1. Dr. Clincy Professor of CS
CS Chapter 3 (3A and )
Dr. Clincy
Professor of CS
Finish Ch 3
Introduce Multisim
Dr. Clincy
Lecture
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2. Recall Previous Covered Flip Flops
SR Flip Flop
D Flip Flop
T Flip Flop
JK Flip Flop
Dr. Clincy
Lecture
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3. NOTE Your book doesn’t do a good job in showing you how to derive or design sequential circuits (using state and state assignment tables) – the lecture will do so – please pay close attention to the lecture in understanding how to derive sequential circuits.
Dr. Clincy
Lecture
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4. Combinatorial or Combinational Logic
Recall
Circuit
New Input
Current State or Output
Combinatorial or Combinational Logic
Current State or output of the device is only affected by the current inputs
Examples:
Decoders
Multiplexers
Current State or output of the device is affected by the previous states
Circuit
Flip Flops
New Input
Previous State or Output
Current State or Output
Sequential Logic
Examples:
Shift Registers
Counters
Dr. Clincy
Lecture

5. Sequential Circuit – State Diagram
If x=0, count up,
If x=1, count down
Interested when 2 is realized – z=1 when reach 2, else z=0
If at 0 and x=0, count up to 1 (and z=0)
If at 0 and x=1, count down to 3 (and z=0) x = z 1 S2 S3
State diagram of a mod-4 up/down counter that detects the count of 2. S1 S0
State diagram describes the functional behavior without any reference to implementation
Dr. Clincy
Lecture

6. Sequential Circuit – State Table
Can represent the info in the state diagram in a state table x = z 1 S2 S3
State diagram of a mod-4 up/down counter that detects the count of 2. S1 S0
Dr. Clincy
Lecture

7. Sequential Circuit – Equation
Inputs – y2,y1,x
Outputs –Y2, Y1
Dr. Clincy
Lecture

8. Sequential Circuit – Circuit Design
D Flip Flops used to store values of the two state variables between clock pulses
Output from Flip Flops is the present-state of the variables
Input, D, of the Flip Flops is the next-state of the variables
Dr. Clincy
Lecture

9. Finite State Machine Model
The example we just implemented is an example of a “Finite State Machine” - is a model or abstraction of behavior composed of a finite number of states, transitions between those states, and actions
Dr. Clincy
Lecture

10. Multisim Intro What is Multisim ? Learning Multisim Is SPICE based
An electronic design automation software environment
Provides schematic capture
Provides interactive circuit simulation
Provides circuit analysis tools
Provides integration to a graphical PCB layout environment (Ultiboard) – has a 3D feature
Also provides integration to a system-design and development environment (LabVIEW)
Learning Multisim
Watch Multisim demos and illustrations
Locate Multisim - cseview.kennesaw.edu (access vs install) – look under “N” for “NI Multisim” (National Instruments)
Using Multisim, implement the Full Adder circuit on page 157 using the same chips you used on the breadboard
Work individually
YOU WILL ONLY USE ABOUT 10% OF MULTISIM’S FEATURES

11. Ultiboard – 3D PCB feature