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

Explain the data dependency, Data Dependency It indicates to the situ...

Data Dependency It indicates to the situation in which two or more instructions share same data. The instructions in a program are able to be arranged based on relationship o

Classification of interrupts - computer architecture, Classification of int...

Classification of interrupts:   1. a) asynchronous   external components or hardware malfunction 1.b)synchronous   function of program state (for example over

Define about pascaline - mechanical computers, Pascaline:Mechanical compute...

Pascaline:Mechanical computers Blaise Pascal made the initial attempt in the direction of this automatic computing. He invented a apparatus, which comprised of lots of gears an

Write a linux terminal shell, Write a Linux terminal shell. Your shell shou...

Write a Linux terminal shell. Your shell should act similar to bash. At a high level, your shell should accomplish the following: 1. Print a prompt when waiting for input from t

Operating systems, Consider the state transition diagram of Figure 3.9b . S...

Consider the state transition diagram of Figure 3.9b . Suppose that it is time for the OS to dispatch a process and that there are processes in both the Ready state and the Ready/S

Explain creating files for writing only in c, Creating Files for Writing On...

Creating Files for Writing Only Creating Files for Writing Only : To create a text file for writing only, pass "w" into fopen as the second argument. This example follows along

Can a vector have a component equivalent to zero, Q. Can a vector have a co...

Q. Can a vector have a component equivalent to zero and still have a nonzero magnitude? Answer:- Yes For example the 2-dimensional vector (1, 0) has length sqrt (1+0) = 1

Last ant on rod, i want program code for the above question in c language

i want program code for the above question in c language

Describe the concept of value creation, I am required to write about the im...

I am required to write about the impact of the internet on firms with reference to the following questions: 1. Describe the concept of value creation. Explain how a firm can use

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