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 is common type system, What is "Common Type System" (CTS)?  CTS e...

What is "Common Type System" (CTS)?  CTS explain all of the basic types that can be used in the .NET Framework and the operations performed on those type. All this time we hav

List the properties which a hashing function should possess, List the prope...

List the properties which a hashing function should possess to ensure a good search performance. What approaches are adopted to handle collision? A hashing function h must poss

Define the time required by sector to reach below read/write, is the time r...

is the time required by a sector to reach below read/write head. Latency Time is the time needed by a sector to reach below read/write head.

Explain definition of fibonacci, Explain definition of fibonacci Where ...

Explain definition of fibonacci Where an input value gives a trivial result, it is returned directly, otherwise the function calls itself, passing a changed version of the inpu

Very long instruction word architecture, Superscalar architecture was desig...

Superscalar architecture was designed to increase the speed of the scalar processor. But it has been realized it's not easy to apply. Subsequent are a number of problems faced in t

Define cloud services with example, Define Cloud services with example. ...

Define Cloud services with example. Any web-based application or service offered by cloud computing is known as a cloud service. Cloud services can contain anything from calend

Explain the test instruction, Explain the TEST instruction TEST instru...

Explain the TEST instruction TEST instruction performs the AND operation. The difference is that AND instruction changes the destination operand whereas TEST instruction doesn

Explain the principles of design, In structure chart whole application is d...

In structure chart whole application is divided into modules (set of program instructions) and modules are designed according to some principles of design. These are: Modularit

What do you mean by segment numbers, Q. What do you mean by Segment numbers...

Q. What do you mean by Segment numbers? There is a good reason for not leaving determination of segment numbers up to assembler. It permits programs written in 8086 assembly

Main problems with evaluation functions, Main problems with evaluation func...

Main problems with evaluation functions: Superlatively, evaluation functions should be quick calculates. Wherever is chance they take a long time to estimate, so after then le

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