GATE ECE
Microprocessors
Instruction Set and Programming with 8085
Previous Years Questions
Marks 1
The clock frequency of an 8085 microprocessor is 5 MHz. If the time required to execute an instruction is 1.4 $$\mu $$s,
then the number of T-states ...
In an 8085 microprocessor, the contents of the accumulator and the carry flag are A7 (in hex) and 0, respectively. If the instruction RLC is executed,...
Which one of the following 8085 microprocessor programs correctly calculates the product of two 8-bit numbers stored in registers B and C?
In an 8085 microprocessor, which one of the following instructions changes the content of the accumulator?
In an 8085 microprocessor, the shift registers which store the result of an addition and the overflew bit are, respectively.
For 8085 microprocessor, the following program is executed.
At the end of program, accumulator contains...
An instruction used to set the carry flag in a computer can be classified as
The following instructions have been executed by an 8085 $$\mu $$P
From which address will be text instruction be fetched?...
The following sequence of instructions are executed by an 8085 microprocessor:
1000: LXI SP< 27FF
1003: CALL 1006
1006: POP H
The contents of t...
The total number of memory accesses involved (inclusive of the op-code fetch) when an 8085 processor executes, the instruction LDA 2003 is
An 'Assembler' for a microprocessor a used for
In a microprocessor, the register which holds the address of the next instruction to be fetched is
The following program is run on 8085 microprocessor:
At the completion of execution of the program, the program Counter of the 8085 contains _______...
In a microprocessor system, the stack is used for
In register index addressing mode the effective address is given by
Marks 2
The following five instructions were executed on an 8085 microprocessor.
MVI A, 33H
MVI B, 78H
ADD B
CMA
ANI 32H
The Accumulator value immedia...
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 thi...
An 8085 microprocessor executes “STA 1234H” with starting address location 1FFEH (STA copies the contents of the
Accumulator to the 16-bit address lo...
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...
For the 8085 assembly language program given below, the content of the accumulator after the executions of the program is
3000 MVI A, 45H
3002 MOV...
An 8085 executes the following instructions
2710 LXI H, 30A0H
DAD H
PCHL
All addresses and constants are in Hex. Let PC be the contents of the p...
An 8085 assembly language program is given below.
Line 1: MVI A, B5H
2: MVI B, 0EH
3: XRI 69H
4: ADD B
5: ANI 9BH
6: CPI 9FH
7: STA 3010H
8:...
An 8085 assembly language program is given below.
Line 1: MVI A, B5H
2: MVI B, 0EH
3: XRI 69H
4: ADD B
5: ANI 9BH
6: CPI 9FH
7: STA 3010H
8:...
Following is the segment of a 8085 assembly Language program:
LXI SP, EFFF H
CALL 3000 H
3000H: LXI H, 3CF4H
PUSH PSW
SPHL
POP PSW
RET
On c...
Consider an 8085 microprocessor system
The following program starts at locaton 0100H.
LXI SP, 00FF
LXI H, 0107
MVI A, 20H
SUB M
The contents ...
Consider an 8085 microprocessor system
If in addition following code exists from 0109H onwards ORI 40H, ADD M What will be the result in the accumu...
The number of memory cycles required to execute the following 8085 instructions
(I.) LDA 3000H
(II.) LXI D, FOF 1H
Would be
It is desired to multiply the numbers 0AH by 0BH and store the result in the accumulator. The numbers are available in registers B and C respectively....
Consider the sequence of 8085 instructions given below.
LXI H, 9258
MOV A, M
CMA
MOV M, A
Which one of the following is performed by this sequ...
In an 8085 microprocessor, the instruction CMP B has been executed while the
content of the accumulator is less than that of register B. As a result
...
The contents of Register (B) and Accumulator (A) of 8085 microprocessor are 49H and 3AH respectively. The contents of A and the status of carry flag (...
Consider the following assembly language program.
The execution of the above program in an 8085 microprocessor will result in
...
Marks 5
Write down the sequence of Instructions which are actually (till HLT instruction), if the program begins with the location 1FF5H.
...
The program given below is run on an 8085 based microcomputer system. Determine the contents of the registers: PC, SP, B,
C, H, L after a half instr...