byte & mask)
		{
			if (!p->LineCount)
			{
				//remember, InDMA is set.
				//Get/Set incur no charges!
				CPU.Cycles+=SLOW_ONE_CYCLE;
				S9xUpdateAPUTimer();
				uint8 line = S9xGetByte ((p->ABank << 16) + p->Address);
				if (line == 0x80)
				{
					p->Repeat = TRUE;
					p->LineCount = 128;
				}
				else
				{
					p->Repeat = !(line & 0x80);
					p->LineCount = line & 0x7f;
				}

				// Disable H-DMA'ing into V-RAM (register 2118) for Hook
				/* XXX: instead of p->BAddress == 0x18, make S9xSetPPU fail
				 * XXX: writes to $2118/9 when appropriate
				 */
#ifdef SETA010_HDMA_FROM_CART
				if (!p->LineCount)
#else
				if (!p->LineCount || p->BAddress == 0x18)
#endif
				{
					byte &= ~mask;
					p->IndirectAddress += HDMAMemPointers [d] - HDMABasePointers [d];
					Memory.FillRAM [0x4305 + (d << 4)] = (uint8) p->IndirectAddress;
					Memory.FillRAM [0x4306 + (d << 4)] = p->IndirectAddress >> 8;
					continue;
				}

				p->Address++;
				p->FirstLine = 1;
				if (p->HDMAIndirectAddressing)
				{
					p->IndirectBank = Memory.FillRAM [0x4307 + (d << 4)];
					//again, no cycle charges while InDMA is set!
					CPU.Cycles+=SLOW_ONE_CYCLE<<2;
					S9xUpdateAPUTimer();
					p->IndirectAddress = S9xGetWord ((p->ABank << 16) + p->Address);
					p->Address += 2;
				}
				else
				{
					p->IndirectBank = p->ABank;
					p->IndirectAddress = p->Address;
				}
				HDMABasePointers [d] = HDMAMemPointers [d] = 
					S9xGetMemPointer ((p->IndirectBank << 16) + p->IndirectAddress);
#ifdef SETA010_HDMA_FROM_CART
				HDMARawPointers [d] = (p->IndirectBank << 16) + p->IndirectAddress;
#endif
			}
			else
			{
				CPU.Cycles += SLOW_ONE_CYCLE;
				S9xUpdateAPUTimer();
			}

			if (!HDMAMemPointers [d])
			{
				if (!p->HDMAIndirectAddressing)
				{
					p->IndirectBank = p->ABank;
					p->IndirectAddress = p->Address;
				}
#ifdef SETA010_HDMA_FROM_CART
				HDMARawPointers [d] = (p->IndirectBank << 16) + p->IndirectAddress;
#endif
				if (!(HDMABasePointers [d] = HDMAMemPointers [d] = 
					  S9xGetMemPointer ((p->IndirectBank << 16) + p->IndirectAddress)))
				{
					/* XXX: Instead of this, goto a slow path that first
					 * XXX: verifies src!=Address Bus B, then uses
					 * XXX: S9xGetByte(). Or make S9xGetByte return OpenBus
					 * XXX: (probably?) for Address Bus B while inDMA.
					 */
					byte &= ~mask;
					continue;
				}
				// Uncommenting the following line breaks Punchout - it starts
				// H-DMA during the frame.
				//p->FirstLine = TRUE;
			}
			if (p->Repeat && !p->FirstLine)
			{
				p->LineCount--;
				continue;
			}

			if (p->BAddress == 0x04){
				if(SNESGameFixes.Uniracers){
					PPU.OAMAddr = 0x10c;
					PPU.OAMFlip=0;
				}
			}

#ifdef DEBUGGER
			if (Settings.TraceSoundDSP && p->FirstLine && 
					p->BAddress >= 0x40 && p->BAddress <= 0x43)
				S9xTraceSoundDSP ("Spooling data!!!\n");
			if (Settings.TraceHDMA && p->FirstLine)
			{
				sprintf (String, "H-DMA[%d] (%d) 0x%02X%04X->0x21%02X %s, Count: %3d, Rep: %s, V-LINE: %3ld %02X%04X",
						p-DMA, p->TransferMode, p->IndirectBank,
						p->IndirectAddress,
						p->BAddress,
						p->HDMAIndirectAddressing ? "ind" : "abs",
						p->LineCount,
						p->Repeat ? "yes" : "no ", CPU.V_Counter,
						p->ABank, p->Address);
				S9xMessage (S9X_TRACE, S9X_HDMA_TRACE, String);
			}
#endif

			switch (p->TransferMode)
			{
				case 0:
					CPU.Cycles += SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]++), 0x2100 + p->BAddress);
					HDMAMemPointers [d]++;
#else
					S9xSetPPU (*HDMAMemPointers [d]++, 0x2100 + p->BAddress);
#endif
					break;
				case 5:
					CPU.Cycles += 2*SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 1), 0x2101 + p->BAddress);
					HDMARawPointers [d] += 2;
#else
					S9xSetPPU (*(HDMAMemPointers [d] + 0), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 1), 0x2101 + p->BAddress);
#endif
					HDMAMemPointers [d] += 2;
					/* fall through */
				case 1:
					CPU.Cycles += 2*SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 1), 0x2101 + p->BAddress);
					HDMARawPointers [d] += 2;
#else
					S9xSetPPU (*(HDMAMemPointers [d] + 0), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 1), 0x2101 + p->BAddress);
#endif
					HDMAMemPointers [d] += 2;
					break;
				case 2:
				case 6:
					CPU.Cycles += 2*SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 1), 0x2100 + p->BAddress);
					HDMARawPointers [d] += 2;
#else
					S9xSetPPU (*(HDMAMemPointers [d] + 0), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 1), 0x2100 + p->BAddress);
#endif
					HDMAMemPointers [d] += 2;
					break;
				case 3:
				case 7:
					CPU.Cycles += 4*SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 1), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 2), 0x2101 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 3), 0x2101 + p->BAddress);
					HDMARawPointers [d] += 4;
#else
					S9xSetPPU (*(HDMAMemPointers [d] + 0), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 1), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 2), 0x2101 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 3), 0x2101 + p->BAddress);
#endif
					HDMAMemPointers [d] += 4;
					break;
				case 4:
					CPU.Cycles += 4*SLOW_ONE_CYCLE;
					S9xUpdateAPUTimer();
#ifdef SETA010_HDMA_FROM_CART
					S9xSetPPU (S9xGetByte (HDMARawPointers [d]), 0x2100 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 1), 0x2101 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 2), 0x2102 + p->BAddress);
					S9xSetPPU (S9xGetByte (HDMARawPointers [d] + 3), 0x2103 + p->BAddress);
					HDMARawPointers [d] += 4;
#else
					S9xSetPPU (*(HDMAMemPointers [d] + 0), 0x2100 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 1), 0x2101 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 2), 0x2102 + p->BAddress);
					S9xSetPPU (*(HDMAMemPointers [d] + 3), 0x2103 + p->BAddress);
#endif
					HDMAMemPointers [d] += 4;
					break;
			}
			if (!p->HDMAIndirectAddressing)
				p->Address += HDMA_ModeByteCounts [p->TransferMode];
			p->IndirectAddress += HDMA_ModeByteCounts [p->TransferMode];
			/* XXX: Check for p->IndirectAddress crossing a mapping boundry,
			 * XXX: and invalidate HDMAMemPointers[d]
			 */
			p->FirstLine = FALSE;
			p->LineCount--;
		}
	}

	CPU.InDMA=FALSE;
    return (byte);
}

void S9xResetDMA ()
{
    int d;
    for (d = 0; d < 8; d++)
    {
		DMA [d].TransferDirection = FALSE;
		DMA [d].HDMAIndirectAddressing = FALSE;
		DMA [d].AAddressFixed = TRUE;
		DMA [d].AAddressDecrement = FALSE;
		DMA [d].TransferMode = 0xff;
		DMA [d].ABank = 0xff;
		DMA [d].AAddress = 0xffff;
		DMA [d].Address = 0xffff;
		DMA [d].BAddress = 0xff;
		DMA [d].TransferBytes = 0xffff;
    }
    for (int c = 0x4300; c < 0x4380; c += 0x10)
    {
		for (d = c; d < c + 12; d++)
			Memory.FillRAM [d] = 0xff;
		
		Memory.FillRAM [c + 0xf] = 0xff;
    }
}