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EightBitNet
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Merge branch 'master' of https://github.com/MoleskiCoder/EightBitNet

This commit is contained in:
Adrian Conlon 2019-11-30 14:06:48 +00:00
parent c15ec96862 15a8f312ff
commit e98f841e9f
1 changed files with 16 additions and 22 deletions
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38
LR35902/Bus.cs
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@ -38,6 +38,8 @@ namespace EightBit.GameBoy
private int romBank = 1;
private int ramBank = 0;
private int allowed = 0;
protected Bus()
{
this.IO = new IoRegisters(this);
@ -98,17 +100,17 @@ namespace EightBit.GameBoy
this.ValidateCartridgeType();
}
public int RunRasterLines()
public void RunRasterLines()
{
this.enabledLCD = (this.IO.Peek(IoRegisters.LCDC) & (byte)LcdcControl.LcdEnable) != 0;
this.IO.ResetLY();
return this.RunRasterLines(DisplayCharacteristics.RasterHeight);
this.RunRasterLines(DisplayCharacteristics.RasterHeight);
}
public int RunVerticalBlankLines()
public void RunVerticalBlankLines()
{
var lines = TotalLineCount - DisplayCharacteristics.RasterHeight;
return this.RunVerticalBlankLines(lines);
this.RunVerticalBlankLines(lines);
}
public override MemoryMapping Mapping(ushort address)
@ -322,21 +324,15 @@ namespace EightBit.GameBoy
}
}
private int RunRasterLines(int lines)
private void RunRasterLines(int lines)
{
var count = 0;
var allowed = CyclesPerLine;
for (var line = 0; line < lines; ++line)
{
var executed = this.RunRasterLine(allowed);
count += executed;
allowed = CyclesPerLine - (executed - CyclesPerLine);
this.RunRasterLine(CyclesPerLine);
}
return count;
}
private int RunVerticalBlankLines(int lines)
private void RunVerticalBlankLines(int lines)
{
/*
Vertical Blank interrupt is triggered when the LCD
@ -365,10 +361,10 @@ namespace EightBit.GameBoy
this.IO.TriggerInterrupt(Interrupts.VerticalBlank);
}
return this.RunRasterLines(lines);
this.RunRasterLines(lines);
}
private int RunRasterLine(int limit)
private void RunRasterLine(int suggested)
{
/*
A scanline normally takes 456 clocks (912 clocks in double speed
@ -393,7 +389,7 @@ namespace EightBit.GameBoy
The rest of the clocks of line 153 are spent in line 0 in mode 1!
*/
var count = 0;
this.allowed += suggested;
if (this.enabledLCD)
{
if (((this.IO.Peek(IoRegisters.STAT) & (byte)Bits.Bit6) != 0) && (this.IO.Peek(IoRegisters.LYC) == this.IO.Peek(IoRegisters.LY)))
@ -408,11 +404,11 @@ namespace EightBit.GameBoy
this.IO.TriggerInterrupt(Interrupts.DisplayControlStatus);
}
count += this.CPU.Run(80); // ~19us
this.allowed -= this.CPU.Run(80); // ~19us
// Mode 3, OAM/VRAM unavailable
this.IO.UpdateLcdStatusMode(LcdStatusMode.TransferringDataToLcd);
count += this.CPU.Run(170); // ~41us
this.allowed -= this.CPU.Run(170); // ~41us
// Mode 0
this.IO.UpdateLcdStatusMode(LcdStatusMode.HBlank);
@ -421,16 +417,14 @@ namespace EightBit.GameBoy
this.IO.TriggerInterrupt(Interrupts.DisplayControlStatus);
}
count += this.CPU.Run(limit - count); // ~48.6us
this.allowed -= this.CPU.Run(this.allowed); // ~48.6us
this.IO.IncrementLY();
}
else
{
count += this.CPU.Run(CyclesPerLine);
this.allowed -= this.CPU.Run(this.allowed);
}
return count;
}
}
}