GATE ECE 2017 Set 1 | Instruction Set and Programming with 8085 Question 2 | Microprocessors

GATE ECE 2017 Set 1

MCQ (Single Correct Answer)

-0.6

The following five instructions were executed on an 8085 microprocessor.
MVI A, 33H
MVI B, 78H
ADD B
CMA
ANI 32H

The Accumulator value immediately after the execution of the fifth instruction is

00H

10H

11H

32H

GATE ECE 2016 Set 1

MCQ (Single Correct Answer)

-0.6

In an 8085 system, a PUSH operation requires more clock cycles than a POP operation. Which one of the following options is the correct reason for this?

For POP, the data transceivers remain in the same direction as for instruction fetch (memory to processor), whereas for PUSH their direction has to be reversed.

Memory write operations are slower than memory read operations in an 8085 based system.

The stack pointer needs to be pre-decremented before writing registers in a PUSH, whereas a POP operation uses the address already in the stack pointer.

Order of registers has to be interchanged for a PUSH operation, whereas POP uses their natural order.

GATE ECE 2014 Set 4

MCQ (Single Correct Answer)

-0.6

An 8085 microprocessor executes “STA 1234H” with starting address location 1FFEH (STA copies the contents of the Accumulator to the 16-bit address location). While the instruction is fetched and executed, the sequence of values written at the address pins $${A_{15}}$$ − $${A_{8}}$$ is

1FH, 1FH, 20H, 12H

1FH, FEH, 1FH, FFH, 12H

1FH, 1FH, 12H, 12H

1FH, 1FH, 12H, 20H, 12H

GATE ECE 2011

MCQ (Single Correct Answer)

-0.6

An 8085 assembly language program is given below. Assume that the carry flag is initially unset. The content of the accumulator after the execution of the program is
MVI A,07H
RLC
MOV B,A
RLC
RLC
ADD B
RRC

8C H

64 H

23 H

15 H