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

What do you mean by consumer behavior, What do you mean by consumer behavio...

What do you mean by consumer behavior? Explain the factors influencing consumer behavior? Factors Influencing Consumer Choice: Consumer choice or decision behaviour refers to t

Auto increment mode and condition code flags, Described auto increment mode...

Described auto increment mode of addressing? Ans: Effective address of the operand is the contents of a register mention in the instruction. After finishing the accessing t

Explain the real time system, What is real time system? A real time sys...

What is real time system? A real time system has well explained, fixed time constraints. Processing must be done within the explained constraints, or the system will fail. It i

A variable number of input arguments, Write a function that will get a vari...

Write a function that will get a variable number of input arguments: the length and width of a rectangle, and possibly also the height of a box that has this rectangle as its base.

Explain about threads model - programming model, Q. Explain about Threads M...

Q. Explain about Threads Model - programming model? In this model a single process can have many as well as concurrent execution paths. The main program is planned to run by na

Characteristics and features of client/server computing, What are the chara...

What are the characteristics and features of Client/Server Computing? Several of client/server computing architecture is listed below: a. It comprises a networked webs of sm

What are dynamic process groups, Q. What are Dynamic Process Groups? To...

Q. What are Dynamic Process Groups? To create and manage dynamic groups a separate library libgpvm3.a should be linked with the user programs which make use of any of group fun

Retina - biometric computer security systems, Retina - Biometric Computer S...

Retina - Biometric Computer Security Systems The next security technology that explained in this report is retina security technology which is very famous in a lot of spy movi

Explain cache organisation, Q. Explain Cache Organisation? Cache memori...

Q. Explain Cache Organisation? Cache memories are found in nearly all latest computers.  They are very helpful for increasing speed of access of information from memory.  Let's

State about dynamic modelling and its inputs, State about Dynamic modelling...

State about Dynamic modelling and its inputs Dynamic modelling is elaborated further by adding concept of time: new attributes are computed, as a function of the attribute chan

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