bsnes/higan/ws/cpu/memory.cpp

29 lines
785 B
C++

auto CPU::ramRead(uint16 addr) -> uint8 {
if(WS() && addr >= 0x4000) return 0x90;
return iram[addr];
}
auto CPU::ramWrite(uint16 addr, uint8 data) -> void {
if(WS() && addr >= 0x4000) return;
iram[addr] = data;
}
auto CPU::portRead(uint16 addr) -> uint8 {
//HW_FLAGS
if(addr == 0x00a0) {
return 1 << 7 //1 = built-in self-test passed
| 1 << 2 //0 = 8-bit bus width; 1 = 16-bit bus width
| !WS() << 1 //0 = WonderSwan; 1 = WonderSwan Color or SwanCrystal
| 1 << 0; //0 = BIOS mapped; 1 = cartridge mapped
}
return 0x00; //should never occur
}
auto CPU::portWrite(uint16 addr, uint8 data) -> void {
//HW_FLAGS
if(addr == 0x00a0) {
//todo: d2 (bus width) bit is writable; but ... it will do very bad things
}
}