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8051 Microcontroller

Total questions: 40

Worksheet time: 20mins

Name
Class
Date
1.

When the microcontroller executes some arithmetic operations, then the flag bits of which register are affected?

a)

PSW

b)

SP

c)

DPTR

d)

PC

2.

Which operator is the most important while assigning any instruction as register indirect instruction?

a)

#

b)

@

c)

*

d)

&

3.

Which of the following comes under the indexed addressing mode?

a)

MOVX A, @DPTR

b)

MOVC @A+DPTR,A

c)

MOV A,R0

d)

MOV @R0,A

4.

To select Register Bank 1, RS1-RS0 Should be

a)

0 0

b)

0 1

c)

1 0

d)

1 1

5.

Give the internal RAM size in 8051.

a)

8-bit

b)

1-Byte

c)

4 KB

d)

128 Byte

6.

Number of register banks in 8051

a)

8

b)

7

c)

4

d)

10

7.

ROM memory size placed on chip?

a)

64Kbytes

b)

4Kbytes

c)

256 Bytes

d)

128 bytes

8.

How many SFR registers are present in memory

a)

10

b)

12

c)

11

d)

21

9.

How many ports does a 8051 microcontroller have?

a)

8

b)

4

c)

2

d)

1

10.

The size of PC (Program Counter) of 8051 microcontroller is

a)

16 bit

b)

8 bit

c)

32 bit

d)

4 bit

11.

What is the bit size of the 8051 microcontroller

a)

8

b)

16

c)

32

d)

64

12.

The total external data memory that can be interfaced to the 8051 is:

a)

32K

b)

64K

c)

128K

d)

256K

13.

Which of the following are 8 bit registers?

a)

PSW

b)

DPTR

c)

ACCUMULATOR (A reg)

d)

Program Counter

14.

Total number of Interrupt sources of 8051 MC is ______

a)

2

b)

4

c)

6

d)

5

15.

How many serial port available in 8051

a)

1

b)

2

c)

3

d)

4

16.

Which is the multifunctional port of 8051 microcontroller?

a)

Port 0

b)

Port 3

c)

Port 2

d)

Port 1

17.

Identify the addressing Mode of instruction MOV A,@R0

a)

Indexed

b)

indirect

c)

direct

d)

register

18.

Which is the instruction that branches when A==0?

a)

JC

b)

JMP

c)

JZ

d)

DJNZ

19.

The number of Timers in 8051 are

a)

Three

b)

Two

c)

One

d)

Four

20.

How many bytes of bit addressable memory is present in 8051 based microcontrollers?

a)

8 bytes

b)

32 bytes

c)

16 bytes

d)

28 bytes

21.

On power-up, the 8051 uses which RAM locations for register R0- R7

a)

00-2F

b)

00-07

c)

00-7F

d)

00-0F

22.

MOV A, @ R1 will:

a)

copy R1 to the accumulator

b)

copy the accumulator to R1

c)

copy the contents of memory whose address is in R1 to the accumulator

d)

copy the accumulator to the contents of memory whose address is in R1

23.

An alternate function of port pin P3.4 in the 8051 is:

a)

Timer 0

b)

Timer 1

c)

interrupt 0

d)

interrupt 1

24.

It is the brain of a microcontroller.

a)

RAM

b)

CPU

c)

ROM

d)

EEPROM

25.

How are the bits of the register PSW affected if we select Bank2 of 8051?

a)

PSW.5=0 and PSW.4=1

b)

PSW.2=0 and PSW.3=1

c)

PSW.3=1 and PSW.4=1

d)

PSW.3=0 and PSW.4=1

26.

 EA\overline{EA}  is held _____ , to access external ROM

a)

High

b)

Low

c)

High Impedance State

d)

None

27.

Give the starting address of Bank 1?

a)

00H

b)

07H

c)

08H

d)

None of the above

28.

PSW stands for _________________________

a)

Program state word register

b)

Progress state word register

c)

Progress status word register

d)

Program status word register

29.

How many register bank in 8051?

a)

1

b)

2

c)

3

d)

4

30.

Each register bank consist of how many registers?

a)

4

b)

8

c)

16

d)

32

31.

If carry generates from bit D6 to D7 but not from D7 to out then _____________flag set

a)

Parity (P)

b)

Carry (CY)

c)

Auxillary carry (AC)

d)

Overflow (OV)

32.

Special function Register (SFR) address of PSW is ______________________

a)

A0H

b)

B0H

c)

E0H

d)

D0H

33.

MOV A , # 0FH

INC A


A = ?

a)

17

b)

18

c)

10

d)

13

34.

What kind of instructions usually affect the program counter?

a)

Call & Jump

b)

Call & Return

c)

Push & Pop

d)

Return & Jump

35.

Which register bank is supposed to get selected if the values of register bank select bits RS1 & Rs0 are detected to be ‘1’ & ‘0’ respectively?

a)

Bank 0

b)

Bank 1

c)

Bank 2

d)

Bank 3

36.

Which instruction find its utility in loading the data pointer with 16 bits immediate data?

a)

MOV

b)

INC

c)

DEC

d)

ADDC

37.

Which among the below stated registers does not belong to the category of special function registers?

a)

TCON & TMOD

b)

TH0 & TL0

c)

P0 & P1

d)

SP & PC

38.

How does the processor respond to an occurrence of the interrupt?

a)

By Interrupt Service Subroutine

b)

By Interrupt Status Subroutine

c)

By Interrupt Structure Subroutine

d)

By Interrupt System Subroutine

39.

Which special function register play a vital role in the timer/counter mode selection process by allocating the bits in it?

a)

TMOD

b)

TCON

c)

SCON

d)

PCON

40.

Which pin in the shift register mode (Mode 0) of serial communication allows the data transmission as well as the reception?

a)

TXD

b)

RXD

c)

RB8

d)

REN