•OV: (Overflow flag) is set after an addition or
subtraction operation if there was an
arithmetic overflow. Results greater than +127 or
less than –128 will set OV bit.
•P: (Parity Bit) automatically set or cleared each
machine cycle to establish even parity
with the accumulator. Parity bit is most commonly
used in conjunction with serial port routines to include a parity bit before or after the transmission.
•RS1 & RS0 are used
to select different register banks.