AxibugEmuOnline/AxibugEmuOnline.Client/Assets/VirtualNes.Core/Mapper/Mapper254.cs

307 lines
9.0 KiB
C#

using static VirtualNes.MMU;
using static VirtualNes.Core.CPU;
using INT = System.Int32;
using BYTE = System.Byte;
namespace VirtualNes.Core
{
public class Mapper254 : Mapper
{
BYTE[] reg = new BYTE[8];
BYTE prg0, prg1;
BYTE chr01, chr23, chr4, chr5, chr6, chr7;
BYTE irq_type;
BYTE irq_enable;
BYTE irq_counter;
BYTE irq_latch;
BYTE irq_request;
BYTE protectflag;
public Mapper254(NES parent) : base(parent)
{
}
public override void Reset()
{
for (int i = 0; i < 8; i++)
{
reg[i] = 0x00;
}
protectflag = 0;
prg0 = 0;
prg1 = 1;
SetBank_CPU();
chr01 = 0;
chr23 = 2;
chr4 = 4;
chr5 = 5;
chr6 = 6;
chr7 = 7;
SetBank_PPU();
irq_enable = 0; // Disable
irq_counter = 0;
irq_latch = 0;
irq_request = 0;
}
public override void WriteLow(ushort addr, byte data)
{
switch (addr & 0xF000)
{
case 0x6000:
case 0x7000:
MMU.CPU_MEM_BANK[addr >> 13][addr & 0x1FFF] = data;
break;
}
}
public override byte ReadLow(ushort addr)
{
if (addr >= 0x6000)
{
if (protectflag != 0)
{
return (MMU.CPU_MEM_BANK[addr >> 13][addr & 0x1FFF]);
}
else
{
return (byte)((MMU.CPU_MEM_BANK[addr >> 13][addr & 0x1FFF]) ^ 0x1);
}
}
return base.ReadLow(addr);
}
public override void Write(ushort addr, byte data)
{
switch (addr & 0xE001)
{
case 0x8000:
protectflag = 0xFF;
reg[0] = data;
SetBank_CPU();
SetBank_PPU();
break;
case 0x8001:
reg[1] = data;
switch (reg[0] & 0x07)
{
case 0x00:
chr01 = (byte)(data & 0xFE);
SetBank_PPU();
break;
case 0x01:
chr23 = (byte)(data & 0xFE);
SetBank_PPU();
break;
case 0x02:
chr4 = data;
SetBank_PPU();
break;
case 0x03:
chr5 = data;
SetBank_PPU();
break;
case 0x04:
chr6 = data;
SetBank_PPU();
break;
case 0x05:
chr7 = data;
SetBank_PPU();
break;
case 0x06:
prg0 = data;
SetBank_CPU();
break;
case 0x07:
prg1 = data;
SetBank_CPU();
break;
}
break;
case 0xA000:
reg[2] = data;
if (!nes.rom.Is4SCREEN())
{
if ((data & 0x01) != 0) MMU.SetVRAM_Mirror(MMU.VRAM_HMIRROR);
else MMU.SetVRAM_Mirror(MMU.VRAM_VMIRROR);
}
break;
case 0xA001:
reg[3] = data;
break;
case 0xC000:
reg[4] = data;
irq_counter = data;
irq_request = 0;
nes.cpu.ClrIRQ(CPU.IRQ_MAPPER);
break;
case 0xC001:
reg[5] = data;
irq_latch = data;
irq_request = 0;
nes.cpu.ClrIRQ(CPU.IRQ_MAPPER);
break;
case 0xE000:
reg[6] = data;
irq_enable = 0;
irq_request = 0;
nes.cpu.ClrIRQ(CPU.IRQ_MAPPER);
break;
case 0xE001:
reg[7] = data;
irq_enable = 1;
irq_request = 0;
nes.cpu.ClrIRQ(CPU.IRQ_MAPPER);
break;
}
}
public override void Clock(int cycles)
{
// if( irq_request && (nes->GetIrqType() == NES::IRQ_CLOCK) ) {
// nes->cpu->IRQ_NotPending();
// }
}
public override void HSync(int scanline)
{
if ((scanline >= 0 && scanline <= 239))
{
if (nes.ppu.IsDispON())
{
if (irq_enable != 0 && irq_request == 0)
{
if (scanline == 0)
{
if (irq_counter != 0)
{
irq_counter--;
}
}
if ((irq_counter--) == 0)
{
irq_request = 0xFF;
irq_counter = irq_latch;
nes.cpu.SetIRQ(CPU.IRQ_MAPPER);
}
}
}
}
// if( irq_request && (nes->GetIrqType() == NES::IRQ_HSYNC) ) {
// nes->cpu->IRQ_NotPending();
// }
}
public void SetBank_CPU()
{
if ((reg[0] & 0x40)!=0)
{
SetPROM_32K_Bank(PROM_8K_SIZE - 2, prg1, prg0, PROM_8K_SIZE - 1);
}
else
{
SetPROM_32K_Bank(prg0, prg1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
}
}
public void SetBank_PPU()
{
if (VROM_1K_SIZE != 0)
{
if ((reg[0] & 0x80)!= 0)
{
SetVROM_8K_Bank(chr4, chr5, chr6, chr7,
chr01, chr01 + 1, chr23, chr23 + 1);
}
else
{
SetVROM_8K_Bank(chr01, chr01 + 1, chr23, chr23 + 1,
chr4, chr5, chr6, chr7);
}
}
else
{
if ((reg[0] & 0x80) != 0)
{
SetCRAM_1K_Bank(4, (chr01 + 0) & 0x07);
SetCRAM_1K_Bank(5, (chr01 + 1) & 0x07);
SetCRAM_1K_Bank(6, (chr23 + 0) & 0x07);
SetCRAM_1K_Bank(7, (chr23 + 1) & 0x07);
SetCRAM_1K_Bank(0, chr4 & 0x07);
SetCRAM_1K_Bank(1, chr5 & 0x07);
SetCRAM_1K_Bank(2, chr6 & 0x07);
SetCRAM_1K_Bank(3, chr7 & 0x07);
}
else
{
SetCRAM_1K_Bank(0, (chr01 + 0) & 0x07);
SetCRAM_1K_Bank(1, (chr01 + 1) & 0x07);
SetCRAM_1K_Bank(2, (chr23 + 0) & 0x07);
SetCRAM_1K_Bank(3, (chr23 + 1) & 0x07);
SetCRAM_1K_Bank(4, chr4 & 0x07);
SetCRAM_1K_Bank(5, chr5 & 0x07);
SetCRAM_1K_Bank(6, chr6 & 0x07);
SetCRAM_1K_Bank(7, chr7 & 0x07);
}
}
}
public override bool IsStateSave()
{
return true;
}
public override void SaveState(byte[] p)
{
for (int i = 0; i < 8; i++)
{
p[i] = reg[i];
}
p[8] = prg0;
p[9] = prg1;
p[10] = chr01;
p[11] = chr23;
p[12] = chr4;
p[13] = chr5;
p[14] = chr6;
p[15] = chr7;
p[16] = irq_enable;
p[17] = irq_counter;
p[18] = irq_latch;
p[19] = irq_request;
p[20] = protectflag;
}
public override void LoadState(byte[] p)
{
for (int i = 0; i < 8; i++)
{
reg[i] = p[i];
}
prg0 = p[8];
prg1 = p[9];
chr01 = p[10];
chr23 = p[11];
chr4 = p[12];
chr5 = p[13];
chr6 = p[14];
chr7 = p[15];
irq_enable = p[16];
irq_counter = p[17];
irq_latch = p[18];
irq_request = p[19];
protectflag = p[20];
}
}
}