More Questions from Programmable Logic Device

Family resemblance: The GAL16V8 architecture is most similar to which earlier programmable logic device family?

Digital Electronics Programmable Logic Device Difficulty: Easy
Choose an option
  • A
    PAL
  • B
    PROM
  • C
    PLD (generic category)
  • D
    SPLD
  • E
    PLA

Answer

Correct Answer: PAL

Explanation

Introduction / Context:GAL (Generic Array Logic) devices were introduced as reprogrammable, pin-compatible upgrades to popular PAL parts. Recognizing this lineage helps when replacing obsolete PALs in legacy designs.

Given Data / Assumptions:

  • Part referenced: GAL16V8.
  • PAL devices used a programmable AND array and fixed OR array.
  • GALs maintain similar macrocell structures but allow reprogramming.

Concept / Approach:The GAL16V8 mirrors the PAL16V8’s I/O architecture and macrocell style, enabling drop-in replacement in many circuits. PROMs and PLAs have different internal organizations (PROM: fixed decoder with programmable outputs; PLA: both arrays programmable).

Step-by-Step Solution:

Identify GAL as a PAL-compatible technology with EEPROM cells.Note pin/function compatibility with popular PAL packages.Conclude the closest match is the PAL family.

Verification / Alternative check:Datasheets list PAL-to-GAL migration guidance, including macrocell modes (combinational/registered) and output enable behavior.

Why Other Options Are Wrong:

  • PROM: Memory-oriented, different internal structure.
  • PLD/SPLD (generic): True categories, but the question asks for the most similar specific family.
  • PLA: Both arrays programmable, unlike PAL/GAL pairing.

Common Pitfalls:Assuming all SPLDs are interchangeable; ignoring pin-compatibility and macrocell mode details when substituting parts.

Final Answer:PAL

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