Flag register of 8086 microprocessor Krish Advani 17/04/2013 Engineering The Flag Register of Intel 8086 microprocessor is divided into two parts: Condition Codes or Status Flags Machine Control Flags Carry, Parity, Auxiliary Carry, Zero, Sign and Overflow Flags are included in Status Flags Direction, Trap, Interrupt flags are included in Machine control flag. In case of signed arithmetic operation, the overflow flag is set, if the result is too large to fit in the number of bits available to accommodate it. If interrupt flag is set, maskable interrupt INTR of 8086 is enabled and if reset then interrupt is disabled. The trap flag puts microprocessor in single step execution allowing programmers to debug. The direction flag is used in string operation. If the flag is set then the process related to the string will start from the higher byte to the lower byte, and if it is reset the from lower byte to higher byte. The rest of the flags are the same as of the 8085 microprocessor.