Question

Flag Register contains data D9H. Interpret its meaning.

Answer 1

D9H = 1101 1001

The 8085 microprocessor has five flags, and their bit pattern is shown below:

Flag register	S	Z	–	CA	–	P	–	CY
Given D9H	1	1	0	1	1	0	0	1

1. The sign flag is set, which indicates that the number is negative.
2. The zero flag is set, meaning the result of the arithmetic or logical operation is zero.
3. The auxiliary carry flag is set, showing that a carry is generated from bit D₃ to D₄ during the operation.
4. The parity flag is reset, which means the result contains an odd number of 1’s.
5. The carry flag is set, indicating that a carry or borrow occurs from the most significant bit during the arithmetic operation.