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

Write a program that will solve a puzzle, You will write a program that wil...

You will write a program that will solve a version of the common newspaper puzzle \word search." In the puzzle you are given a grid lled with characters and a list of words to nd

How the system would work in real time- simulation, How the system would wo...

How the system would work in real time -  Sensors in/near road gather data (these can be infra-red/light sensors, pressure sensors, induction loops etc.) -data is generally num

Illustrate cache dram, Q. Illustrate Cache DRAM? Cache DRAM (CDRAM) wh...

Q. Illustrate Cache DRAM? Cache DRAM (CDRAM) which is developed by Mitsubishi integrates a tiny SRAM cache (16Kb) on a generic DRAM chip. SRAM on the CDRAM can be used in two

Optimal number of disks , John Lindsay sells disks that have 25 software pa...

John Lindsay sells disks that have 25 software packages that show a variety of financial functions, including net present value, internal rate of return, and other financial progra

Internal organisation of memory chips, expplain in detail the internal orga...

expplain in detail the internal organisation of computer?

What is called checking CRC in cyclic redundancy, In cyclic redundancy chec...

In cyclic redundancy checking CRC is the? Checking CRC, in cyclic redundancy is the remainder. Normal 0 false false false EN-IN X-NONE X-NONE

What is thread, What is Thread? A thread, sometimes termed a lightweigh...

What is Thread? A thread, sometimes termed a lightweight process (LWP), is a fundamental unit of CPU utilization; this comprises a thread ID, a register set, a program counter

Boolean expression derived from this k-map, Let us see the pairs that can b...

Let us see the pairs that can be considered as adjacent in Karnaugh's here. The pairs are:  1)  The four corners  2)  The four 1's as in top and bottom in column 00 & 01

What is meant by the guest function, When  transferring  one  functio...

When  transferring  one  function  to  another,  what  is  meant  by  the  guest  function? A pointer to a function can be passed to another function as an argument. This allows

What is public key cryptography, What is Public Key Cryptography? Pub...

What is Public Key Cryptography? Public-key cryptography is a type of modern cryptography that allows users to communicate safely without any previously agreeing on a shared

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