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Start DMA

This commit is contained in:
ASNiVOR 2024-10-31 07:54:17 +00:00
parent 84e7fedcfe
commit 875a7d808c
2 changed files with 36 additions and 2 deletions
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32
src/BizHawk.Emulation.Cores/Consoles/Watara/SuperVision/ASIC.cs
View File

@ -55,6 +55,8 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
private int _intTimer;
private int _nmiTimer;
private bool _intFlag;
private bool _dmaInProgress;
private int _dmaCounter;
/// <summary>
/// ASIC is clocked at the same rate as the CPU
@ -62,6 +64,7 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
public void Clock()
{
CheckInterrupt();
CheckDMA();
VideoClock();
AudioClock();
@ -93,6 +96,33 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
}
}
/// <summary>
/// DMA Control
/// </summary>
private void CheckDMA()
{
if (_regs[R_DMA_CONTROL].Bit(7))
{
// DMA start requested
_dmaInProgress = true;
}
if (_dmaInProgress)
{
ushort source = (ushort) (_regs[R_DMA_SOURCE_HIGH] << 8 | _regs[R_DMA_SOURCE_LOW]);
ushort dest = (ushort) (_regs[R_DMA_DEST_HIGH] << 8 | _regs[R_DMA_DEST_LOW]);
_dmaCounter++;
if (_dmaCounter == 4096)
{
// wrap around
_dmaCounter = 0;
}
}
}
/// <summary>
/// CPU writes a byte of data to the port latched into the ASIC address pins
/// </summary>
@ -472,6 +502,8 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
ser.Sync(nameof(_intTimer), ref _intTimer);
ser.Sync(nameof(_nmiTimer), ref _nmiTimer);
ser.Sync(nameof(_intFlag), ref _intFlag);
ser.Sync(nameof(_dmaInProgress), ref _dmaInProgress);
ser.Sync(nameof(_dmaCounter), ref _dmaCounter);
ser.Sync(nameof(_field), ref _field);
ser.Sync(nameof(_latchedVRAM), ref _latchedVRAM);

6
src/BizHawk.Emulation.Cores/Consoles/Watara/SuperVision/LCD.cs
View File

@ -86,7 +86,8 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
{
// end of field
// write last pixel
WritePixels(data, framePolarity);
if (DisplayEnable)
WritePixels(data, framePolarity);
// setup for next frame
_vPos = 0;
@ -101,7 +102,8 @@ namespace BizHawk.Emulation.Cores.Consoles.SuperVision
}
else
{
WritePixels(data, framePolarity);
if (DisplayEnable)
WritePixels(data, framePolarity);
}
}