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Free download in PDF Microcontrollers and Applications Short Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
41
What is the required baud rate for an efficient operation of serial port devices in 8051 microcontroller?
[A]
1200
[B]
2400
[C]
4800
[D]
9600
42
Which port does not represent quasi-bidirectional nature of I/O ports in accordance to the pin configuration of 8051 microcontroller?
[A]
Port 0 (Pins 32-39)
[B]
Port 1 (Pins 1-8)
[C]
Port 2 (Pins 21-28)
[D]
Port 3 (Pins 10-17)
Answer: Port 0 (Pins 32-39)
43
Where should the pin 19 (XTAL1), acting as an input of inverting amplifier as well as part of an oscillator circuit, be connected under the application of external clock?
[A]
to XTAL2
[B]
to Vcc
[C]
to GND
[D]
to ALE
44
Which mode of timer 2 allow to hold the reload values with an assistance of RCAP2H & RCAP2L register pair?
[A]
8 bit auto-reload mode
[B]
16 bit auto reload mode
[C]
8 bit capture mode
[D]
16 bit capture mode
Answer: 16 bit auto reload mode
45
Which registers are supposed to get copied into RCAP2H & RCAP2L respectively due to the transition at 8052 T2EX pin in the capture mode operation?
[A]
TH0 & TH1
[B]
TH1 & TH1
[C]
TH2 & TH2
[D]
All of the above
46
Which timer is attributed to the register pair of RCAP2H & RCAP2L for capture mode operation?
[A]
Timer 0
[B]
Timer 1
[C]
Timer 2
[D]
Timer 3
47
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
48
What is the maximum capability of addressing the off-chip data memory & off-chip program memory in a data pointer?
[A]
8K
[B]
16K
[C]
32K
[D]
64K
49
Which instruction find its utility in loading the data pointer with 16 bits immediate data?
[A]
MOV
[B]
INC
[C]
DEC
[D]
ADDC
50
Which commands are used for addressing the off-chip data and associated codes respectively by data pointer?
[A]
MOVX & MOVC
[B]
MOVY & MOVB
[C]
MOVZ & MOVA
[D]
MOVC & MOVY
51
Which locations of 128 bytes on-chip additional RAM are generally reserved for special functions?
[A]
80H to 0FFH
[B]
70H to 0FFH
[C]
90H to 0FFH
[D]
60H to 0FFH
52
It is possible to set the auxiliary carry flag while performing addition or subtraction operations only when the carry exceeds _______
[A]
1st bit
[B]
2nd bit
[C]
3rd bit
[D]
4th bit
53
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
54
Which flags represent the least significant bit (LSB) and most significant bit (MSB) of Program Status Word (PSW) respectively?
[A]
Parity Flag & Carry Flag
[B]
Parity Flag & Auxiliary Carry Flag
[C]
Carry Flag & Overflow Flag
[D]
Carry Flag & Auxiliary Carry Flag
Answer: Parity Flag & Carry Flag
55
Which bit/s play/s a significant role in the selection of a bank register of Program Status Word (PSW)?
[A]
RS1
[B]
RS0
[C]
Both a & b
[D]
None of the above
56
What is the default value of stack once after the system undergoes the reset condition?
[A]
07H
[B]
08H
[C]
09H
[D]
00H
57
Which among the below mentioned functions does not belong to the category of alternate functions usually performed by Port 3 (Pins 10-17)?
[A]
External Interrupts
[B]
Internal Interrupts
[C]
Serial Ports
[D]
Read / Write Control signals
Answer: Internal Interrupts
58
What is the constant activation rate of ALE that is optimized periodically in terms of an oscillator frequency?
[A]
1 / 8
[B]
1 / 6
[C]
1 / 4
[D]
1 / 2
59
Which output control signal is activated after every six oscillator periods while fetching the external program memory and almost remains high during internal program execution?
[A]
ALE
[B]
PSEN
[C]
EA
[D]
All of the above
60
Which memory allow the execution of instructions till the address limit of 0FFFH especially when the External Access (EA) pin is held high?
[A]
Internal Program Memory
[B]
External Program Memory
[C]
Both a & b
[D]
None of the above
Answer: Internal Program Memory