Question

Consider the flags in flag Register from left to right :
A. S

B. Z

C. AC

D. P

E. CY

Choose the correct answer from the options given below :

• A. A, B, C, D, E
• B. A, B, D, C, E
• C. C, D, E, A, B
• D. C, D, A, B, E

Hint:

Use the mnemonic "S-Z-X-AC-X-P-X-CY". Just remember that Sign is always the MSB and Carry is always the LSB in almost every standard microprocessor architecture.

Answer 1

The Correct Option is A

In the 8085 microprocessor, the flag register is an 8-bit register where 5 bits represent specific status flags. "Left to right" refers to moving from the Most Significant Bit (MSB, Bit 7) to the Least Significant Bit (LSB, Bit 0). 1. Bit Map of the 8085 Flag Register:
• Bit 7 (S - Sign Flag): The leftmost flag.
• Bit 6 (Z - Zero Flag): Immediately to the right of Sign.
• Bit 5: Undefined ($X$).
• Bit 4 (AC - Auxiliary Carry Flag): In the middle.
• Bit 3: Undefined ($X$).
• Bit 2 (P - Parity Flag): Second to last flag.
• Bit 1: Undefined ($X$).
• Bit 0 (CY - Carry Flag): The rightmost flag. 2. Final Sequence: Reading from MSB to LSB (Left to Right), we find the flags in the order: S (A), Z (B), AC (C), P (D), CY (E).