Net vs line in processor schematics

Question

In this image on Wikipedia https://en.m.wikipedia.org/wiki/File:SPI_three_slaves.svg The connections are called 'lines'.

In a book I'm reading right now, these are called 'nets' in a similar context.

Are there any differences or are they just two terms for the same thing?

score 4 · Answer 1 · answered Dec 17 '20 at 00:24

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Both of these terms are used loosely. You may also hear "signal", "node", or "wire" to refer to the same thing.

answered Dec 17 '20 at 00:24

Elliot Alderson

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I've heard 'signal' as well, which I found pretty weird. Thank you – Daniel Dec 17 '20 at 10:05

score 2 · Answer 2 · answered Dec 17 '20 at 08:50

"Line" is an informal term and it means what it sounds like, a drawing element.

"Net" is an industry de facto standard term. In PCB schematics, the term net means all places in the schematics where that signal occurs. So you could for example have your voltage regulator on page 1 with a "line" going to the V_dd net. On page two of the schematics, the same signal could be used to supply something. All of these occurrences of the same signal forms the net. This net corresponds to traces routed in the PCB layout and you eventually end up with a netlist which is used for the PCB manufacturing process (Gerber files).

score 1 · Answer 3 · answered Dec 17 '20 at 00:31

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A net or line would usually refer to all connections of a signal. A wire or trace is more vague, but often refers to a single point-to-point connection. A net would then be a combination of wires or traces.

answered Dec 17 '20 at 00:31

Mattman944

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score 1 · Answer 4 · answered Dec 17 '20 at 07:08

In the context of schematics:

A 'net', short for 'network', is a collection of interconnected points (pins on ICs, discretes, passives, connectors, etc.)
A 'line' is a drawing element showing a connection between a pair of points in a network.

Schematics can visually represent nets in a number of different ways:

connected by lines pin to pin
connected by junction (dot, tee) between lines
connected by name to the same net
connected as part of a multi-signal bus
connected by off-page ports to other pages (multi-page drawings)
connected by ports to other modules (hierarchical drawings)
automatically connected hidden power/ground - not recommended

The schematic tool scans the drawing and finds these connections and compiles them into a series of lists: each identified net, and the pins each net contains. (The tool will automatically assign a unique net name to each net even if you didn't assign one yourself.)

This list-of-nets information - called, oddly enough, the netlist - is what is used later to make the board layout.

Net vs line in processor schematics

4 Answers4