Question

In an 8085 microprocessor, after the execution of XRA A instruction
1. the carry flag is set
2. the accumulator contains FF_H
3. the zero flag is set
4. the accumulator contents are shifted left by one bit

Answer 1

Correct Answer - Option 3 : the zero flag is set

Concept:

• In 8085 Instruction, XRA is a mnemonic that stands for “eXclusive OR Accumulator” and “R” stands for any of the following registers, or memory location M pointed by HL pair.
• R = A, B, C, D, E, H, L, or M
• This instruction is used to Ex-OR contents of R with the Accumulator. The result of the Ex-OR operation will be stored in the Accumulator.
• As R can have any of the eight values, there are eight opcodes for this type of instruction. It occupies only 1-Byte in memory.

 

e.g. MVI A, 05 H

XRA A

(0000 0101) EXOR (0000 0101) = (0000 0000)

Application:

The accumulator contains 00 H after the execution of an instruction

And Zero flag is set