Demonstration of combinational logic design using Quartus Prime software

Summary

This video explains the design of an automated machine detection and protection system using two types of logical circuit configurations: gate-level and NAND gate configurations. The presentation walks through how basic gates (AND, OR, NOT) are used to produce outputs from given inputs and how to convert these gates into NAND gates using the 'push bubble method.' It also covers waveform simulations to verify the results, explaining the role of don’t care conditions and how they are treated in the logic. The presentation provides a clear overview of the logical circuits, their setup, and the simulation results, helping viewers understand the process of circuit design and simplification.

Takeaways

• 😀 The group presenting the system consists of DJ Easy, Angeline (blue sugar), and Chet (white sugar).
• 😀 The system being presented is an automated machine diagnostic and protection system.
• 😀 Two types of logical circuit configurations are demonstrated: gate-level and N-gate configurations.
• 😀 The gate-level configuration uses basic gates like AND, OR, and NOT gates.
• 😀 The N-gate configuration only uses NOT and AND gates to form the required logic.
• 😀 The system has four inputs, labeled as 'irct', and three outputs labeled as 'A', 'W', and 'M'.
• 😀 To create the gate-level configuration, minimum expressions are derived from a K-map to design the circuits.
• 😀 For output 'A', the minimum expression is derived as A = I' + R' + R + C'.
• 😀 To convert the basic gates to N-gates, a method called the 'pushing bubble method' is used, which involves adding bubbles to gates and combining them accordingly.
• 😀 The waveform simulation results show how the logic levels are represented, with 0 being the bottom and 1 being at the top of the waveform.
• 😀 The simulation takes into account the 'don't care' values in the truth table, treating them as 1s for simplification in expressions, which may lead to simpler logic.

Q & A

What are the two types of logical circuit configurations used in the system?

The two types of logical circuit configurations used in the system are gate-level configurations and NAND gate configurations.

What basic gates are used in the gate-level configuration?

The basic gates used in the gate-level configuration are AND, OR, and NOT gates.

What is the purpose of the minimum expression derived from the K-map?

The minimum expression derived from the K-map is used to simplify and determine how the inputs should be connected to the output gates in the logical circuit.

How do you obtain the value of 'A' in the gate-level configuration?

To obtain the value of 'A', the minimum expression 'A = I' bar OR R bar OR C bar' is used. The inputs are connected to NOT gates to obtain the inverted values and then combined with OR and AND gates.

What method is used to convert basic gates to NAND gates?

The 'pushing bubble method' is used to convert basic gates to NAND gates. This involves adding bubbles on the input side of the gates and then pushing them towards the inputs.

How is the OR gate converted into a NAND gate using the pushing bubble method?

To convert the OR gate into a NAND gate, two bubbles are added to the input side of the OR gate. The bubbles turn the OR gate into an AND gate with inverted inputs, forming a NAND gate.

How is the AND gate converted to a NAND gate?

The AND gate is converted to a NAND gate by adding two AND gates because the bubbles on the inputs represent the inversion, and two inversions cancel each other out.

What is the significance of the 'don't care' conditions in the truth table and K-map?

The 'don't care' conditions in the truth table and K-map are treated as logical ones when simplifying the expressions to create larger loops in the K-map, which helps in deriving the minimal SOP (Sum of Products) expression.

How are 'don't care' conditions treated when writing the SOP expression?

When writing the SOP expression, 'don't care' conditions are treated as logic one, allowing the simplification of the expression to account for larger loops and reducing the complexity of the circuit.

Why is it important to consider 'don't care' conditions in the simulation and simplification process?

Considering 'don't care' conditions in the simulation and simplification process helps in optimizing the circuit by simplifying the expression, which leads to a more efficient and cost-effective design.