Task 1

Explain the operation of sequential logic devices

Q1: Illustrate the principles of operation of the following sequential logic devices:

a. D-type flip-flop
b. J-K flip-flop

Describe your answer by providing the combinational logic equivalent circuit of every device, the function (truth) table and the input, output digital waveform and clock.

Q2: Define and illustrate in detail the following operating characteristics of flip-flops and support your answers with illustrations of waveforms of the output and input digital signals:

a. Propagation Delay Time
b. Step-up time
c. Hold time

Support your answers with datasheets.

Task 2

Use formal design techniques to design sequential circuits

Q1: Using a digital clock and three JK flip flops; design a frequency divider digital circuit. Provide the output waveforms whenan 800Hz signal of the output of the clock is applied to the clock input of the 1st flip flop. Describe the operation of the circuit.

Q2: Evaluate the output waveform in relation to the clock for QA, QB and QC in the subsequent circuit and show the binary sequence represented by these waveforms

Discuss the output of the circuit.

Task 3

Construct and test sequential circuits

Build and test theoperation of the sequential circuit inQ2 of task 2. Illustrate the results of your testing with photographs taken during the experiment. Discuss the outcomes of testing the circuit.

Task 4

Use computer simulation to verify logic designs

Using a computer software package, simulate the sequential circuits tested and constructed in task 3. Provide screenshots for the schematic diagram and possible output signals of the circuit. Compare the simulated waveforms with those obtained practically.

Task 5

Design a digital system to meet a technical specification

Design a two-bit digital comparator system that compares two numbers in binary form and prepares a one or a zero at its outputs depending on whether they are the same or not:
• Describe the design steps and the operation of the system.
• Give a block diagram and a circuit diagram of the whole system
• Give the truth table and the output functions of the system.

Task 6

Realise, test and determine the design against criteria

Using a computer software package, simulate the digital system designed in task 5:
1. Provide screenshots for all the possible inputs and outputs of the circuit simulated using the computer software.
2. Test the operation of all gates of the digital system and determine the operation of the system against the design criteria given in task 5.
3. Describe the method of simulation and comment on the simulation results. Show the advantages of using computer simulation.

Task 7

Improve the design by reducing the chip count

Improve the efficiency of the designed digital system of task 6by reducing the amount of logic gates used. You may use Boolean algebra and/or three/four input gates to produce a new system. Using a computer software package, simulate the new system to give similar results to those obtained in task 5.