Question 1

Mature logic families and subfamilies Which technology is widely regarded as a mature digital logic family with numerous subfamilies developed over many years of use in industry and education?

Accepted Answer

Introduction / Context: Over decades, digital logic has evolved through several standard families. Some, like TTL, spawned many subfamilies with different speed, power, and drive characteristics. Recognizing these subfamilies aids in reading schematics and choosing compatible parts. Given Data / Assumptions: TTL stands for Transistor-Transistor Logic and includes classic series such as 74, 74LS, 74ALS, 74AS, and 74F. CMOS and ECL also have variants, but TTL is famously taught with a long lineage of pin-compatible subfamilies. “Mature” implies long-standing, extensively documented, and broadly used in legacy designs. Concept / Approach: TTL’s widespread use created many tuned subfamilies balancing speed and power. Low-power Schottky (LS) reduced consumption; Advanced Schottky (AS) and FAST (F) increased speed. This diversity and longevity make TTL a canonical example of a mature technology with many subfamilies. Step-by-Step Solution: List mainstream TTL subfamilies (74, LS, ALS, AS, F).Contrast with CMOS and ECL: while they have variants (HC/HCT for CMOS; PECL, LVPECL for ECL), textbooks traditionally showcase TTL’s breadth of subfamilies.Conclude TTL best fits the description in the question. Verification / Alternative check: Historic logic selection charts show the TTL family tree and electrical characteristics across numerous subfamilies. Why Other Options Are Wrong: CMOS is also mature, but the question points to the classic example extensively subdivided in the 74xx family. ECL has fewer mainstream educational subfamilies compared to TTL. “None of the above” contradicts widely known TTL subfamily lists. Common Pitfalls: Assuming “maturity” equals “most modern.” CMOS dominates modern ICs, but the question emphasizes a long lineage of named subfamilies, which maps best to TTL. Final Answer: TTL

Question 2

FPGA logic implementation style Most modern FPGA logic modules implement arbitrary combinational functions primarily using which architectural approach?

Accepted Answer

Introduction / Context: Modern FPGAs implement arbitrary logic by storing truth tables in small memories inside each logic element. Recognizing this approach helps you reason about how synthesis maps equations and why certain structures, like carry chains, speed up arithmetic. Given Data / Assumptions: Common FPGA families (e.g., Intel/Altera, AMD/Xilinx) use LUT-based logic elements. A LUT is a small memory that outputs a value based on its input address, thereby realizing any function up to the LUT’s input width. Dedicated fast paths (e.g., carry chains) complement LUTs for arithmetic speed. Concept / Approach: A LUT (look-up table) with n inputs stores 2^n entries representing the function’s truth table. By programming these entries, the FPGA can implement any logic function of up to n variables per LUT, and then compose larger functions with multiple LUTs and routing. Step-by-Step Solution: Identify the building block of the FPGA’s logic element: the LUT.Understand that synthesis writes truth tables into LUTs to implement Boolean functions.Recognize that additional resources (e.g., registers, carry chains) optimize sequential behavior and arithmetic.Conclude that “Look-up table” is the primary approach used. Verification / Alternative check: Review any vendor architecture guide; LUT sizes (e.g., 4-input, 6-input) are an advertised parameter and central to device capabilities. Why Other Options Are Wrong: “AND array,” “OR array,” and “AND and OR array” describe classic PAL/CPLD product-term architectures, not mainstream FPGA combinational fabrics. Common Pitfalls: Confusing CPLD product-term macrocells with FPGA LUT fabrics. They achieve similar ends but with different internal structures. Final Answer: Look-up table

Question 3

In FPGA architecture terminology, what is the fundamental logic tile that groups several smaller logic modules together and provides a local, programmable interconnect to connect those internal modules?

Accepted Answer

Introduction / Context: An FPGA is built from repeating tiles of logic plus routing. Vendors give these tiles names, but the common textbook term is a configurable logic block (CLB). This question checks whether you can identify the FPGA building block that clusters smaller logic elements (e.g., LUTs, flip-flops) and includes local programmable interconnect to wire them together efficiently. Given Data / Assumptions: The device in question is an FPGA (field-programmable gate array). The unit contains multiple smaller logic modules (often LUTs and registers). The unit has a local programmable interconnect fabric for intra-tile connectivity. Concept / Approach: Classically, an FPGA organizes logic into CLBs (or similar, such as logic array blocks or configurable logic elements, depending on the vendor). Each CLB contains several LUTs, optional carry chains, flip-flops, and local switch matrices. The local interconnect allows high-speed, short-hop connections without consuming global routing. This is distinct from boundary-scan (JTAG test), bed-of-nails (PCB test fixture), or CPLD (a different class of programmable logic). Step-by-Step Solution: Identify “multiple smaller logic modules” → LUTs/FFs within a tile.Identify “local programmable interconnect” → switch matrix inside the tile.Map to standard term → CLB (Configurable Logic Block).Rule out test and non-FPGA terms (bed-of-nails, boundary scan, CPLD). Verification / Alternative check: Vendor architecture overviews consistently depict CLB/LAB tiles that cluster LUTs and flip-flops and expose local routing resources. Why Other Options Are Wrong: Bed-of-nails is a PCB test method, not a logic block. Boundary scan is a board-level test access standard. A CPLD is a separate device family, not a block inside an FPGA. Common Pitfalls: Confusing vendor-specific names (e.g., slice, LAB) with the generic role of the tile; mixing up board-test terms with internal chip architecture terms. Final Answer: CLB

Question 4

In Altera MAX-series CPLDs using the MAX+PLUS II tool, a macrocell can automatically “borrow” product terms from adjacent macrocells in the same LAB. How many product terms can be borrowed from each of the three adjacent macrocells?

Accepted Answer

Introduction / Context: CPLDs implement sum-of-products logic using product terms. When a single output equation needs more product terms than a single macrocell natively provides, many CPLD families allow “product-term expansion,” borrowing terms from neighboring macrocells inside the same logic array block (LAB). This question probes your understanding of how many product terms can be borrowed per neighbor in MAX+PLUS II flows for MAX-series devices. Given Data / Assumptions: Target: Altera (Intel) MAX family CPLD macrocells. Tool: MAX+PLUS II compiler. Mechanism: product-term borrowing (parallel expanders) from three adjacent macrocells in the same LAB. We must select the correct count per adjacent macrocell. Concept / Approach: Product-term expansion allows a macrocell's OR plane to accept additional product terms sourced from neighboring macrocells via internal expanders. MAX+PLUS II automates this borrowing during fitting, up to a defined limit per neighbor, thus enabling larger SOP equations without external device resources. Step-by-Step Solution: Recognize that each macrocell supports a base number of product terms.When more are needed, the fitter checks adjacent macrocells for available terms.The automatic limit enforced by the tool per neighbor in the same LAB is 5 product terms.Therefore, with three neighbors, up to 15 additional terms can be aggregated (subject to availability). Verification / Alternative check: Device handbooks and tool user guides describe “parallel expanders” that provide a fixed number of additional terms per adjacent macrocell. Historical training materials commonly cite 5 per neighbor for these devices. Why Other Options Are Wrong: 4/6/7 do not match the standard per-neighbor borrowing limit documented for these flows; choosing them would over- or under-state the actual tool constraint. Common Pitfalls: Confusing total borrowable terms with per-neighbor limits; assuming borrowing works across LAB boundaries (it does not—limited to the same LAB). Final Answer: 5

Question 5

Within a programmable-logic development software suite, what is the application that orchestrates synthesis/fitting steps and generally controls the overall operation of the toolchain called?

Accepted Answer

Introduction / Context: Programmable-logic design software bundles multiple steps: design entry, elaboration, synthesis, fitting/place-and-route, and programming file generation. The coordination of these steps is handled by a central application. This item asks you to name that controlling application. Given Data / Assumptions: The environment is a PLD/FPGA tool suite. One application “controls the operation of the software.” We are to identify the correct term among the options. Concept / Approach: In vendor flows, the “compiler” is the umbrella application that invokes synthesis, optimization, technology mapping, and fitting to produce a device-ready programming file. Other terms in the options are unrelated: bed-of-nails is a PCB test fixture; boundary scan is a JTAG test methodology; primitive refers to a basic library element (gate, LUT, flip-flop) inside the device. Step-by-Step Solution: Map “controls the operation of the software” to the orchestrator of build steps.In PLD/FPGA workflows, this orchestrator is called the compiler.Rule out test and library terms not responsible for flow control. Verification / Alternative check: Tool GUIs and command-line interfaces frequently label the top-level action as “Compile,” which triggers synthesis and fitter passes. Why Other Options Are Wrong: Bed-of-nails and boundary scan relate to testing hardware, not running the software toolchain. Primitive is a device building block, not a controller application. Common Pitfalls: Confusing “synthesis” (a specific step) with the entire flow controller; many vendors still call the flow orchestrator the compiler even when third-party synthesis tools are integrated. Final Answer: compiler

Question 6

Which device can realize any Boolean function of the input variables by effectively generating every possible AND (minterm) product term and then selecting among them?

Accepted Answer

Introduction / Context: Digital designers often compare classic programmable devices by how their internal arrays are organized. The ability to realize any Boolean function directly depends on whether the device can make all minterms (AND products) available for selection. Given Data / Assumptions: We want a device that generates every possible AND product term of the inputs. Then it produces the desired function by OR-ing selected terms. Options include GAL, SOP, PROM, and LAB. Concept / Approach: A PROM uses a full decoder that generates all 2^n minterms of the n inputs, effectively creating every possible AND term. The memory array then stores desired output bits for each minterm; reading the addressed word is equivalent to forming an OR of the selected minterms. Thus a PROM can implement any combinational truth table directly. A GAL is a small SPLD with limited product terms; SOP is a form, not a device; LAB is a cluster inside some FPGAs/CPLDs, not a standalone device class. Step-by-Step Solution: Recognize that a full decoder + ROM can represent any truth table.PROM architecture provides all minterms via address decoding.Therefore, PROM fits the requirement of “generates every possible AND term.” Verification / Alternative check: Textbooks routinely state that a ROM/PROM is a universal combinational device because it stores the output for every input combination. Why Other Options Are Wrong: GAL has limited product terms per output. SOP is not hardware. LAB is a sub-block and does not inherently generate all minterms on its own. Common Pitfalls: Confusing logical forms (SOP) with hardware implementations; assuming any PLD always has “all minterms” available (only PROM/PLA style guarantees this). Final Answer: PROM

Question 7

In the Altera MAX7000S family, identify the two major on-chip structures that define logic clustering and interconnection resources.

Accepted Answer

Introduction / Context: MAX-class CPLDs group macrocells into logic array blocks (LABs) and connect those LABs using a global interconnect. Knowing these architectural terms helps you reason about placement, timing, and resource usage. Given Data / Assumptions: Target family: MAX7000S. We must pick the two key structures that represent logic clusters and the chip-wide interconnect fabric. Concept / Approach: In MAX7000S, macrocells are organized into LABs. LABs connect to each other and to I/O via the Programmable Interconnect Array (PIA). While LUTs dominate FPGA fabrics, CPLDs use product-term macrocells; thus “LUT” is not the primary resource in this CPLD family. FMUX is a vendor-specific multiplexer feature elsewhere; it is not a top-level architectural pair for MAX7000S. Step-by-Step Solution: Identify logic clustering → LAB.Identify global/inter-LAB routing → PIA.Select LAB and PIA as the two major structures. Verification / Alternative check: Family block diagrams label macrocells grouped into LABs with a PIA providing routing. Why Other Options Are Wrong: LUTs characterize FPGAs more than MAX CPLDs. FMUX is not the defining chip-level interconnect for MAX7000S. Pairings with LUTs therefore mischaracterize the architecture. Common Pitfalls: Assuming all programmable logic uses LUTs; overlooking that CPLDs implement sum-of-products macrocells instead. Final Answer: LAB, PIA

Question 8

In programmable-logic projects, what is the name for the complete sequence of steps—from design entry through fitting and programming—that ultimately produces a configured target device?

Accepted Answer

Introduction / Context: Engineering teams follow a structured sequence when building programmable-logic designs. From writing HDL or drawing schematics, through simulation, synthesis, fitting, timing analysis, and generating a programming file, the entire series of steps has a standard name. Given Data / Assumptions: The question asks for the overarching process name, not a single step. The goal is a fully programmed target device. Concept / Approach: “Design flow” is the accepted term for the end-to-end methodology. Graphic entry is one possible design input method. Downloading is a late step that transfers a programming file to hardware. LAB is an architectural block, not a process. Step-by-Step Solution: List major steps: entry → simulate → synthesize → fit → timing → program.Recognize the umbrella term for the sequence is “design flow.”Discard terms that refer to single steps or unrelated structures. Verification / Alternative check: Vendor documentation and EDA textbooks universally use “design flow” for the complete process. Why Other Options Are Wrong: Graphic entry is one modality. Downloading is one late step. LAB is unrelated to process. Common Pitfalls: Equating the programming step with the whole flow; ignoring earlier verification steps that are crucial for first-time-right designs. Final Answer: design flow

Question 9

With respect to ASIC design styles, full-custom integrated circuits can typically achieve which combination of performance and silicon area?

Accepted Answer

Introduction / Context: ASIC methodologies range from standard-cell and gate-array to full-custom. Full-custom gives designers fine-grained control over transistors, layout, and interconnect to maximize performance, but it carries cost/area trade-offs. Given Data / Assumptions: We compare speed (performance) and die area (resource usage). Full-custom implies manual, transistor-level layout optimization. Concept / Approach: Full-custom chips achieve the highest speed by tailoring device sizes, routing paths, and analog-aware geometries. However, such bespoke layout typically consumes more engineering effort and silicon area relative to automated flows. Thus the realistic pairing is “highest speed, largest die area.” Competing answers that claim both highest speed and smallest area ignore practical overheads and design margining common in full-custom practice. Step-by-Step Solution: Identify the design style → full-custom (hand-optimized).Relate optimization to speed → highest potential performance.Relate layout practices to area → usually larger area due to custom devices, guard rings, tailored routing. Verification / Alternative check: VLSI design texts note that while standard-cell emphasizes density and productivity, full-custom prioritizes performance (and sometimes analog behavior), often at increased area and cost. Why Other Options Are Wrong: “Lowest speed” options contradict the purpose of full-custom. “Highest speed, smallest die area” is overly optimistic and atypical for broad digital designs. Common Pitfalls: Assuming optimization automatically reduces area; in reality, sizing devices for speed, adding shielding, and using non-minimum geometries tends to increase area. Final Answer: highest speed, largest die area

Question 10

Classify the Boolean form of the expression AB + CD in terms of canonical implementation styles used in programmable logic.

Accepted Answer

Introduction / Context: Two common canonical Boolean forms are sum-of-products (SOP) and product-of-sums (POS). Recognizing which form a given expression belongs to helps you map it to specific hardware resources in PLDs and CPLDs. Given Data / Assumptions: Expression: AB + CD. We need to categorize it by canonical form, not by device type. Concept / Approach: In SOP, multiple product terms (ANDs of literals) are ORed together. In POS, multiple sum terms (ORs of literals) are ANDed together. AB and CD are products (ANDs). Joining them with + indicates a sum (OR) of those products. Therefore, AB + CD is SOP. Step-by-Step Solution: Identify each term: AB (A*B) is a product; CD (C*D) is a product.Combine via + → OR of product terms.Conclude: AB + CD is a sum-of-products (SOP). Verification / Alternative check: Truth-table or Karnaugh-map implementations naturally produce SOP minimizations where each implicant corresponds to a product term ORed together. Why Other Options Are Wrong: PAL and GAL are device types, not Boolean forms. POS would look like (A + B)(C + D), not AB + CD. Common Pitfalls: Confusing hardware acronyms with algebraic forms; forgetting that the + symbol represents OR while adjacency represents AND. Final Answer: SOP

Question 11

Identify the best classification for the Altera EPM7128S device with respect to programmability and in-system configuration capability.

Accepted Answer

Introduction / Context: The EPM7128S is a well-known member of the MAX7000S CPLD family. Recognizing how it is programmed and whether it supports in-system programmability (ISP) helps with board design, firmware updates, and manufacturing test flows. Given Data / Assumptions: Device: EPM7128S (MAX7000S family). We must select the most appropriate classification regarding programming capability. Concept / Approach: MAX7000S devices support ISP via a JTAG interface, allowing the CPLD to be programmed after soldering on the PCB. While “PLD” is generically true, it does not express the key capability asked. “EEPROM” describes internal non-volatile storage technology but not the user-visible programming feature. “JTAG” is the interface/protocol but not the capability classification. The most accurate and focused descriptor is “ISP.” Step-by-Step Solution: Note that MAX7000S supports JTAG-based in-system programming.Select “ISP” as the capability classification.Reject broader or less specific terms that miss the capability emphasis. Verification / Alternative check: Datasheets and user guides highlight ISP features for EPM7128S (programming and re-programming through JTAG pins on the assembled board). Why Other Options Are Wrong: “PLD” is too general; “EEPROM” focuses on storage technology, not capability; “JTAG” is the transport, not the capability classification. Common Pitfalls: Equating the presence of JTAG with boundary-scan only; overlooking that JTAG also enables ISP of the device’s configuration. Final Answer: ISP

Question 12

Among standard logic device families used today, which technology is the most widely adopted for general-purpose digital ICs?

Accepted Answer

Introduction / Context: Standard logic families have evolved as semiconductor processes advanced. Performance, power consumption, and integration density determine which family dominates mainstream use. This question asks you to identify today’s most popular family. Given Data / Assumptions: We consider widespread, general-purpose digital IC usage. Options include TTL, CMOS, and ECL families. Concept / Approach: Complementary metal-oxide semiconductor (CMOS) technology offers very low static power, high integration density, scaling with modern processes, and broad voltage range support. As a result, CMOS underpins the vast majority of digital ICs, from microcontrollers to FPGAs and ASICs. TTL, though historically important, consumes more static power and is largely confined to legacy/compatible parts. ECL provides very high speed but at a significant power cost, limiting it to niche applications. Step-by-Step Solution: Compare families on power, speed, and density.Recognize that CMOS best balances these for mass production and low power.Select CMOS as the most popular standard logic family. Verification / Alternative check: IC market data and vendor portfolios show CMOS domination across consumer, industrial, and embedded markets. Why Other Options Are Wrong: TTL is older and power-hungry; ECL is fast but power-intensive and niche; “None of the above” contradicts market reality. Common Pitfalls: Equating high speed with popularity; overlooking cost and power, which drive volume adoption. Final Answer: CMOS

Question 13

MAX7000S CPLD resource usage: When a general-purpose I/O pin is configured as an input (no external output drive), the associated macrocell is freed. In this configuration, that macrocell can be reassigned and used internally for what purpose within…

Accepted Answer

Introduction / Context: In Complex Programmable Logic Devices (CPLDs) such as the MAX7000S family, each user pin typically connects to an Output Logic Macrocell (OLMC). Designers often ask what happens to that macrocell when the corresponding pin is configured strictly as an input. Understanding this frees up valuable on-chip resources and enables more efficient logic packing. Given Data / Assumptions: Target device family: MAX7000S class CPLD. A specific I/O pin is configured as an input-only pad. Each I/O pin normally pairs with an OLMC (macrocell) that can drive the pin or be fed back internally. The question: how the macrocell can be repurposed when the pin is input-only. Concept / Approach: A macrocell can be used either to drive an external pin or for internal (buried) logic. If the pin is set as input-only, the output driver is disabled, allowing the OLMC to be used internally without consuming an additional external pin. This is commonly described as using the macrocell as “buried logic.” Step-by-Step Solution: Identify OLMC roles → can implement sum-of-products logic and optionally a register.Configure pin as input → disables external drive; the OLMC is no longer obligated to feed an output buffer.Freed OLMC → can be allocated for additional equations/registers inside the device (buried).Therefore, the correct reuse is “buried logic.” Verification / Alternative check: Vendor handbooks and fitter reports typically label such macrocells as “buried” when not bonded to outputs. Why Other Options Are Wrong: another output: Not possible because the pin is configured as input-only; no external drive is used.extra speed: Speed is a timing characteristic, not a functional repurpose of the macrocell.in-system testing: Boundary scan or JTAG are separate features; this is not the macrocell’s repurpose. Common Pitfalls: Assuming each macrocell must always drive a pin; in CPLDs, macrocells can be internal.Confusing input buffer configuration with macrocell availability. Final Answer: buried logic

Question 14

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?

Accepted Answer

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

Question 15

ASIC design categories overview: Four mainstream subcategories often cited for creating digital systems are PLDs, gate arrays, standard cells, and which additional category of customization?

Accepted Answer

Introduction / Context: Application-Specific Integrated Circuits (ASICs) encompass multiple implementation styles. Understanding the four classic categories helps engineers weigh NRE cost, performance, time-to-market, and unit cost. Given Data / Assumptions: Common categories include PLDs (programmable logic devices), gate arrays (semi-custom with prefabricated transistors), and standard cells (cell libraries placed and routed). A fourth category reflects maximum customization at the transistor/layout level. Terminology focuses on implementation style rather than vendor-specific branding. Concept / Approach: The missing category is “full custom,” where every transistor and interconnect can be hand-crafted for optimal speed, power, and area. This approach has the highest NRE and longest development cycle but enables peak performance and density. Step-by-Step Solution: List known three → PLDs, gate arrays, standard cells.Identify the top-customization category → full custom ASIC.Therefore, the fourth category is “full custom.” Verification / Alternative check: ASIC design textbooks consistently present these four tracks. Why Other Options Are Wrong: HCPLDs: Not a standard ASIC category; CPLD is a PLD subclass, not separate in this quartet.GAL: A specific SPLD type, not an ASIC category.FPLDs: General term for programmable logic (e.g., FPGA/CPLD) already covered under PLDs. Common Pitfalls: Confusing device families (e.g., GAL) with implementation categories.Thinking gate arrays include full-custom; they do not—they are semi-custom. Final Answer: full custom

Question 16

Altera FLEX10K family architecture: Identify the dominant logic implementation style used by FLEX10K devices for mapping combinational functions.

Accepted Answer

Introduction / Context: The Altera (Intel) FLEX10K family is a classic FPGA architecture predating modern Stratix/Arria/Cyclone lines. A key point for designers is recognizing whether the fabric is PLA-like (programmable arrays) or LUT-based, because this affects how logic maps and how timing behaves. Given Data / Assumptions: FLEX10K is an FPGA family with configurable logic blocks interconnected by routing resources. FPGA logic is commonly implemented using look-up tables (LUTs) that store truth tables. PAL/PLA-like AND/OR arrays are associated with SPLD/PLA devices rather than mainstream FPGAs. Concept / Approach: LUTs implement boolean functions by addressing small SRAM tables with input bits and reading the stored output bit. This method scales and supports logic optimization by synthesis tools. FLEX10K maps user logic into LUT-based logic elements (LEs) grouped into larger blocks with local interconnects. Step-by-Step Solution: Recognize FLEX10K as an FPGA → typical for LUT logic elements.Note that AND/OR arrays characterize PAL/PLA, not FLEX10K.Therefore, the correct architecture descriptor is “look-up table.” Verification / Alternative check: Vendor architecture guides describe LEs based on LUTs plus optional flip-flops and carry chains. Why Other Options Are Wrong: OR array: Incomplete and not the FLEX10K approach.AND array: Also incomplete; not representative of FLEX10K.OR and AND array: Describes PLA/FPLA, not FLEX10K. Common Pitfalls: Confusing SPLD/PLA terminology with FPGA fabrics.Assuming all programmable logic uses AND/OR planes; most FPGAs use LUTs. Final Answer: look-up table

Programmable Logic Device Questions