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Flag/Condition Code Register
The flag/condition code register consists of individual bits that are set or cleared depending on the result of an operation. These bits can remember processing states between instructions.
Different instructions affect the condition code register in different ways. Depending on the processor type, a data transfer instruction may not affect any flags, while an addition may affect several flags.
The condition code bits can remember information about an instruction. For example if during an addition the result grew too big to fit in the destination register a carry (unsigned) would result. The fact that this carry occurred could be remembered by a condition code register bit. The bit remains in the new state until another instruction that affects the carry bit in the condition code register executes.
Not all instructions affect condition code register bits.