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