[NES] general ppu timing, mmc3, and nt view fixups.

BizHawk.Emulation/Consoles/Nintendo/Docs/test_status.txt

@@ -3,13 +3,13 @@ look for tests here: http://wiki.nesdev.com/w/index.php/Emulator_tests
 ==blargg's tests==
 
 MMC3: 
-	FAIL for 4 and 6. i think 4 might not fail until some invisible PPU operations are correct. neither nintendulator or fceux pass these.
+	FAIL for 6. neither nintendulator or fceux pass this. we should be able to pass it once mmc3 variant support is finalized.
 
 ppu tests: 
 	PASS for all but power_up_palette.nes which is lame
 
 ppu_vbl_nmi:
-	FAIL for 9. But hardly anyone passes this.....
+	FAIL for 10. But hardly anyone passes this.....
 	
 sprite hit tests:
 	FAIL for 9 and 10. fceux passes 10 (oldppu) and nintendulator passes both. 
@@ -21,9 +21,6 @@ cpu_timing_test.nes
 official_only.nes
 	PASS
 	
-all_instrs.nes
-	FAIL (freezes emu??). I think this requires undocumented instructions.
-	
 instr_timing.nes
 	PASS	
 	
@@ -33,6 +30,9 @@ cpu_interrupts.nes
 instr_misc.nes
 	PASS
 	
+all_instrs.nes
+	FAIL (undocumented opcodes)
+	
 =============
 	
 nestest.nes

BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs

@@ -13,6 +13,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		{
 			void Create(NES nes);
 			bool Configure(NES.EDetectionOrigin origin);
+			
+			//gets called once per PPU clock, for boards with complex behaviour which must be monitoring clock (i.e. mmc3 irq counter)
+			void ClockPPU();
+
 			byte ReadPRG(int addr);
 			byte ReadPPU(int addr); byte PeekPPU(int addr);
 			void AddressPPU(int addr);
@@ -49,6 +53,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				this.NES = nes;
 			}
 			public abstract bool Configure(NES.EDetectionOrigin origin);
+			public virtual void ClockPPU() { }
 
 			public CartInfo Cart { get { return NES.cart; } }
 			public NES NES { get; set; }

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3_family.cs

@@ -109,7 +109,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		//state
 		public NES.NESBoardBase.EMirrorType mirror;
-		int ppubus_state, ppubus_statecounter;
+		int a12_old;
 		byte irq_reload, irq_counter;
 		bool irq_pending, irq_enable;
 
@@ -147,6 +147,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					SyncIRQ();
 					break;
 				case 0x6001: //$E001 - IRQ Enable
+					//board.NES.LogLine("irq en");
 					irq_enable = true;
 					SyncIRQ();
 					break;
@@ -156,7 +157,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		void IRQ_EQ_Pass()
 		{
 			if (irq_enable)
+			{
+				//board.NES.LogLine("mmc3 IRQ");
 				irq_pending = true;
+			}
 			SyncIRQ();
 		}
 
@@ -174,7 +178,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			else
 			{
 				irq_counter--;
-				//Console.WriteLine(irq_counter);
 				if (irq_counter == 0)
 				{
 					IRQ_EQ_Pass();
@@ -182,22 +185,50 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 		}
 
-		//TODO - this should be determined from NES timestamps to correctly emulate ppu writes interfering
+		//it really seems like these should be the same but i cant seem to unify them.
-		public void Tick_PPU(int addr)
+		//theres no sense in delaying the IRQ, so its logic must be tied to the separator.
+		//the hint, of course, is that the countdown value is the same.
+		//will someone else try to unify them?
+		int separator_counter;
+		int irq_countdown;
+
+		public void ClockPPU()
 		{
-			ppubus_statecounter++;
+			if (separator_counter > 0)
-			int state = (addr >> 12) & 1;
+				separator_counter--;
-			if (ppubus_state == 0 && ppubus_statecounter > 1 && state == 1)
+
+			if (irq_countdown > 0)
 			{
-				ppubus_statecounter = 0;
+				irq_countdown--;
+				if (irq_countdown == 0)
+				{
+					//board.NES.LogLine("ClockIRQ");
 					ClockIRQ();
 				}
-			if (ppubus_state != state)
-			{
-				ppubus_state = state;
 			}
 		}
 
+
+		public void AddressPPU(int addr)
+		{
+			int a12 = (addr >> 12) & 1;
+			bool rising_edge = (a12 == 1 && a12_old == 0);
+			if (rising_edge)
+			{
+				if (separator_counter > 0)
+				{
+					separator_counter = 15;
+				}
+				else
+				{
+					separator_counter = 15;
+					irq_countdown = 15;
+				}
+			}
+
+			a12_old = a12;
+		}
+
 	}
 
 	public abstract class MMC3_Family_Board_Base : NES.NESBoardBase
@@ -276,7 +307,12 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		public override void AddressPPU(int addr)
 		{
-			mmc3.Tick_PPU(addr);
+			mmc3.AddressPPU(addr);
+		}
+
+		public override void ClockPPU()
+		{
+			mmc3.ClockPPU();
 		}
 
 		protected override void BaseSetup()

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/TQROM.cs

@@ -33,7 +33,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				int use_ram = (bank_1k >> 6) & 1;
 				if (use_ram == 1)
 				{
-					mmc3.Tick_PPU(addr);
 					addr = ((bank_1k&0x3f) << 10) | (addr & 0x3FF);
 					addr &= 0x1FFF;
 					return VRAM[addr];
@@ -52,7 +51,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				int use_ram = (bank_1k >> 6) & 1;
 				if (use_ram == 1)
 				{
-					mmc3.Tick_PPU(addr);
 					addr = ((bank_1k & 0x3f) << 10) | (addr & 0x3FF);
 					addr &= 0x1FFF;
 					VRAM[addr] = value;

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/TVROM.cs

@@ -30,7 +30,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		public override byte ReadPPU(int addr)
 		{
-			mmc3.Tick_PPU(addr);
 			if (addr < 0x2000)
 			{
 				//read patterns from mapper controlled area
@@ -44,7 +43,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		public override void WritePPU(int addr, byte value)
 		{
-			mmc3.Tick_PPU(addr);
 			if (addr < 0x2000)
 			{
 				//nothing wired here

BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs

@@ -90,6 +90,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		protected void RunCpu(int ppu_cycles)
 		{
+			//not being used right now. maybe needed later.
+			//Timestamp += ppu_cycles;
+
 			int cycles = ppu_cycles;
 			if (ppu.PAL)
 			    cycles *= 15;
@@ -111,7 +114,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				cpu_accumulate -= 48*todo;
 				cpu.Execute(todo);
 				apu.Run(todo);
-				ppu.TickCpu();
+				ppu.PostCpuInstruction(todo);
 			}
 		}
 

BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs

@@ -231,6 +231,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
         bool lagged = true;
         bool islag = false;
 		public int Frame { get { return _frame; } set { _frame = value; } }
+		public long Timestamp { get; private set; }
         public int LagCount { get { return _lagcount; } set { _lagcount = value; } }
         public bool IsLagFrame { get { return islag; } }
 

BizHawk.Emulation/Consoles/Nintendo/NES/PPU.cs

@@ -23,8 +23,13 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 
 			//when the ppu issues a read it goes through here and into the game board
-			public byte ppubus_read(int addr)
+			public byte ppubus_read(int addr, bool ppu)
 			{
+				//speculative -- hardware doesnt touch the bus when the PPU is disabled
+				//(without this, smb3 title screen creates garbage when skipped)
+				if (!reg_2001.PPUON && ppu)
+					return 0xFF;
+
 				nes.board.AddressPPU(addr);
 				//apply freeze
 				if (ppubus_freeze[addr].IsFrozen)
@@ -91,12 +96,15 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				nes.cpu.NMI = true;
 			}
 
-			public void TickCpu()
+			//this gets called once after each cpu instruction executes.
+			//anything that needs to happen at instruction granularity can get checked here
+			//to save having to check it at ppu cycle granularity
+			public void PostCpuInstruction(int todo)
 			{
-				if (NMI_PendingCycles > 0)
+				if (NMI_PendingInstructions > 0)
 				{
-					NMI_PendingCycles--;
+					NMI_PendingInstructions--;
-					if (NMI_PendingCycles == 0)
+					if (NMI_PendingInstructions <= 0)
 					{
 						TriggerNMI();
 					}
@@ -105,17 +113,15 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 			void runppu(int x)
 			{
-				//pputime+=x;
-
-				//DON'T LIKE THIS....
 				ppur.status.cycle += x;
 				while(ppur.status.cycle >= ppur.status.end_cycle)
 					ppur.status.cycle -= ppur.status.end_cycle;
 
-				if(x == 0) return;
+				//run one ppu cycle at a time so we can interact with the ppu and clockPPU at high granularity
-
+				for (int i = 0; i < x; i++)
+				{
+					//might not actually run a cpu cycle if there are none to be run right now
 					nes.RunCpu(1);
-				x--;
 
 					if (Reg2002_vblank_active_pending)
 					{
@@ -130,9 +136,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 						Reg2002_vblank_clear_pending = false;
 					}
 
-				
+					nes.board.ClockPPU();
-				if (x == 0) return;
+				}
-				nes.RunCpu(x);
 			}
 
 			//hack

BizHawk.Emulation/Consoles/Nintendo/NES/PPU.regs.cs

@@ -296,7 +296,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			Bit Reg2002_vblank_active;  //Vertical blank start (0: has not started; 1: has started)
 			bool Reg2002_vblank_active_pending; //set of Reg2002_vblank_active is pending
 			bool Reg2002_vblank_clear_pending; //ppu's clear of vblank flag is pending
-			int NMI_PendingCycles;
+			int NMI_PendingInstructions;
 			byte PPUGenLatch;
 			public PPUREGS ppur;
 			public Reg_2000 reg_2000;
@@ -330,7 +330,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				if (!reg_2000.vblank_nmi_gen & ((value & 0x80) != 0) && (Reg2002_vblank_active) && !Reg2002_vblank_clear_pending)
 				{
 					//if we just unleashed the vblank interrupt then activate it now
-					NMI_PendingCycles = 2;
+					NMI_PendingInstructions = 2;
 				}
 				reg_2000.Value = value;
 			}
@@ -465,7 +465,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				byte ret = VRAMBuffer;
 
 				//in any case, we read from the ppu bus
-				VRAMBuffer = ppubus_read(addr);
+				VRAMBuffer = ppubus_read(addr,false);
 
 				//but reads from the palette are implemented in the PPU and return immediately
 				if ((addr & 0x3F00) == 0x3F00)

BizHawk.Emulation/Consoles/Nintendo/NES/PPU.run.cs

@@ -27,11 +27,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 			void Read_bgdata(ref BGDataRecord bgdata) {
 				int addr = ppur.get_ntread();
-				bgdata.nt = ppubus_read(addr);
+				bgdata.nt = ppubus_read(addr, true);
 				runppu(kFetchTime);
 
 				addr = ppur.get_atread();
-				byte at = ppubus_read(addr);
+				byte at = ppubus_read(addr, true);
 
 				//modify at to get appropriate palette shift
 				if((ppur.vt&2)!=0) at >>= 4;
@@ -53,10 +53,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				runppu(1);
 
 				addr = ppur.get_ptread(bgdata.nt);
-				bgdata.pt_0 = ppubus_read(addr);
+				bgdata.pt_0 = ppubus_read(addr, true);
 				runppu(kFetchTime);
 				addr |= 8;
-				bgdata.pt_1 = ppubus_read(addr);
+				bgdata.pt_1 = ppubus_read(addr, true);
 				runppu(kFetchTime);
 			}
 
@@ -380,11 +380,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 							//pattern table fetches
 							int addr = patternAddress;
-							oam->patterns[0] = ppubus_read(addr);
+							oam->patterns[0] = ppubus_read(addr, true);
 							if (realSprite) runppu(kFetchTime);
 
 							addr += 8;
-							oam->patterns[1] = ppubus_read(addr);
+							oam->patterns[1] = ppubus_read(addr, true);
 							if (realSprite) runppu(kFetchTime);
 
 							//hflip
@@ -405,7 +405,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					//screen (or basically, the first nametable address that will be accessed when
 					//the PPU is fetching background data on the next scanline).
 					//(not implemented yet)
-					runppu(kFetchTime * 2);
 					if (sl == 0)
 					{
 						if (idleSynch && reg_2001.show_bg && !PAL)
@@ -421,6 +420,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					for (int xt = 0; xt < 2; xt++)
 						Read_bgdata(ref bgdata[xt]);
 
+					runppu(kFetchTime * 2);
+
 					//After memory access 170, the PPU simply rests for 4 cycles (or the
 					//equivelant of half a memory access cycle) before repeating the whole
 					//pixel/scanline rendering process. If the scanline being rendered is the very

BizHawk.MultiClient/NEStools/NESNameTableViewer.cs

@@ -63,8 +63,8 @@ namespace BizHawk.MultiClient
 					int nt = ppu.ppubus_peek(ntbyte_ptr + 0x2000);
 					
 					int at = ppu.ppubus_peek(atbyte_ptr + 0x2000);
-					if((ty&1)!=0) at >>= 4;
+					if((ty&2)!=0) at >>= 4;
-					if((tx&1)!=0) at >>= 2;
+					if((tx&2)!=0) at >>= 2;
 					at &= 0x03;
 					at <<= 2;
 
@@ -74,6 +74,10 @@ namespace BizHawk.MultiClient
 					int pt_0 = ppu.ppubus_peek(pt_addr);
 					int pt_1 = ppu.ppubus_peek(pt_addr + 8);
 					int pixel = ((pt_0 >> (7 - bgpx)) & 1) | (((pt_1 >> (7 - bgpx)) & 1) << 1);
+					
+					//if the pixel is transparent, draw the backdrop color
+					//TODO - consider making this optional? nintendulator does it and fceux doesnt need to do it due to buggy palette logic which creates the same effect
+					if(pixel!=0)
 						pixel |= at;
 
 					pixel = ppu.PALRAM[pixel];

BizHawk.MultiClient/NEStools/NESPPU.cs

@@ -115,15 +115,6 @@ namespace BizHawk.MultiClient
             }
 			PatternView.pattern.UnlockBits(bmpdata);
 			PatternView.Refresh();
-
-            //Nametable viewer
-            for (int i = 0; i < 30; i++)
-            {
-                for (int j = 0; j < 32; j++)
-                {
-                    int v = Nes.ppu.ppubus_read(0x2000 + i + j);
-                }
-            }
 		}
 
         private void NESPPU_Load(object sender, EventArgs e)