83 lines
1.7 KiB
C++
83 lines
1.7 KiB
C++
#pragma once
|
|
|
|
#include <string>
|
|
#include <cstdint>
|
|
|
|
struct StatusFlags {
|
|
|
|
bool negative;
|
|
bool overflow;
|
|
bool reserved;
|
|
bool brk;
|
|
bool decimal;
|
|
bool interrupt;
|
|
bool zero;
|
|
bool carry;
|
|
|
|
enum StatusBits {
|
|
Negative = 0x80, // N
|
|
Overflow = 0x40, // V
|
|
Reserved = 0x20, // ignored
|
|
Break = 0x10, // B
|
|
Decimal = 0x08, // D (use BCD for arithmetic)
|
|
Interrupt = 0x04, // I (IRQ disable)
|
|
Zero = 0x02, // Z
|
|
Carry = 0x01, // C
|
|
};
|
|
|
|
StatusFlags(uint8_t value) {
|
|
negative = (value & StatusBits::Negative) != 0;
|
|
overflow = (value & StatusBits::Overflow) != 0;
|
|
reserved = (value & StatusBits::Reserved) != 0;
|
|
brk = (value & StatusBits::Break) != 0;
|
|
decimal = (value & StatusBits::Decimal) != 0;
|
|
interrupt = (value & StatusBits::Interrupt) != 0;
|
|
zero = (value & StatusBits::Zero) != 0;
|
|
carry = (value & StatusBits::Carry) != 0;
|
|
}
|
|
|
|
operator uint8_t() const {
|
|
|
|
uint8_t flags = 0;
|
|
|
|
if (negative)
|
|
flags |= StatusBits::Negative;
|
|
|
|
if (overflow)
|
|
flags |= StatusBits::Overflow;
|
|
|
|
if (reserved)
|
|
flags |= StatusBits::Reserved;
|
|
|
|
if (brk)
|
|
flags |= StatusBits::Break;
|
|
|
|
if (decimal)
|
|
flags |= StatusBits::Decimal;
|
|
|
|
if (interrupt)
|
|
flags |= StatusBits::Interrupt;
|
|
|
|
if (zero)
|
|
flags |= StatusBits::Zero;
|
|
|
|
if (carry)
|
|
flags |= StatusBits::Carry;
|
|
|
|
return flags;
|
|
}
|
|
|
|
operator std::string() const {
|
|
std::string returned;
|
|
returned += negative ? "N" : "-";
|
|
returned += overflow ? "O" : "-";
|
|
returned += reserved ? "R" : "-";
|
|
returned += brk ? "B" : "-";
|
|
returned += decimal ? "D" : "-";
|
|
returned += interrupt ? "I" : "-";
|
|
returned += zero ? "Z" : "-";
|
|
returned += carry ? "C" : "-";
|
|
return returned;
|
|
}
|
|
};
|