bsnes/higan/fc/memory/memory.cpp

42 lines
935 B
C++
Executable File

#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
uint8 Bus::read(uint16 addr) {
uint8 data = cartridge.prg_read(addr);
if(addr <= 0x1fff) data = cpu.ram_read(addr);
else if(addr <= 0x3fff) data = ppu.read(addr);
else if(addr <= 0x4017) data = cpu.read(addr);
if(cheat.override[addr]) {
for(unsigned n = 0; n < cheat.size(); n++) {
if(cheat[n].addr == addr) {
if(cheat[n].comp > 255 || cheat[n].comp == data) {
data = cheat[n].data;
break;
}
}
}
}
return data;
}
void Bus::write(uint16 addr, uint8 data) {
cartridge.prg_write(addr, data);
if(addr <= 0x1fff) return cpu.ram_write(addr, data);
if(addr <= 0x3fff) return ppu.write(addr, data);
if(addr <= 0x4017) return cpu.write(addr, data);
}
}