SPLD classification scope: Within the broad PLD landscape (SPLD, CPLD, FPGA), which class specifically covers the smallest, earliest-generation programmable logic devices such as PALs and GALs?
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Aearliest
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Bsmallest
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Clargest
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Dnewest
Answer
Correct Answer: smallest
Explanation
Introduction / Context: Programmable Logic Devices (PLDs) are grouped into classes: SPLD (Simple PLD), CPLD (Complex PLD), and FPGA (Field-Programmable Gate Array). Recognizing what each class includes helps designers choose the right device for logic density, speed, and cost.
Given Data / Assumptions:
- SPLD stands for Simple Programmable Logic Device.
- Examples include PALs (Programmable Array Logic) and GALs (Generic Array Logic).
- Device scale and capability range upward from SPLD → CPLD → FPGA.
Concept / Approach: SPLDs were the earliest widely used PLDs and are also the smallest in logic capacity. They typically provide a programmable AND with fixed OR (PAL) or both AND/OR programmable (PLA variants), and a limited number of macrocells and I/O pins. They are ideal for glue logic and small decoders/encoders.
Step-by-Step Solution:
Identify SPLD definition → Simple devices (PAL/GAL/PLA).Contrast with CPLD/FPGA → much larger resources, routing, and features.Therefore, SPLD class includes the “smallest” devices.Verification / Alternative check:
Textbooks and vendor taxonomies list PAL/GAL under SPLD, confirming their small scale and early adoption.Why Other Options Are Wrong:
earliest: Historically true, but the classification keyword sought is size/capacity, not chronology.largest: Largest belongs to modern FPGAs.newest: Newest devices are advanced CPLDs and FPGAs, not SPLDs.Common Pitfalls:
Equating “earliest” with the answer; the taxonomy is about device scale.Assuming SPLD is a language or software feature rather than a device class.Final Answer:
smallest