Microprocessors and Microcontrollers (3160914) MCQs

MCQs of 8051 Microcontroller Architecture

Showing 1 to 10 out of 89 Questions
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1.

 8051 microcontrollers are manufactured by which of the following companies?

(a)

Atmel
(b)

Philips
(c)

Intel
(d)

 All of the mentioned
Answer:

Option (d)

2.

AT89C2051 has RAM of:

(a)

128 bytes
(b)

256 bytes
(c)

64 bytes
(d)

512 bytes
Answer:

Option (a)

3.

8051 series has how many 16 bit registers?

(a)

2
(b)

3
(c)

1
(d)

0
Answer:

Option (a)

4.

When 8051 wakes up then 0x00 is loaded to which register?

(a)

PSW
(b)

SP
(c)

PC
(d)

None of the mentioned
Answer:

Option (c)

5.

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

(a)

PSW
(b)

SP
(c)

DPTR
(d)

PC
Answer:

Option (a)

6.

 How are the status of the carry, auxiliary carry and parity flag affected if the write instruction
MOV A,#9C    ADD A,#64H

(a)

CY=0,AC=0,P=0
(b)

 CY=1,AC=1,P=0
(c)

CY=0,AC=1,P=0
(d)

CY=1,AC=1,P=1
Answer:

Option (b)

7.

 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
Answer:

Option (d)

8.

 If we push data onto the stack then the stack pointer

(a)

increases with every push
(b)

 decreases with every push
(c)

increases & decreases with every push
(d)

 none of the mentioned
Answer:

Option (a)

9.

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
Answer:

Option (b)

10.

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

(a)

8 bytes
(b)

 32 bytes
(c)

16 bytes
(d)

 128 bytes
Answer:

Option (c)

Showing 1 to 10 out of 89 Questions
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