MMC5 Audio: Square channels + PCM (write mode only, no IRQs)

Core/APU.cpp

@@ -236,7 +236,7 @@ void APU::StreamState(bool saving)
 	Stream(_nesModel, squareChannel0, squareChannel1, triangleChannel, noiseChannel, deltaModulationChannel, frameCounter, mixer);
 }
 
-void APU::AddExpansionAudioDelta(AudioChannel channel, int8_t delta)
+void APU::AddExpansionAudioDelta(AudioChannel channel, int16_t delta)
 {
 	Instance->_mixer->SetExpansionAudioType(channel);
 	Instance->_mixer->AddExpansionAudioDelta(Instance->_currentCycle, delta);

Core/APU.h

@@ -63,5 +63,5 @@ class APU : public Snapshotable, public IMemoryHandler
 
 		static void StaticRun();
 
-		static void AddExpansionAudioDelta(AudioChannel channel, int8_t delta);
+		static void AddExpansionAudioDelta(AudioChannel channel, int16_t delta);
 };

Core/BaseApuChannel.h

@@ -41,7 +41,10 @@ public:
 		_period = 0;
 		_lastOutput = 0;
 		_previousCycle = 0;
-		_mixer->Reset();
+		if(_mixer) {
+			//_mixer is null/not needed for MMC5 square channels
+			_mixer->Reset();
+		}
 	}
 
 	virtual void StreamState(bool saving)
@@ -93,7 +96,7 @@ public:
 		return 0;
 	}
 
-	void AddOutput(int8_t output)
+	virtual void AddOutput(int8_t output)
 	{
 		if(output != _lastOutput) {
 			_mixer->AddDelta(_channel, _previousCycle, output - _lastOutput);

Core/Core.vcxproj

@@ -438,6 +438,7 @@
     <ClInclude Include="MMC3_49.h" />
     <ClInclude Include="MMC3_52.h" />
     <ClInclude Include="MMC3_ChrRam.h" />
+    <ClInclude Include="MMC5Audio.h" />
     <ClInclude Include="ModChannel.h" />
     <ClInclude Include="Namco163.h" />
     <ClInclude Include="Namco163Audio.h" />

Core/Core.vcxproj.filters

@@ -610,6 +610,9 @@
     <ClInclude Include="Sunsoft4.h">
       <Filter>Nes\Mappers\Sunsoft</Filter>
     </ClInclude>
+    <ClInclude Include="MMC5Audio.h">
+      <Filter>Nes\Mappers\MMC</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">

Core/MMC5.h

@@ -2,6 +2,7 @@
 #include "stdafx.h"
 #include "BaseMapper.h"
 #include "PPU.h"
+#include "MMC5Audio.h"
 
 class MMC5 : public BaseMapper
 {
@@ -10,6 +11,8 @@ private:
 	const uint8_t NtEmptyIndex = 5;
 	const uint8_t NtFillModeIndex = 6;
 
+	MMC5Audio _audio;
+
 	uint8_t _prgRamProtect1;
 	uint8_t _prgRamProtect2;
 
@@ -166,6 +169,8 @@ private:
 		if(!PPU::GetControlFlags().BackgroundEnabled && !PPU::GetControlFlags().SpritesEnabled) {
 			_ppuInFrame = false;
 		}
+
+		_audio.ProcessCpuClock();
 	}
 
 	virtual void NotifyVRAMAddressChange(uint16_t addr)
@@ -321,11 +326,12 @@ protected:
 
 		ArrayInfo<uint8_t> prgBanks = { _prgBanks, 5 };
 		ArrayInfo<uint16_t> chrBanks = { _chrBanks, 12 };
+		SnapshotInfo audio{ &_audio };
 		Stream(_prgRamProtect1, _prgRamProtect2, _fillModeTile, _fillModeColor, _verticalSplitEnabled, _verticalSplitRightSide,
 				_verticalSplitDelimiterTile, _verticalSplitScroll, _verticalSplitBank, _multiplierValue1, _multiplierValue2,
 				_nametableMapping, _extendedRamMode, _exAttributeLastNametableFetch, _exAttrLastFetchCounter, _exAttrSelectedChrBank, 
 				_prgMode, prgBanks, _chrMode, _chrUpperBits, chrBanks, _lastChrReg, 
-				_spriteFetch, _largeSprites, _irqCounterTarget, _irqEnabled, _previousScanline, _irqCounter, _irqPending, _ppuInFrame);
+				_spriteFetch, _largeSprites, _irqCounterTarget, _irqEnabled, _previousScanline, _irqCounter, _irqPending, _ppuInFrame, audio);
 
 		if(!saving) {
 			UpdatePrgBanks();
@@ -393,6 +399,10 @@ protected:
 			SwitchChrBank(addr, value);
 		} else {
 			switch(addr) {
+				case 0x5000: case 0x5001: case 0x5002: case 0x5003: case 0x5004: case 0x5005: case 0x5006: case 0x5007: case 0x5010: case 0x5011: case 0x5015:
+					_audio.WriteRegister(addr, value);
+					break;
+
 				case 0x5100: _prgMode = value & 0x03; UpdatePrgBanks(); break;
 				case 0x5101: _chrMode = value & 0x03; UpdateChrBanks(); break;
 				case 0x5102: _prgRamProtect1 = value & 0x03; UpdatePrgBanks(); break;
@@ -430,6 +440,9 @@ protected:
 	uint8_t ReadRegister(uint16_t addr)
 	{
 		switch(addr) {
+			case 0x5010: case 0x5015: 
+				return _audio.ReadRegister(addr);
+
 			case 0x5204:
 			{
 				uint8_t value = (_ppuInFrame ? 0x40 : 0x00) | (_irqPending ? 0x80 : 0x00);
@@ -441,6 +454,8 @@ protected:
 			case 0x5205: return (_multiplierValue1*_multiplierValue2) & 0xFF;
 			case 0x5206: return (_multiplierValue1*_multiplierValue2) >> 8;
 		}
-		return 0;
+
+		//Open bus
+		return (addr >> 8);
 	}
 };

Core/MMC5Audio.h

@@ -0,0 +1,150 @@
+#pragma once
+#include "stdafx.h"
+#include "SquareChannel.h"
+
+class MMC5Square : public SquareChannel
+{
+	int8_t _currentOutput;
+
+private:
+	virtual void InitializeSweep()
+	{
+		//"$5001 has no effect. The MMC5 pulse channels will not sweep, as they have no sweep unit."
+	}
+
+	bool IsMuted()
+	{
+		//"Frequency values less than 8 do not silence the MMC5 pulse channels; they can output ultrasonic frequencies."
+		return false;
+	}
+public:
+	MMC5Square() : SquareChannel(AudioChannel::MMC5, nullptr, false)
+	{
+		_currentOutput = 0;
+	}
+	
+	virtual void AddOutput(int8_t output)
+	{
+		_currentOutput = output;
+	}
+
+	int8_t GetOutput()
+	{
+		return _currentOutput;
+	}
+
+	void Run()
+	{
+		SquareChannel::Run(1);
+		EndFrame();
+	}
+};
+
+class MMC5Audio : public Snapshotable
+{
+private:
+	MMC5Square _square1;
+	MMC5Square _square2;
+	int16_t _audioCounter;
+	int16_t _lastOutput;
+
+	bool _pcmReadMode;
+	bool _pcmIrqEnabled;
+	uint8_t _pcmOutput;
+
+protected:
+	void StreamState(bool saving)
+	{
+		SnapshotInfo square1{ &_square1 };
+		SnapshotInfo square2{ &_square2 };
+		Stream(square1, square2, _audioCounter, _lastOutput, _pcmReadMode, _pcmIrqEnabled, _pcmOutput);
+	}
+
+public:
+	MMC5Audio()
+	{
+		_audioCounter = 0;
+		_lastOutput = 0;
+		_pcmReadMode = false;
+		_pcmIrqEnabled = false;
+		_pcmOutput = 0;
+	}
+
+	void ProcessCpuClock()
+	{
+		_audioCounter--;
+		_square1.Run();
+		_square2.Run();
+		if(_audioCounter <= 0) {
+			//~240hz envelope/length counter
+			switch(EmulationSettings::GetNesModel()) {
+				default:
+				case NesModel::NTSC: _audioCounter = CPU::ClockRateNtsc / 240; break;
+				case NesModel::PAL: _audioCounter = CPU::ClockRatePal / 240; break;
+				case NesModel::Dendy: _audioCounter = CPU::ClockRateDendy / 240; break;
+			}
+
+			_square1.TickLengthCounter();
+			_square1.TickEnvelope();
+			_square2.TickLengthCounter();
+			_square2.TickEnvelope();
+		}
+
+		int16_t summedOutput = (_square1.GetOutput() + _square2.GetOutput()) * 4 + _pcmOutput;
+		APU::AddExpansionAudioDelta(AudioChannel::MMC5, summedOutput - _lastOutput);
+		_lastOutput = summedOutput;
+
+		_square1.ReloadCounter();
+		_square2.ReloadCounter();
+	}
+
+	uint8_t ReadRegister(uint16_t addr)
+	{
+		switch(addr) {
+			case 0x5010:
+				//TODO: PCM IRQ
+				return 0;
+
+			case 0x5015:
+				uint8_t status = 0;
+				status |= _square1.GetStatus() ? 0x01 : 0x00;
+				status |= _square2.GetStatus() ? 0x02 : 0x00;
+				return status;
+		}
+
+		//Open bus
+		return (addr >> 8);
+	}
+
+	void WriteRegister(uint16_t addr, uint8_t value)
+	{
+		switch(addr) {
+			case 0x5000: case 0x5001: case 0x5002: case 0x5003:
+				_square1.WriteRAM(addr, value);
+				break;
+
+			case 0x5004: case 0x5005: case 0x5006: case 0x5007:
+				_square2.WriteRAM(addr, value);
+				break;
+
+			case 0x5010:
+				//TODO: Read mode & PCM IRQs are not implemented
+				_pcmReadMode = (value & 0x01) == 0x01;
+				_pcmIrqEnabled = (value & 0x80) == 0x80;
+				break;
+
+			case 0x5011:
+				if(!_pcmReadMode) {
+					if(value != 0) {
+						_pcmOutput = value;
+					}
+				}
+				break;
+
+			case 0x5015:
+				_square1.SetEnabled((value & 0x01) == 0x01);
+				_square2.SetEnabled((value & 0x02) == 0x02);
+				break;
+		}
+	}
+};

Core/SoundMixer.cpp

@@ -33,7 +33,7 @@ void SoundMixer::StreamState(bool saving)
 		UpdateRates();
 	}
 
-	ArrayInfo<int8_t> currentOutput = { _currentOutput, MaxChannelCount };
+	ArrayInfo<int16_t> currentOutput = { _currentOutput, MaxChannelCount };
 	Stream(_previousOutput, currentOutput);
 }
 
@@ -151,14 +151,15 @@ int16_t SoundMixer::GetOutputVolume()
 	int16_t expansionOutput = 0;
 	switch(_expansionAudioType) {
 		case AudioChannel::FDS: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 20); break;
-		case AudioChannel::VRC6: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 75); break;
+		case AudioChannel::MMC5: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 40); break;
 		case AudioChannel::Namco163: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 20); break;
 		case AudioChannel::Sunsoft5B: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 20); break;
+		case AudioChannel::VRC6: expansionOutput = (int16_t)(_currentOutput[ExpansionAudioIndex] * _volumes[ExpansionAudioIndex] * 75); break;
 	}
 	return squareVolume + tndVolume + expansionOutput;
 }
 
-void SoundMixer::AddDelta(AudioChannel channel, uint32_t time, int8_t delta)
+void SoundMixer::AddDelta(AudioChannel channel, uint32_t time, int16_t delta)
 {
 	if(delta != 0) {
 		_timestamps.push_back(time);
@@ -166,7 +167,7 @@ void SoundMixer::AddDelta(AudioChannel channel, uint32_t time, int8_t delta)
 	}
 }
 
-void SoundMixer::AddExpansionAudioDelta(uint32_t time, int8_t delta)
+void SoundMixer::AddExpansionAudioDelta(uint32_t time, int16_t delta)
 {
 	if(delta != 0) {
 		_timestamps.push_back(time);

Core/SoundMixer.h

@@ -36,8 +36,8 @@ private:
 	int16_t _previousOutput = 0;
 
 	vector<uint32_t> _timestamps;
-	int8_t _channelOutput[MaxChannelCount][CycleLength];
-	int8_t _currentOutput[MaxChannelCount];
+	int16_t _channelOutput[MaxChannelCount][CycleLength];
+	int16_t _currentOutput[MaxChannelCount];
 
 	blip_t* _blipBuf;
 	int16_t *_outputBuffer;
@@ -63,10 +63,10 @@ public:
 	void Reset();
 	
 	void PlayAudioBuffer(uint32_t cycle);
-	void AddDelta(AudioChannel channel, uint32_t time, int8_t delta);
+	void AddDelta(AudioChannel channel, uint32_t time, int16_t delta);
 
 	void SetExpansionAudioType(AudioChannel channel);
-	void AddExpansionAudioDelta(uint32_t time, int8_t delta);
+	void AddExpansionAudioDelta(uint32_t time, int16_t delta);
 	
 	static void StartRecording(string filepath);
 	static void StopRecording();

Core/SquareChannel.h

@@ -28,13 +28,13 @@ private:
 	uint32_t _sweepTargetPeriod = 0;
 	uint16_t _realPeriod = 0;
 	
-	bool IsMuted()
+	virtual bool IsMuted()
 	{
 		//A period of t < 8, either set explicitly or via a sweep period update, silences the corresponding pulse channel.
 		return _realPeriod < 8 || (!_sweepNegate && _sweepTargetPeriod > 0x7FF);
 	}
 
-	void InitializeSweep(uint8_t regValue)
+	virtual void InitializeSweep(uint8_t regValue)
 	{
 		_sweepEnabled = (regValue & 0x80) == 0x80;
 		_sweepNegate = (regValue & 0x08) == 0x08;

GUI.NET/Forms/Config/frmAudioConfig.Designer.cs

@@ -254,7 +254,6 @@
 			// trkMmc5Vol
 			// 
 			this.trkMmc5Vol.Anchor = System.Windows.Forms.AnchorStyles.Top;
-			this.trkMmc5Vol.Enabled = false;
 			this.trkMmc5Vol.Location = new System.Drawing.Point(81, 160);
 			this.trkMmc5Vol.Margin = new System.Windows.Forms.Padding(0);
 			this.trkMmc5Vol.Maximum = 100;