DELD practical

Question 1

Flip flop def

Answer 1

an electronic device which is used to store 1-bit of information by using clock signal

Question 2

Combinational and Sequential circuits

Answer 2

Combinational - output dependent entirely on input condition (no memory elements)
ex Adder, Sub, Multiplexer, Decoder, Encoder, Comparator, Code converter
Sequential - flip flops act as memory units for storing past inputs as well
ex flipl flops, counters, shift registers

Question 3

What is a bit?

Answer 3

A bit (binary digit) is the smallest unit of data that a computer can process and store. Binary data bit.
Byte consists of 8 bits, references to computer memory are always in terms of bytes

Question 4

BCD code

Answer 4

Binary coded decimal (decimal represented as 4 bit binary)

Question 5

BCD adder

Answer 5

Adder circuit, Logic circuit (for detection - if the number is greater than 9), adder circuit (corrector - to add 0110)

Question 6

Multiplexer and uses

Answer 6

Digital switch which allows digital info from several sources to be routed onto a single output line
n = selection lines, 2^n - input lines
74151 - 8:1 MUX
Uses - data line selector, implement combinational logic circuit

Question 7

Comparator

Answer 7

simple AND, OR, NOT gates used to compare binary inputs
1 bit (2 inputs) 2 bit (4 inputs)

Question 8

Parity gen/checker

Answer 8

Detecting errors during transmission of binary info (if 0 changed to 1 or vise versa)

Question 9

Binary subtraction

Answer 9

for positive number (result): add carry 1 to the result for final result
for negative number (result): take one’s complement

Question 10

Canonical form

Answer 10

Contains all literals

Question 11

Encoders and decoders

Answer 11

Encoders - are used to convert digital data into an analogue signal, have more input lines, work on single bit at a time
Decoders - are used to convert an analogue signal into digital data, which can then be processed by a computer, more output lines, more bit and more outputs