Expalin johnson counter, Computer Engineering

Assignment Help:

Write short note on the Johnson counter.

Ans:

 Johnson Counter: It is a synchronous counter, where all flip-flops are clocked concurrently and the clock pulses drive the clock input of all the flip-flops together therefore there is no propagation delay. Fig.(a) demonstrates the circuit of Johnson counter. In case of the  D  input  of  FF0  is  driven  by  Q‾ output  of  FF3, that is, the complement of the output of the final flip flop is fed to the D of FF0. Feedback of this arrangement generates the sequence of states illustrated in Table no.1. The 4 bit sequence has a total of 8 states (there is n bit sequence will have 2n states). Therefore an n bit Johnson counter will have a modulus of 2n.

The Q output of all stage feeds the D input of next stage. Although the Q‾ output of the final stage feeds the D input of primary stage. The counter fills up along with 1's from left to right and after that fills up 0s again as demonstrated in Table no.2. Fig. (b) Demonstrates the wave shapes/timing diagram of 4 bit Johnson counter.

563_Logic Diagram of Johnson counter.png

Fig.(a) Logic Diagram of Johnson counter

Clock Pulse

Q0

Q1

Q2

Q3

0

0

0

0

0

1

1

0

0

0

2

1

1

0

0

3

1

1

1

0

4

1

1

1

1

5

0

1

1

1

6

0

0

1

1

7

0

0

0

1

Table no.1 Sequence of states of 4 bit Johnson Counter

2108_Timing Diagram of 4-bit Johnson Counter.png

Fig.(b) Timing Diagram of 4-bit Johnson Counter


Related Discussions:- Expalin johnson counter

Why smtp used as transfer protocol for web pages, Can SMTP be used as trans...

Can SMTP be used as transfer protocol for Web pages? Why? SMTP is an easy mail transfer protocol. This uses ASCII text for all communications. SMTP needs reliable delivery- the

Recombination - canonical genetic algorithm, Recombination: Therefore...

Recombination: Therefore during the selection and mating process then the GA repeatedly lines up pairs of individuals for reproduction. Hence the next question is how to gener

Types of security features employed in client server network, What are the ...

What are the types of security features employed in client server kinds of network? Security features employed in Client-Server types of network are as illustrated below: a)

Features added in message passing interface-2, Q. Show the Features added i...

Q. Show the Features added in message passing interface-2 Input/output Single-sided operations for remote memory access Binding for C++ Dynamic process managem

Explain extended binary coded decimal interchange code, Q. Explain Extended...

Q. Explain Extended Binary Coded Decimal Interchange Code? Extended Binary Coded Decimal Interchange Code (EBCDIC) is a character-encoding format employed by IBM mainframes. It

Data structure, what are the fundamental data structures

what are the fundamental data structures

Advantages of e-commerce, One of the resources we used was Ajeet Khurana's ...

One of the resources we used was Ajeet Khurana's article that talks about the advantages of e-commerce. It was helpful to gain some background on the variety of benefits the electr

Explain about the voice recognition device, Explain about the Voice recogni...

Explain about the Voice recognition device Blind and partially-sighted people can communicate with a computer using microphone and software (keyboard and touch screens can't be

How can system improved when free lines are available, How can system impro...

How can system improved if one arrive at the probability of availability of free lines during the busy hour? Improvement can be made when the system is act as a loss system in

What are function modules, What are function modules? Function m...

What are function modules? Function modules are general-purpose library routines that are available system-wide.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd