Instruction Set and Programming with 8085 · Microprocessors · GATE ECE

In an 8085 microprocessor, the number of address lines required to access a 16 K bytes memory bank is

$\_\_\_\_$ .

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 needed for executing the instruction is

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, then the contents of the accumulator (in hex) and the carry flag, respectively, will be

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, the shift registers which store the result of an addition and the overflew bit are, respectively.

In an 8085 microprocessor, which one of the following instructions changes the content of the accumulator?

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 total number of memory accesses involved (inclusive of the op-code fetch) when an 8085 processor executes, the instruction LDA 2003 is

The following sequence of instructions are executed by an 8085 microprocessor:
1000: LXI SP< 27FF
1003: CALL 1006
1006: POP H

The contents of the stack pointer (SP) and the HL register pair on completion or execution of these instructions are.

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 ________ and the Stack Pointer contains ________.

In a microprocessor system, the stack is used for

In register index addressing mode the effective address is given by

The content of the registers are $R_1=25 \mathrm{H}, R_2=30 \mathrm{H}$ and $R_3 =40 \mathrm{H}$. The following machine instructions are executed.

$$ \begin{aligned} & \operatorname{PUSH}\left\{R_1\right\} \\ & \operatorname{PUSH}\left\{R_2\right\} \\ & \operatorname{PUSH}\left\{R_3\right\} \\ & \operatorname{POP}\left\{R_1\right\} \\ & \operatorname{POP}\left\{R_2\right\} \\ & \operatorname{POP}\left\{R_3\right\} \end{aligned} $$

After execution, the content of registers $R_1, R_2, R_3$ are

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

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?

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

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

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 B, A
3003 STC
3004 CMC
3005 RAR
3006 XRA B

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 program counter and HL be the contents of the HL register pair just after executing PCHL.

Which of the following statements is correct.

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: HLT

The contents of the accumulator just after execution of the ADD instruction in line 4 will be

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: HLT

After execution of line of the program, the status of the CY and Z flags will be

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 completion of RET execution, the contents of SP is

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 of accumulator wnen the program counter reaches 0109H is

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 accumulator after the last instruction is executed

The number of memory cycles required to execute the following 8085 instructions
(I.) LDA 3000H
(II.) LXI D, FOF 1H
Would be

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 sequence?

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. A part of the 8085 program for this purpose is given below:
MVI A, 00H
LOOP:.........
...............
HLT END

The sequence of instruction to be complete the program would be

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 (CY) and sign flag (S) after executing SUB B instructions are

Consider the following assembly language program. The execution of the above program in an 8085 microprocessor will result in

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 instruction is executed.
LOC
2000 START: LXI SP, 1000H
LXI H, 2F37 H
XRA A
MOV A, H
INX H
PUSH H
CZ 20 FF H JMP 3000 H
HLT
20FF ADD H
RZ
POP B
PUSH B
RNZ
HLT