computer science

Qseven

Qseven is a computer 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 Qseven rather than just read about it. In short: Qseven, a computer-on-module (COM) form factor, is a small, highly integrated computer module that can be used in a design application much like an integrated circuit component. It is smaller than other computer-on-module standards such as COM Express, ETX or XTX and is limited to very low power consuming CPUs.

Key takeaways

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

Reference excerpt

Qseven, a computer-on-module (COM) form factor, is a small, highly integrated computer module that can be used in a design application much like an integrated circuit component. It is smaller than other computer-on-module standards such as COM Express, ETX or XTX and is limited to very low power consuming CPUs. The maximum power consumption should be no more than 12 watts.

Specification The name comes from the word "quadratic" due to the square shape of the original module, 70 mm on a side. Qseven was specified by Congatec, MSC and SECO in July 2008 as an independent standard for industry-level applications. Other companies based in Europe such as Kontron adopted the standard, but after a few years it had not yet been popular in the USA. The Qseven specification is hosted by the Standardization Group for Embedded Technologies (SGeT), which took over from the original Qseven consortium in 2013. The revision 2.0 was released 9 September 2012, and 2.1 on 25 February 2016. The Qseven design guide provides information for designing a custom system carrier board for Qseven modules. It includes reference schematics for the external circuitry required to implement various peripheral functions. It also explains how to extend the supported buses and how to add additional peripherals and expansion slots to a Qseven-based system. It's available from the Qseven consortium webpage. Since the release of Specification 1.20 (10 September 2010) Qseven modules can be based on x86 or ARM architectures.

Interfaces The Qseven specification defines a rich set of legacy-free interfaces. Older interfaces like PCI, ISA, RS-232 or EIDE are not supported.

4× PCI Express ×1 lanes 2× SATA 8× USB 2.0 1× 1000BaseT Ethernet 1× SDIO 4-bit Low-voltage differential signaling (LVDS) 2× 24-bit SDVO / HDMI / DisplayPort (shared) HDA (High Definition Audio) I²C Bus Low Pin Count bus CAN bus (Controller–area network) Serial Peripheral Interface (SPI) bus

Sizes 70 mm × 70 mm; 70 mm × 40 mm.

Connector Qseven uses one 230 pin MXM2 SMT edge connector to connect all power and signal lanes to the carrier board. This connector is available from multiple vendors at different heights (5.5 mm and 7.8 mm).

See also ETX XTX COM Express Smart Mobility Architecture (SMARC) another specification from the same group

References

External links RTC Magazine: Atom-Based Qseven Module Addresses the Portable Device Market Archived 2011-07-15 at the Wayback Machine

Illustrations

Worked examples

Example 1 — a first encounter with Qseven

Start with the simplest possible case. Write down what Qseven claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer 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 Qseven 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 Qseven 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 Qseven

In research: Qseven appears in computer 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 Qseven 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: Qseven is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer-related introductions in 2008, Computer hardware standards, Motherboard form factors, so understanding it makes those chapters shorter.
In everyday life: Look for Qseven 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 Qseven in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Qseven 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 Qseven out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Qseven in simple terms?

Why does Qseven matter?

Because it connects several computer 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 Qseven?

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 Qseven.