[B3D News]

TSMC unveiled their 40nm process yesterday, and seem to have confused a bunch of people in the process. So let's try to quickly set the record straight and see how this ties in with our earlier reports on TSMC's roadmap.

Read the full news item

[Time]

Maybe a stupid question but what's a half node (also referred to as an optical shrink)?

[silent_guy]

Originally Posted by Time

Maybe a stupid question but what's a half node (also referred to as an optical shrink)?

It's a technology process that retains enough (almost all) characteristics of its parent node, so that you can use the same libraries, wire load models, etc., but that is smaller in size than the parent node. Since most of the characteristics are the same, a fab can roll out half-nodes much quicker than full nodes.

Basically, you design, synthesize and do the place and route of the chip as if you're designing for the parent node, deliver the layout to the fab, which then optically reduces the layout to the smaller half node. Half nodes are usually slightly faster, since signal travelling distances are a bit shorter, but electrically, the transistors are usually hardly if any faster than the parent node.

It's usually not possible to take an original, working, major node design and shrink it to its half node: analog cells often behave differently and certain digital characteristics may change enough to make them non-functional (slightly faster operation may result in hold time violations.) For analog cells, a common practice is to take the full node design, increase its size with the same amount it will be shrunk later on. The end result is an analog cell that's as big in the half node as it is in the full node and that behaves pretty much identical.

[Time]

Thank you, a perfect answer. (sorry for sounding like I'm scoring you)

[Berek]

This should be an excellent step to the small form factor market; phones, MP3 players, and other handheld type of devices.

It's interesting that they are skipping 45 GP? ATI and Nvidia are "almost" doing that with their video card series, although its a bit different in that they are essentially recycling the same technology into their current product lines, with the new "55nm" architectures coming out this summer.

I'd like to see the power requirements of these... too bad this article didn't state any numbers this time around.

[Arun]

Originally Posted by Berek-Halfhand

This should be an excellent step to the small form factor market; phones, MP3 players, and other handheld type of devices.

Just making sure, you mean *for* the small form factor market, right? Since obviously process technology alone won't magically transform a design into something you can sell into handhelds.

It's interesting that they are skipping 45 GP? ATI and Nvidia are "almost" doing that with their video card series, although its a bit different in that they are essentially recycling the same technology into their current product lines, with the new "55nm" architectures coming out this summer.

I'm not sure what TSMC's process technology has to do with recycling GPU architectures - am I missing something here?

I'd like to see the power requirements of these... too bad this article didn't state any numbers this time around.

Yeah well if it's not supplied I can't make up numbers just to make people happy sadly!

[Berek]

Yes, you would be correct, sorry I forgot to add that word in there .

As for the architectures, I'm just pointing out the parallels, not the similarities in technology itself.