science

GAL22V10

GAL22V10 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand GAL22V10 rather than just read about it. In short: The GAL22V10 is a series of programmable-logic devices from Lattice Semiconductor, implemented as CMOS-based generic array logic ICs, and available in dual inline packages or plastic leaded chip carriers. It is an example of a standard production GAL (General Array Logic) device that is often used in educational settings as a basic programmable-logic device.

Key takeaways

GAL22V10 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect GAL22V10 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GAL22V10 from memory before moving on to harder problems.

Reference excerpt

The GAL22V10 is a series of programmable-logic devices from Lattice Semiconductor, implemented as CMOS-based generic array logic ICs, and available in dual inline packages or plastic leaded chip carriers. It is an example of a standard production GAL (General Array Logic) device that is often used in educational settings as a basic programmable-logic device. In combinatorial mode, it is conceptually a group of programmable AND-OR-invert (AOI) (AND-NOR) gates or AND-OR gates.

Specifications

The GAL22V10 has 12 input pins, and 10 pins that can be configured as either inputs or outputs, and exists in various switching speeds, from 25 to 4 ns. Each output is driven by an output-logic macrocell (OLMC), with an output-enable product term, and a variable number of product terms, ranging from eight to sixteen. Each OLMC may be set to output as inverting or non-inverting, and be placed into either registered or combinatorial mode. In registered mode, each macrocell actively uses a D-flip-flop to hold a state under control of the data input from the logic portion of the macrocell and the rising edge of the clock signal, while in combinatorial mode the flip-flop is removed from the macrocell and the outputs are driven directly by the logic. In the latter mode, the pin may also dynamically switch between input and output based on the product term. In either mode the pin value is fed back into the array as a product term. Combinations are set using an E2PROM. The output registers can be preloaded into a potentially invalid state for testing by a GAL22V10 programmer. Inputs and outputs include active pull-ups and are transistor-transistor logic compatible due to high-impedance buffers. A user electronic signature section is included for details such as user ID codes, revision IDs, or asset tagging on official Lattice Semiconductor units, as well as a static ES section for compatibility with non-Lattice Semiconductor GAL22V10 units. In addition, a security cell is included which, when set, disallows the retrieval of the array logic from the chip, until a new set of logic is set. Latch-up protection is implemented using n-pullups and a charge pump in the official Lattice Semiconductor models.

Availability The GAL22V10D had been discontinued by Lattice Semiconductor as of June 2010 with the last shipment in June 2011. No pin-compatible replacements have been offered or recommended by Lattice. Multiple variations of the Microchip / Atmel ATF22V10 are pin-compatible replacements, and available in PDIP, SOIC, PLCC, TSSOP packages.

Related parts

The GAL16V8 and GAL20V8 are similar in concept to the GAL22V10, but have fewer I/O pins in smaller packages.

References

Further reading Historical books Programmable Logic Designer's Guide; Roger Alford; Sams Publishing; 1989; ISBN 0-672-22575-1. (archive) PAL Programmable Logic Handbook; 4ed; Monolithic Memories; 407 pages; 1985. (archive) PEEL Software and Applications Handbook; International CMOS Technology (ICT); 138 pages; 1989. (archive) (also, see design guide sections of databooks below) Historical Lattice documents Introduction to GAL Device Architectures; 15 pages; 1998. Lattice GAL22V10 datasheet; 29 pages; 1998. Lattice GAL16V8 datasheet; 22 pages; 2001. Historical AMD documents AMD PALCE16V8H Datasheet and Design Guide; 61 pages; 1989. AMD PAL Databook and Design Guide; 764 pages; 1993. Historical National documents National Programmable Logic Devices Databook and Design Guide; 502 pages; 1990. Microchip/Atmel documents (modern lower-power parts that are still being manufactured) Microchip ATF22V10B, ATF22V10C, ATF22V10CQ, ATF22V10CQZ datasheets. Microchip ATF16V8B, ATF16V8BQL, ATF16V8C, ATF16V8CZ datasheets.

External links GALasm - open-source GAL assembler. Galette - open-source GAL assembler. Afterburner - open-source GAL hardware programmer.

Illustrations

Worked examples

Example 1 — a first encounter with GAL22V10

Start with the simplest possible case. Write down what GAL22V10 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to GAL22V10 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about GAL22V10 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of GAL22V10

In research: GAL22V10 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses GAL22V10 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: GAL22V10 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Field-programmable gate arrays, so understanding it makes those chapters shorter.
In everyday life: Look for GAL22V10 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study GAL22V10 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GAL22V10 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain GAL22V10 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GAL22V10 in simple terms?

Why does GAL22V10 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study GAL22V10?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on GAL22V10.