bsnes/higan/gb/cartridge/mbc7/mbc7.cpp

87 lines
2.1 KiB
C++

auto Cartridge::MBC7::read(uint16 address) -> uint8 {
if((address & 0xc000) == 0x0000) { //$0000-3fff
return cartridge.rom.read(address.bits(0,13));
}
if((address & 0xc000) == 0x4000) { //$4000-7fff
return cartridge.rom.read(io.rom.bank << 14 | address.bits(0,13));
}
if((address & 0xf000) == 0xa000) { //$a000-afff
if(!io.ram.enable[0] || !io.ram.enable[1]) return 0xff;
switch(address.bits(4,7)) {
case 2: return io.accelerometer.x.bits(0, 7);
case 3: return io.accelerometer.x.bits(8,15);
case 4: return io.accelerometer.y.bits(0, 7);
case 5: return io.accelerometer.y.bits(8,15);
case 6: return 0x00; //z?
case 7: return 0xff; //z?
case 8: return 0xff;
}
return 0xff;
}
return 0xff;
}
auto Cartridge::MBC7::write(uint16 address, uint8 data) -> void {
if((address & 0xe000) == 0x0000) { //$0000-1fff
io.ram.enable[0] = data.bits(0,3) == 0xa;
if(!io.ram.enable[0]) io.ram.enable[1] = false;
return;
}
if((address & 0xe000) == 0x2000) { //$2000-3fff
io.rom.bank = data;
if(!io.rom.bank) io.rom.bank = 1;
return;
}
if((address & 0xe000) == 0x4000) { //$4000-5fff
if(!io.ram.enable[0]) return;
io.ram.enable[1] = data == 0x40;
}
if((address & 0xf000) == 0xa000) { //$a000-afff
if(!io.ram.enable[0] || !io.ram.enable[1]) return;
switch(address.bits(4,7)) {
case 0: {
if(data != 0x55) break;
io.accelerometer.x = 0x8000;
io.accelerometer.y = 0x8000;
break;
}
case 1: {
if(data != 0xaa) break;
io.accelerometer.x = 0x8000 + platform->inputPoll(ID::Port::Hardware, ID::Device::Controls, 8);
io.accelerometer.y = 0x8000 + platform->inputPoll(ID::Port::Hardware, ID::Device::Controls, 9);
break;
}
case 8: {
break;
}
}
return;
}
}
auto Cartridge::MBC7::power() -> void {
io = {};
}
auto Cartridge::MBC7::serialize(serializer& s) -> void {
s.integer(io.rom.bank);
s.integer(io.ram.enable[0]);
s.integer(io.ram.enable[1]);
s.integer(io.accelerometer.x);
s.integer(io.accelerometer.y);
}