PSW(Program Status World)

PSW(Program Status World)

P-Parity Bit

• If a number of binary 1s in accumulator is even then this bit is set to 1(high) automatically.
• Otherwise it is reset to 0(low).

Bit-1

• This bit is reserve.

OV - Overflow flag

• Overflow occurs when the result of arithmetical operation is to large.
• So that it cannot be store in register, In that case overflow flag is set to 1(High), Otherwise it is set to 0(low).

RS0 and RS1 - Register Bank Select Bit

• This two bits are used to select one of the register bank from available 4 register bank in internal RAM location.

AC- Auxiliary Carry Flag

• It is used for BCD operation only this bit set when their is carry generated from low bit to higher bit. 

CY- Carry Flag

• This flag is set to 1 whenever their is carry generated from last bit.
•  Carry flag is used during addition and subtraction operation.