Mesen2/Core/NES/Mappers/Mmc3Variants/MMC3_187.h
2022-09-08 21:29:52 -04:00

95 lines
No EOL
2.3 KiB
C++

#pragma once
#include "pch.h"
#include "NES/Mappers/Nintendo/MMC3.h"
class MMC3_187: public MMC3
{
private:
uint8_t _exRegs[2] = {};
protected:
bool AllowRegisterRead() override { return true; }
void InitMapper() override
{
MMC3::InitMapper();
memset(_exRegs, 0, sizeof(_exRegs));
AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Any);
AddRegisterRange(0x6000, 0x6FFF, MemoryOperation::Write);
RemoveRegisterRange(0x8000, 0xFFFF, MemoryOperation::Read);
}
void SelectChrPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType = ChrMemoryType::Default) override
{
if((_chrMode && slot >= 4) || (!_chrMode && slot < 4)) {
page |= 0x100;
}
BaseMapper::SelectChrPage(slot, page);
}
void SelectPrgPage(uint16_t slot, uint16_t page, PrgMemoryType memoryType = PrgMemoryType::PrgRom) override
{
if(!(_exRegs[0] & 0x80)) {
BaseMapper::SelectPrgPage(slot, page & 0x3F, memoryType);
} else {
uint16_t exPage = _exRegs[0] & 0x1F;
if(_exRegs[0] & 0x20) {
if(_exRegs[0] & 0x40) {
exPage &= 0xFC;
BaseMapper::SelectPrgPage(0, exPage);
BaseMapper::SelectPrgPage(1, exPage +1);
BaseMapper::SelectPrgPage(2, exPage +2);
BaseMapper::SelectPrgPage(3, exPage +3);
} else {
exPage &= 0xFE;
BaseMapper::SelectPrgPage(0, (exPage << 1));
BaseMapper::SelectPrgPage(1, (exPage << 1) + 1);
BaseMapper::SelectPrgPage(2, (exPage << 1) + 2);
BaseMapper::SelectPrgPage(3, (exPage << 1) + 3);
}
} else {
BaseMapper::SelectPrgPage(0, (exPage << 1));
BaseMapper::SelectPrgPage(1, (exPage << 1) + 1);
BaseMapper::SelectPrgPage(2, (exPage << 1));
BaseMapper::SelectPrgPage(3, (exPage << 1) + 1);
}
}
}
uint8_t ReadRegister(uint16_t addr) override
{
uint8_t security[4] = { 0x83,0x83,0x42,0x00 };
return security[_exRegs[1] & 0x03];
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr < 0x8000) {
if(addr == 0x5000 || addr == 0x6000) {
_exRegs[0] = value;
MMC3::UpdatePrgMapping();
}
} else {
if(addr == 0x8000) {
_exRegs[1] = 1;
MMC3::WriteRegister(addr, value);
} else if(addr == 0x8001) {
if(_exRegs[1] == 1) {
MMC3::WriteRegister(addr, value);
}
} else {
MMC3::WriteRegister(addr, value);
}
}
}
void Serialize(Serializer& s) override
{
MMC3::Serialize(s);
SV(_exRegs[0]);
SV(_exRegs[1]);
}
};