GAL devices and reprogrammability: Generic Array Logic (GAL) chips use an EEPROM-based array that is erasable and can be reprogrammed many times (for example, at least 1000 program/erase cycles). Does this characterization hold?

Difficulty: Easy

Correct Answer: Correct

Explanation:


Introduction / Context:
GAL (Generic Array Logic) devices were introduced as flexible, pin-compatible replacements for one-time programmable PALs. Their key advantage is reprogrammability, enabled by EEPROM technology, which supports many erase/write cycles and simplifies prototyping and field updates.



Given Data / Assumptions:

  • GALs store configuration in EEPROM cells.
  • EEPROM supports multiple erase/write cycles (often 1000+).
  • No UV window is required; erasure is electrical.


Concept / Approach:
Unlike fuse-based PALs (one-time programmable) and UV-erasable EPROMs, GALs allow electrical reprogramming. This means designers can iterate the logic design repeatedly without replacing the chip. The reprogrammability threshold (for example, 1000 cycles) is typical for early-generation EEPROM processes and is sufficient for development and moderate maintenance cycles.



Step-by-Step Solution:

Confirm memory type: GAL = EEPROM-based configuration.Check endurance: EEPROM endurance commonly ranges from 10^3 to 10^5 cycles depending on process.Implication: device can be re-used across many design iterations.Conclusion: the statement is accurate for standard GAL parts.


Verification / Alternative check:
Datasheets for GAL16V8/GAL22V10 families list EEPROM-based configuration and typical endurance specs, confirming erasability and reprogram capability well beyond a single cycle.



Why Other Options Are Wrong:

Incorrect: Conflicts with the fundamental EEPROM-based nature of GALs.Applies only to PROM-based GALs: GALs are not PROM-based; PROMs are one-time programmable.Only true for UV-erasable versions: GALs are electrically erasable; no UV window or lamp is needed.


Common Pitfalls:
Confusing GALs with classic PALs; assuming UV erasure like EPROMs; ignoring endurance limits when planning frequent in-field updates.


Final Answer:
Correct

More Questions from Programmable Logic Device

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion