From SPLD to larger architectures — adding an OR plane enables what device class? By augmenting a simple programmable logic device (SPLD) structure with an OR plane so that both AND and OR arrays are available, you create the foundation for which device type?

Digital Electronics Programmable Logic Device Difficulty: Easy
Choose an option
  • A
    PAL
  • B
    PLA
  • C
    CPLD
  • D
    EEPROM

Answer

Correct Answer: PLA

Explanation

Introduction / Context:SPLDs include device types like PALs and PLAs that implement sum-of-products logic. The key structural difference is whether the AND and OR arrays are programmable or fixed. Understanding this difference helps you map Boolean expressions efficiently to hardware.

Given Data / Assumptions:

  • We begin with a simple PLD structure.
  • We add an OR plane to complement the AND plane.
  • The question asks which device class this enables.

Concept / Approach:A PAL typically has a programmable AND plane and a fixed OR plane; a PLA has both programmable AND and programmable OR planes. Therefore, when you explicitly add an OR plane as a programmable resource (not just fixed) to the basic structure, you are describing a PLA. A CPLD is essentially an array of multiple SPLD-like macrocells with routing; EEPROM is a memory technology, not a logic architecture class.

Step-by-Step Solution:

Identify PAL vs. PLA distinction (fixed vs. programmable OR plane).Adding a programmable OR array → matches PLA characteristics.Therefore, the resulting foundation is a PLA.Select option “PLA.”

Verification / Alternative check:Textbooks show PAL: programmable AND, fixed OR; PLA: programmable AND and OR. CPLD aggregates many macrocells but is a different level of integration.

Why Other Options Are Wrong:

  • PAL: would not require adding a programmable OR plane, since its OR plane is fixed.
  • CPLD: higher-level structure built from multiple SPLD-like blocks.
  • EEPROM: storage technology, not a logic architecture.

Common Pitfalls:Assuming PAL and PLA are interchangeable; the OR-plane programmability is the key differentiator.

Final Answer:PLA

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