sign flag parity flag zero flag
there are 5 flags of intel 8085 are: Carry flag(CY), parity flag(P), Auxiliary Carry flag(AC), Zero Flag(Z), Sign flag(S).
In the 8085 microprocessor, the status flags are specific bits in the flag register that indicate the outcome of arithmetic and logical operations. There are five main flags: the Sign Flag (S), Zero Flag (Z), Auxiliary Carry Flag (AC), Parity Flag (P), and Carry Flag (CY). The Sign Flag indicates the sign of the result, the Zero Flag indicates if the result is zero, the Auxiliary Carry Flag is used for BCD operations, the Parity Flag indicates if the number of set bits is even or odd, and the Carry Flag indicates an overflow in arithmetic operations. These flags are essential for decision-making in program execution and control flow.
In the 8085 microprocessor, the Arithmetic Logic Unit (ALU) affects five flags in the status register: Sign Flag (S), Zero Flag (Z), Auxiliary Carry Flag (AC), Parity Flag (P), and Carry Flag (CY). The Sign Flag indicates the sign of the result; the Zero Flag is set if the result is zero; the Auxiliary Carry Flag is used for BCD operations; the Parity Flag indicates whether the number of 1s in the result is even or odd; and the Carry Flag indicates an overflow in arithmetic operations. These flags help in decision-making for subsequent operations and control flow in programs.
The Program Status Word (PSW) for the 8085 and 8086 microprocessors consists of various flags that indicate the status of operations. In the 8085, the flags include the Sign Flag (S), Zero Flag (Z), Auxiliary Carry Flag (AC), Parity Flag (P), and Carry Flag (CY). For example, if an operation results in a negative value, the Sign Flag is set, while if the result is zero, the Zero Flag is set. In 8086, the PSW includes similar flags but adds the Overflow Flag (OF), which indicates an overflow in signed arithmetic operations.
In the 8085 microprocessor, DAD (Double Add) is an instruction that adds the contents of a specified 16-bit register pair (HL, BC, or DE) to the contents of the accumulator (A) and stores the result back in the 16-bit register pair. The flags affected by the DAD instruction are the Carry flag (CY) and the Parity flag (P). The Zero flag (Z) and Sign flag (S) remain unaffected. Additionally, the Auxiliary Carry flag (AC) is also not affected by this operation.
In the 8085 microprocessor, the Program Status Word (PSW) contains important flags that reflect the state of the processor. Different instructions can affect these flags, such as the Zero Flag, Sign Flag, Carry Flag, and Parity Flag. For example, arithmetic operations like addition or subtraction can set or reset these flags based on the result of the operation. Consequently, the PSW is essential for conditional branching and decision-making within programs, as it provides the necessary status information determined by the executed instructions.
The 8085 microprocessor has 5 flags: 1. Zero flag: The zero flag is set, when the ALU operation results a zero . 2. Carry flag: If an arithmetic operations results in a carry, this flag is set. 3. Parity flag: This flag is set, when an arithmetic or logical operation results in a data, which has even number of 1s. If otherwise, it is reset. 4. Sign flag: After the execution of an arithmetic or logic operations, if D7 bit of the accumulator is 1, it indicates a negative number and this flag is set. If otherwise, it is reset. 5. Auxiliary Carry flag: used for BCD Operations, During the BCD operations, if D3 bit producing the carry then the AC bit set as1, otherwise the bit is 0. 6. Carry Flag: when a carry is generated by digit D7, then the carry flag set as 1, otherwise the bit will be 0.
Flags are microprocessor dependent. ie flags are different for different microprocessors. Flag represents the status ( & Type) of the operation performed. Ex: In terms of 8085 we have 5 flags : Zero, Carry, Ac Carry, Parity, Sign Flag register is of 8 bits in this case. These flags can also be used for logic implementation.
Calls Which are based on conditions like flag status are called conditional flags ex:cc(Call if carry) cz(Call if zero) Calls Which are independent of any kind of conditions, are called unconditional call Ex:Call 2030
Microprocessors are equipped with flags which are used for letting one know some information such as for instance whether the result of any operaton was positive or negative,the result contains the even parity bits or odd,whether carry bits are generated or not.all these help the programmer out in performing further opertaions.different microprocessors contain different types and differnet number of flags.for instance INTEL 8085 contains 5 flags. AUX CARRY FLAG,ZERO FLAG,SIGN FLAG,PARITY FLAG,CARRY FLAG Anand bhat(mca@kiit-870024)
The ORA A instruction does not change the contents of the accumulator. It does, however, set flags to indicate something about the value of the accumulator. In particular, Z means the result is zero, N means it is negative, and P means it has an odd number of ones.