bsnes/higan/fc/memory/memory.cpp

35 lines
796 B
C++

#include <fc/fc.hpp>
namespace Famicom {
Bus bus;
//$0000-07ff = RAM (2KB)
//$0800-1fff = RAM (mirror)
//$2000-2007 = PPU
//$2008-3fff = PPU (mirror)
//$4000-4017 = APU + I/O
//$4018-ffff = Cartridge
auto Bus::read(uint16 addr) -> uint8 {
uint8 data = cartridge.readPRG(addr);
if(addr <= 0x1fff) data = cpu.readRAM(addr);
else if(addr <= 0x3fff) data = ppu.readIO(addr);
else if(addr <= 0x4017) data = cpu.readIO(addr);
if(cheat.enable()) {
if(auto result = cheat.find(addr, data)) return result();
}
return data;
}
auto Bus::write(uint16 addr, uint8 data) -> void {
cartridge.writePRG(addr, data);
if(addr <= 0x1fff) return cpu.writeRAM(addr, data);
if(addr <= 0x3fff) return ppu.writeIO(addr, data);
if(addr <= 0x4017) return cpu.writeIO(addr, data);
}
}