Dr. Clincy Professor of CS CS 3501 - Chapter 3 (3A and 10.2.2) Dr. Clincy Professor of CS Finish Ch 3 Introduce Multisim Dr. Clincy Lecture Slide 1 1

Recall Previous Covered Flip Flops SR Flip Flop D Flip Flop T Flip Flop JK Flip Flop Dr. Clincy Lecture Slide 2 2

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 Slide 3 3

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

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

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

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

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

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

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

Ultiboard – 3D PCB feature