bsnes/gb/cartridge/mbc2/mbc2.cpp

43 lines
976 B
C++

#ifdef CARTRIDGE_CPP
uint8 Cartridge::MBC2::mmio_read(uint16 addr) {
if((addr & 0xc000) == 0x0000) { //$0000-3fff
return cartridge.rom_read(addr);
}
if((addr & 0xc000) == 0x4000) { //$4000-7fff
return cartridge.rom_read((rom_select << 14) | (addr & 0x3fff));
}
if((addr & 0xee00) == 0xa000) { //$a000-a1ff
if(ram_enable) return cartridge.ram_read(addr & 0x1ff);
return 0x00;
}
return 0x00;
}
void Cartridge::MBC2::mmio_write(uint16 addr, uint8 data) {
if((addr & 0xe000) == 0x0000) { //$0000-1fff
if(!(addr & 0x0100)) ram_enable = (data & 0x0f) == 0x0a;
return;
}
if((addr & 0xe000) == 0x2000) { //$2000-3fff
if( (addr & 0x0100)) rom_select = (data & 0x0f) + ((data & 0x0f) == 0);
return;
}
if((addr & 0xee00) == 0xa000) { //$a000-a1ff
if(ram_enable) cartridge.ram_write(addr & 0x1ff, data & 0x0f);
return;
}
}
void Cartridge::MBC2::power() {
ram_enable = false;
rom_select = 0x01;
}
#endif