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8085 Microprocessor Flags: Correct Answer and Conceptual Explanation

8085 Microprocessor Flags: Correct Answer and Conceptual Explanation

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May 20, 2026

In the 8085 microprocessor, the correct answer is (ii) 5. The 8085 uses an 8-bit flag register, but only five flags are active and meaningful to the programmer: Sign, Zero, Auxiliary Carry, Parity, and Carry.3

Therefore, for the multiple-choice question:

How many flags does 8085 microprocessor have?

  • (i) 4
  • (ii) 5
  • (iii) 6
  • (iv) 3

the correct option is:

(ii) 5\boxed{(ii)\ 5}

These flags are automatically updated after many arithmetic and logical operations and help the processor make decisions during conditional branching such as jump-on-zero or jump-on-carry instructions.2

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩ ↩2

  3. Lecture 6 8085 Flag Register - vbspu PDF - Academic lecture notes stating that the 8085 flag register includes five flip-flops named Z, CY, S, P, and AC. ↩

  4. Intel 8085 - Wikipedia - Summarizes the 8085 architecture and lists the five flags affected by arithmetic and logical operations. ↩

Registers of 8085 Microprocessor (Status/Flags Register) - Part 1

Exam-Oriented Fact

The 8085 flag register is 8 bits wide, but only 5 bits are used as actual status flags. This distinction is often tested in MCQs.2

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

Why the answer is 5

Students are sometimes confused because the 8085 Program Status Word stores flags inside an 8-bit structure. However, the presence of 8 bit positions does not mean there are 8 implemented flags. Educational references consistently state that the 8085 has five implemented status flags.3

The five implemented flags are:

FlagSymbolPurpose
SignSSet when the result has bit 7 = 1
ZeroZSet when the result is 00H
Auxiliary CarryACSet when carry occurs from bit 3 to bit 4
ParityPSet when the result has even parity
CarryCYSet when carry out of bit 7 occurs

This is why options 4, 6, and 3 are incorrect. The accepted architectural answer is 5 flags.3

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩ ↩2

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩ ↩2

  3. Lecture 6 8085 Flag Register - vbspu PDF - Academic lecture notes stating that the 8085 flag register includes five flip-flops named Z, CY, S, P, and AC. ↩

  4. Intel 8085 - Wikipedia - Summarizes the 8085 architecture and lists the five flags affected by arithmetic and logical operations. ↩

8085 Flag Register: Used Bits vs Unused Bits

The register has 8 bit positions, but only 5 are active status flags.

The five flags in detail

Each status flag represents a specific condition after execution of an instruction.2

  1. Sign Flag (S)
    The sign flag becomes 1 if the most significant bit of the result is 1. In signed interpretation, this suggests a negative result.2

  2. Zero Flag (Z)
    The zero flag becomes 1 when the result of an arithmetic or logical operation is exactly 00H.2

  3. Auxiliary Carry Flag (AC)
    This flag becomes 1 when a carry is generated from bit 3 to bit 4. It is especially relevant in BCD arithmetic and decimal adjustment operations.2

  4. Parity Flag (P)
    The parity flag is set when the result contains an even number of 1s. This is called even parity.2

  5. Carry Flag (CY)
    The carry flag is set when an operation produces a carry out of the most significant bit in addition, or a borrow condition in subtraction.2

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩ ↩2 ↩3

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩ ↩2 ↩3 ↩4 ↩5

  3. Intel 8085 - Wikipedia - Summarizes the 8085 architecture and lists the five flags affected by arithmetic and logical operations. ↩ ↩2 ↩3 ↩4

How to Answer This MCQ Correctly

  1. 1
    Step 1

    Recognize that the question refers to the 8085 flag register, not the total number of bits in the register.2

    Footnotes

    1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

    2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

  2. 2
    Step 2

    List the standard five status flags: S, Z, AC, P, and CY.3

    Footnotes

    1. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

    2. Lecture 6 8085 Flag Register - vbspu PDF - Academic lecture notes stating that the 8085 flag register includes five flip-flops named Z, CY, S, P, and AC. ↩

    3. Intel 8085 - Wikipedia - Summarizes the 8085 architecture and lists the five flags affected by arithmetic and logical operations. ↩

  3. 3
    Step 3

    Do not confuse an 8-bit flag register with 8 implemented flags. Only five are functionally used in 8085.2

    Footnotes

    1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

    2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

  4. 4
    Step 4

    Choose option (ii) because it matches the actual number of implemented flags.

  5. 5
    Step 5

    Write: The 8085 microprocessor has 5 flags.

Common Confusion

A frequent mistake is to answer 8 because the flag register is 8 bits wide. The correct count of implemented flags in 8085 is 5, not 8.2

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

Question: How many flags does 8085 microprocessor have?

Answer: 5

Correct option: (ii) 5

Clarifications and Exam FAQs

Final answer

The 8085 microprocessor has 5 flags.3

Correct option: (ii) 5

Footnotes

  1. Flags register in 8085 Microprocessor - TutorialsPoint - Explains that the 8085 flag register has eight bit positions but only five implemented flags. ↩

  2. Flag register in 8085 microprocessor - GeeksforGeeks - Describes the 8-bit flag register and identifies the five useful flags in 8085. ↩

  3. Lecture 6 8085 Flag Register - vbspu PDF - Academic lecture notes stating that the 8085 flag register includes five flip-flops named Z, CY, S, P, and AC. ↩

Knowledge Check

Question 1 of 4
Q1Single choice

How many implemented status flags are present in the 8085 microprocessor?

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