Flip-flop and Finite State Machine

1 / 16

# Flip-flop and Finite State Machine - PowerPoint PPT Presentation

Flip-flop and Finite State Machine. By: Radha Iyer Prof: Dr. Sin-Min Lee CS147 Computer Organization and Architecture. What is Sequential Circuits?. A Sequential Circuit can be defined as circuit having sequential logic. Sequential logic is a type

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Flip-flop and Finite State Machine' - dulcinea

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Flip-flop and Finite State Machine

By:

Prof: Dr. Sin-Min Lee

CS147 Computer Organization and Architecture

What is Sequential Circuits?
• A Sequential Circuit can be defined as circuit

having sequential logic. Sequential logic is a type

of a logic circuit whose output depends not only on

current inputs but also on previous inputs.

What are flip-flops?
• In order to remember previous inputs, sequential circuits must have some sort of storage element. This storage element is called “flip-flop”.
• Flip-flop depends on previous inputs to the circuit.
• The basic memory unit is called an SR flip-flop.
• We can describe flip-flops using characteristic table.
Unstable Circuit
• S-stands for set
• R- stands for re-set
• If both S and R are set to1 in the SR flip-flop at the same time then it resulted in an unstable circuit, so this combination is not allowed.
• To take care of this problem JK flip-flops were developed.
What is JK flip-flop?
• It is a variation to SR flip-flop, but it takes care of the S=R=1 combination.
• (J=Set, K=Reset)
• When it comes to the S=R=1 it toggles. It is a great improvement over the SR flip-flops.
What are D flip-flops?
• Another modified version of SR flip-flops are D flip-flops.
• ‘D’ stands for data flip-flops.
• It represents physical computer memory.
• The output always takes on the state of the D input at the rising clock edge.
• D flip-flops are very useful as they capture the signal when the clock rises.
• Flip-flops are very useful and are found in a lot of electronic devices.
Finite State Machine
• It is a model of behavior composed of a finite number of states, transitions between those states, and actions, (wikipedia,2000).
• A finite state machine is an abstract model of a machine with a primitive internal memory.
• It depicts the graphical part of the flip-flops.
Moore/Mealy Machine’s
• Moore machine represents the JK flip-flops
• Output depends only on the state.
• Example for the Moore machine model will be the elevator door, which just open’s and closes
• Mealy Machine depends on output and state.
• Example of Mealy Machine will be Microwave oven.
Conclusion
• We learned about flip-flops which are basic storage elements.
• There were different kinds of flip-flops versions developed SR, JK, D flip-flops.
• Then we learned about Finite State Machines which are primitive internal memory.
• We saw Moore Machine, Mealy Machine which are types of Finite State machines.
Sources
• http://en.wikipedia.org/wiki/Flip-flop_(electronics)
• http://en.wikipedia.org/wiki/Finite-state_machine