bsnes/fc/cartridge/board/nes-axrom.cpp

50 lines
1.0 KiB
C++

//NES-AMROM
//NES-ANROM
//NES-AN1ROM
//NES-AOROM
struct NES_AxROM : Board {
NES_AxROM(Markup::Node& document) : Board(document) {
}
auto prg_read(uint addr) -> uint8 {
if(addr & 0x8000) return prgrom.read((prg_bank << 15) | (addr & 0x7fff));
return cpu.mdr();
}
auto prg_write(uint addr, uint8 data) -> void {
if(addr & 0x8000) {
prg_bank = data & 0x0f;
mirror_select = data & 0x10;
}
}
auto chr_read(uint addr) -> uint8 {
if(addr & 0x2000) return ppu.ciram_read((mirror_select << 10) | (addr & 0x03ff));
return Board::chr_read(addr);
}
auto chr_write(uint addr, uint8 data) -> void {
if(addr & 0x2000) return ppu.ciram_write((mirror_select << 10) | (addr & 0x03ff), data);
return Board::chr_write(addr, data);
}
auto power() -> void {
}
auto reset() -> void {
prg_bank = 0x0f;
mirror_select = 0;
}
auto serialize(serializer& s) -> void {
Board::serialize(s);
s.integer(prg_bank);
s.integer(mirror_select);
}
uint4 prg_bank;
bool mirror_select;
};