mirror of https://github.com/bsnes-emu/bsnes.git
50 lines
1.1 KiB
C++
50 lines
1.1 KiB
C++
auto Cartridge::MBC5::readIO(uint16 addr) -> uint8 {
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if((addr & 0xc000) == 0x0000) { //$0000-3fff
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return cartridge.readROM(addr);
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}
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if((addr & 0xc000) == 0x4000) { //$4000-7fff
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return cartridge.readROM(rom.select << 14 | (uint14)addr);
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}
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if((addr & 0xe000) == 0xa000) { //$a000-bfff
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if(ram.enable) return cartridge.readRAM(ram.select << 13 | (uint13)addr);
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return 0xff;
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}
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return 0xff;
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}
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auto Cartridge::MBC5::writeIO(uint16 addr, uint8 data) -> void {
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if((addr & 0xe000) == 0x0000) { //$0000-1fff
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ram.enable = data.bits(0,3) == 0x0a;
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return;
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}
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if((addr & 0xf000) == 0x2000) { //$2000-2fff
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rom.select.byte(0) = data;
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return;
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}
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if((addr & 0xf000) == 0x3000) { //$3000-3fff
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rom.select.byte(1) = data.bit(0);
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return;
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}
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if((addr & 0xe000) == 0x4000) { //$4000-5fff
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ram.select = data.bits(0,3);
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return;
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}
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if((addr & 0xe000) == 0xa000) { //$a000-bfff
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if(ram.enable) cartridge.writeRAM(ram.select << 13 | (uint13)addr, data);
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return;
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}
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}
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auto Cartridge::MBC5::power() -> void {
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rom.select = 0x001;
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ram.enable = false;
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ram.select = 0x00;
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}
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