bsnes/higan/sfc/alt/cpu/memory.cpp

45 lines
870 B
C++

auto CPU::pio() -> uint8 {
return status.pio;
}
auto CPU::joylatch() -> bool {
return status.joypad_strobe_latch;
}
auto CPU::interrupt_pending() -> bool {
return false;
}
auto CPU::port_read(uint8 port) -> uint8 {
return port_data[port & 3];
}
auto CPU::port_write(uint8 port, uint8 data) -> void {
port_data[port & 3] = data;
}
auto CPU::op_io() -> void {
add_clocks(6);
}
auto CPU::op_read(uint addr) -> uint8 {
regs.mdr = bus.read(addr, regs.mdr);
add_clocks(speed(addr));
return regs.mdr;
}
auto CPU::op_write(uint addr, uint8 data) -> void {
add_clocks(speed(addr));
bus.write(addr, regs.mdr = data);
}
auto CPU::speed(uint addr) const -> uint {
if(addr & 0x408000) {
if(addr & 0x800000) return status.rom_speed;
return 8;
}
if((addr + 0x6000) & 0x4000) return 8;
if((addr - 0x4000) & 0x7e00) return 6;
return 12;
}