bsnes/higan/gb/cartridge/huc1/huc1.cpp

51 lines
1.2 KiB
C++

auto Cartridge::HuC1::mmio_read(uint16 addr) -> uint8 {
if((addr & 0xc000) == 0x0000) { //$0000-3fff
return cartridge.rom_read(addr);
}
if((addr & 0xc000) == 0x4000) { //$4000-7fff
return cartridge.rom_read((rom_select << 14) | (addr & 0x3fff));
}
if((addr & 0xe000) == 0xa000) { //$a000-bfff
return cartridge.ram_read((ram_select << 13) | (addr & 0x1fff));
}
return 0x00;
}
auto Cartridge::HuC1::mmio_write(uint16 addr, uint8 data) -> void {
if((addr & 0xe000) == 0x0000) { //$0000-1fff
ram_writable = (data & 0x0f) == 0x0a;
return;
}
if((addr & 0xe000) == 0x2000) { //$2000-3fff
rom_select = data;
if(rom_select == 0) rom_select = 1;
return;
}
if((addr & 0xe000) == 0x4000) { //$4000-5fff
ram_select = data;
return;
}
if((addr & 0xe000) == 0x6000) { //$6000-7fff
model = data & 0x01;
return;
}
if((addr & 0xe000) == 0xa000) { //$a000-bfff
if(ram_writable == false) return;
return cartridge.ram_write((ram_select << 13) | (addr & 0x1fff), data);
}
}
auto Cartridge::HuC1::power() -> void {
ram_writable = false;
rom_select = 0x01;
ram_select = 0x00;
model = 0;
}