MCQs on AVR microcontroller, 8255, 8051 – NPTEL assignment

Last updated on March 10th, 2022 at 05:35 pm

6 ) Why interface chips are necessary in a microcontroller-based system?

a) To resolve the speed problem
b) To synchronize the data transfers between the CPU and the I/O device
c) To synchronize the data transfers between the CPU and the I/O device, as well as to resolve the speed problem
d) None of the given options

Accepted Answers:
To synchronize the data transfers between the CPU and the I/O device, as well as to resolve
the speed problem

7 ) Which of the following can be associated with bouncing contacts?

a) Push-button switches
b) Toggle switches
c) Both push-button switches and toggle switches
d) Neither push-button switches nor toggle switches

Accepted Answers:
Both push-button switches and toggle switches

8 ) Which of the following is a hardware solution to suppress a switch bounce in a microcontroller-based system?

a) An RC time constant whose value is smaller than the switch bounce
b) An LC time constant whose value is smaller than the switch bounce
c) An RC time constant whose value is larger than the switch bounce
d) An LC time constant whose value is larger than the switch bounce

Accepted Answers:
An RC time constant whose value is larger than the switch bounce

9 ) The term DIP in the phrase ‘DIP switch’ stands for

a) Double In-lane Package
b) Double In-line Package
c) Dual In-line Package
d) Dual In-lane Package

Accepted Answers:
Dual In-line Package

10) With respect to 8255 Programmable Peripheral Interface (PPI), which of the following statement(s) are correct?
1. Mode 0: Any port can be used as input/output ports.
2. Mode 1: Both Port A and B can be used as input/output ports.
3. Mode 2: Port B can be used either in Mode 0 or Mode 1.

a) Only 1 is correct.
b) Only 2 is correct.
c) Only 3 is correct.
d) All 1, 2 and 3 are correct.

Accepted Answers:
All 1, 2 and 3 are correct.