mirror of https://github.com/bsnes-emu/bsnes.git
53 lines
1.2 KiB
C++
53 lines
1.2 KiB
C++
//NES-CNROM
|
|
|
|
struct NES_CNROM : Board {
|
|
NES_CNROM(Markup::Node& document) : Board(document) {
|
|
settings.mirror = document["board/mirror/mode"].text() == "vertical" ? 1 : 0;
|
|
}
|
|
|
|
auto prg_read(uint addr) -> uint8 {
|
|
if(addr & 0x8000) return prgrom.read(addr & 0x7fff);
|
|
return cpu.mdr();
|
|
}
|
|
|
|
auto prg_write(uint addr, uint8 data) -> void {
|
|
if(addr & 0x8000) chr_bank = data & 0x03;
|
|
}
|
|
|
|
auto chr_read(uint addr) -> uint8 {
|
|
if(addr & 0x2000) {
|
|
if(settings.mirror == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff);
|
|
return ppu.ciram_read(addr & 0x07ff);
|
|
}
|
|
addr = (chr_bank * 0x2000) + (addr & 0x1fff);
|
|
return Board::chr_read(addr);
|
|
}
|
|
|
|
auto chr_write(uint addr, uint8 data) -> void {
|
|
if(addr & 0x2000) {
|
|
if(settings.mirror == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff);
|
|
return ppu.ciram_write(addr & 0x07ff, data);
|
|
}
|
|
addr = (chr_bank * 0x2000) + (addr & 0x1fff);
|
|
Board::chr_write(addr, data);
|
|
}
|
|
|
|
auto power() -> void {
|
|
}
|
|
|
|
auto reset() -> void {
|
|
chr_bank = 0;
|
|
}
|
|
|
|
auto serialize(serializer& s) -> void {
|
|
Board::serialize(s);
|
|
s.integer(chr_bank);
|
|
}
|
|
|
|
struct Settings {
|
|
bool mirror; //0 = horizontal, 1 = vertical
|
|
} settings;
|
|
|
|
uint2 chr_bank;
|
|
};
|