57 lines
1.1 KiB
C#
57 lines
1.1 KiB
C#
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using System.IO;
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namespace MyNes.Core
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{
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internal abstract class FFE : Board
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{
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protected bool irqEnable;
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protected int irqCounter;
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internal override void WriteEX(ref ushort address, ref byte data)
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{
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switch (address)
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{
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case 17665:
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irqEnable = false;
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NesEmu.IRQFlags &= -9;
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break;
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case 17666:
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irqCounter = (irqCounter & 0xFF00) | data;
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break;
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case 17667:
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irqEnable = true;
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irqCounter = (irqCounter & 0xFF) | (data << 8);
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break;
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}
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}
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internal override void OnCPUClock()
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{
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if (irqEnable)
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{
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irqCounter++;
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if (irqCounter >= 65535)
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{
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irqCounter = 0;
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NesEmu.IRQFlags |= 8;
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}
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}
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}
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internal override void WriteStateData(ref BinaryWriter bin)
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{
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base.WriteStateData(ref bin);
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bin.Write(irqEnable);
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bin.Write(irqCounter);
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}
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internal override void ReadStateData(ref BinaryReader bin)
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{
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base.ReadStateData(ref bin);
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irqEnable = bin.ReadBoolean();
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irqCounter = bin.ReadInt32();
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}
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}
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}
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