AxibugEmuOnline/Core/VirtualNes.Core/Mapper/Mapper017.cs

133 lines
3.6 KiB
C#
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using System;
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;
namespace VirtualNes.Core
{
public class Mapper017 : Mapper
{
BYTE irq_enable;
INT irq_counter;
INT irq_latch;
public Mapper017(NES parent) : base(parent)
{
}
public override void Reset()
{
SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
if (VROM_1K_SIZE != 0)
{
SetVROM_8K_Bank(0);
}
irq_enable = 0;
irq_counter = 0;
irq_latch = 0;
}
//void Mapper017::WriteLow(WORD addr, BYTE data)
public override void WriteLow(ushort addr, byte data)
{
switch (addr)
{
case 0x42FE:
if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_MIRROR4H);
else SetVRAM_Mirror(VRAM_MIRROR4L);
break;
case 0x42FF:
if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
else SetVRAM_Mirror(VRAM_VMIRROR);
break;
case 0x4501:
irq_enable = 0;
nes.cpu.ClrIRQ(IRQ_MAPPER);
break;
case 0x4502:
irq_latch = (irq_latch & 0xFF00) | data;
break;
case 0x4503:
irq_latch = (irq_latch & 0x00FF) | ((INT)data << 8);
irq_counter = irq_latch;
irq_enable = 0xFF;
break;
case 0x4504:
case 0x4505:
case 0x4506:
case 0x4507:
SetPROM_8K_Bank((byte)(addr & 0x07), data);
break;
case 0x4510:
case 0x4511:
case 0x4512:
case 0x4513:
case 0x4514:
case 0x4515:
case 0x4516:
case 0x4517:
SetVROM_1K_Bank((byte)(addr & 0x07), data);
break;
default:
base.WriteLow(addr, data);
break;
}
}
//void Mapper017::HSync(INT scanline)
public override void HSync(int scanline)
{
if (irq_enable != 0)
{
if (irq_counter >= 0xFFFF - 113)
{
nes.cpu.SetIRQ(IRQ_MAPPER);
// nes.cpu.IRQ();
// irq_counter = 0;
// irq_enable = 0;
irq_counter &= 0xFFFF;
}
else
{
irq_counter += 113;
}
}
}
//void Mapper017::SaveState(LPBYTE p)
public override void SaveState(byte[] p)
{
p[0] = irq_enable;
//*(INT*)&p[1] = irq_counter;
BitConverter.GetBytes(irq_counter).CopyTo(p, 1);
//*(INT*)&p[5] = irq_latch;
BitConverter.GetBytes(irq_latch).CopyTo(p, 5);
}
//void Mapper017::LoadState(LPBYTE p)
public override void LoadState(byte[] p)
{
irq_enable = p[0];
//irq_counter = *(INT*)&p[1];
irq_counter = BitConverter.ToInt32(p, 1);
//irq_latch = *(INT*)&p[5];
irq_latch = BitConverter.ToInt32(p, 5);
}
public override bool IsStateSave()
{
return true;
}
}
}