What Is a Flag in a Microprocessor?

By Carl Mathie

A microprocessor is an integrated circuit that can be programmed to process data and send messages and directions to other electronic systems. They are the main features of computer processing systems. Flags are an important component of microprocessors as they register the outcomes of calculations and actions.


All microprocessors contain registers. These components register data, storing it temporarily before or after the microprocessor's calculations. For instance, the instruction register stores instruction code for the microprocessor's calculations.


Flags are a modified kind of register that record the condition of a microprocessor's calculation. For instance, a "zero status" flag is activated only when the microprocessor's calculation concludes with a "zero" status. The status of each flag determines the microprocessor's next action, thus enabling it to make decisions.

Common Flags

Some common flags in microprocessors include:"Carry" to indicate that an addition or subtraction requires a sum to be "carried" over or "borrowed.""Sign," which shows whether a calculation was positive or negative."Overflow," which is flagged when the result of a process exceeds a set word limit."Parity," which indicates that a process has produced an even number of "1"s."Zero status."