Programmable Array Logic | PLA, PROM | STLD | Lec-105

TL;DR

Combinational programmable logic devices help design various logic circuits using reprogrammable technology.

Transcript

hi everyone in this video I'm going to explain about the combinational programable logic devices very very important combinational programmable logic devices combinational programmable logic devices are nothing but we are using programmable logic devices to design combinational logic circuits the meaning of this setting is we are using different ty... Read More

Key Insights

• 🎨 Combinational programmable logic devices are crucial for advanced circuit design and can be adapted to various functionalities.
• 🔬 Programmable Array Logic (PAL) allows for flexibility with programmable AND gates while having fixed OR gates, optimizing for specific design needs.
• ✋ Programmable Logic Array (PLA) provides the highest flexibility, permitting reprogramming of both AND and OR gates, which enhances circuit design adaptability.
• 🔬 Programmable Read-Only Memory (PROM) is characterized by fixed AND gates but allows for programmable OR gates, useful for specific logic applications.
• 😒 The structure of these devices uses arrays to facilitate connections, highlighting the importance of interconnections in programmable logic designs.
• 🤩 An understanding of how to manipulate fuses in these devices is key to effectively utilizing programmable logic technology.
• 🎨 The distinction between fixed and programmable components in CPLDs influences the approach to logic circuit design.

Questions & Answers

Q: What are combinational programmable logic devices used for?

Combinational programmable logic devices (CPLDs) are essential for designing various combinational logic circuits. They allow designers to implement intricate logic functions using programmable technology, facilitating flexibility and adaptability in electronic circuit design. CPLDs can be reprogrammed to adapt to different logic requirements, making them valuable in numerous applications.

Q: Can you explain the three types of programmable logic devices?

The three types of programmable logic devices discussed are Programmable Array Logic (PAL), Programmable Logic Array (PLA), and Programmable Read-Only Memory (PROM). PAL features fixed OR gates with programmable AND gates, PLA has both AND and OR gates programmable, while PROM has fixed AND gates but programmable OR gates. These distinctions affect how each device is used in circuit design.

Q: What is the role of an array in programmable logic devices?

In programmable logic devices, an "array" refers to a structured group of vertical and horizontal interconnections that facilitate logic connections. The arrangement is crucial for programming connections between logic gates. Fuses are used to create or break connections at these intersection points, allowing circuits to be customized during the design process.

Q: How does reprogramming work in programmable logic devices?

Reprogramming in programmable logic devices involves disconnecting and reconnecting fuses used in the programmable array. Once a design is implemented, if changes are needed, the existing connections can be altered by opening specific fuses, thereby allowing the same device to be repurposed for different logic functions without needing physical replacements.

Summary & Key Takeaways

• The content explains the concept of combinational programmable logic devices (CPLDs), focusing on their role in creating combinational logic circuits using programmable logic devices.

• Three main types of CPLDs are discussed: Programmable Array Logic (PAL), Programmable Logic Array (PLA), and Programmable Read-Only Memory (PROM), each with specific programming capabilities and configurations.

• The differences in programmability and functionality among PAL, PLA, and PROM are highlighted, emphasizing how logic gates are either fixed or programmable.