How hard is it to migrate a design from 40nm to 28nm? Can this be automated?
Yes, much more than from 28 to 22 or 16. 40nm+ are planar transistors, and below are FinFETs
TSMC to customers: It's time to stop using older nodes and move to 28nm
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Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#32Earlier quoted context omitted.
Depends on the design. Did you throw RTL at a layout engine and let it figure it out? Pretty damn close to automated and could get to automated with a little upfront elbow grease by a company specializing in such things. Heavy analog design? It's going to be a lot more work.
Maybe my intuition is completely wrong here, but would the analog case be simplified if the target node+technology was chosen to have trace widths exactly 1/2 the size of the node being transitioned from? I.e. the traces would have essentially the same standing-wave tuning requirements when modelled as waveguides; would catch a harmonic of the original frequency when acting as antennae; etc.
Analog isn't just RF; PHYs for weird protocols is a giant component of the space, as well as power monitoring/management. The changes in how voltage/resistance/capacitance/etc work at each node for a given layout is the heavy lift.
Additionally, you very, very rarely have the antenna on chip, and the analog bits even for RF are more signal conditioning that isn't typically modeled like waveguides, but instead more like those old analog plug board computers, simply integrated onto a chip.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#33Thanks TSMC... when will you release a HV version of 28nm? Oh... never, because you transitioned to bottom poly at 40nm. How is your automotive eFlash at 28nm... oh, you're still working on it (since 2018)? Well, guess we won't have many display drivers (or displays) or autos then, or maybe marketing should pull their heads out and smell the roses. I mean, I get it. Most things should transition to 28nm on 300mm wafe…
I honestly don't really understand 95% of what you've written here, but could this mean an end of godawful touch screens in cars?
No, it means there will be even worse touchscreens because now automakers can't afford silicon that might actually power a tablet.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#34Thanks TSMC... when will you release a HV version of 28nm? Oh... never, because you transitioned to bottom poly at 40nm. How is your automotive eFlash at 28nm... oh, you're still working on it (since 2018)? Well, guess we won't have many display drivers (or displays) or autos then, or maybe marketing should pull their heads out and smell the roses. I mean, I get it. Most things should transition to 28nm on 300mm wafe…
Seems like the automotive industry is gonna be the one to have to blink here. I’m not intimately involved in the details of the industry but didn’t the automotive industry already try to pass their risk onto TSMC by cancelling contracts early on into covid and we’re already told to get to the back of the line when they wanted their chip orders again? If TSMC has enough demand to sell everything they make, they don’t…
Legacy auto is screwed. They are getting smaller and have fixed costs and fixed cultures that are going to be hard to remove. At the same time this makes it hard to recruit the types of people you need to turn the ship around.
This thread is a good example of the legacy auto mentality of blaming a supplier, instead of taking responsibility for the situation they are in.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#35Earlier quoted context omitted.
Depends on the design. Did you throw RTL at a layout engine and let it figure it out? Pretty damn close to automated and could get to automated with a little upfront elbow grease by a company specializing in such things. Heavy analog design? It's going to be a lot more work.
How common are those two classes?
You'd have to ask a fab probably to get real numbers, but the chips that people care about that haven't migrated to a newer node trend towards having at least some mixed analog components more than the set of all chips being made. Otherwise a shrink probably would have already made sense since 28nm isn't even the cheapest node gate for gate but already a bit chonky. It gets cheaper with even smaller nodes.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#36It reminds me of how this backwards way of thinking seems to have infested everyone's heads; that stuff has to be, or make use of, the very latest technology available, or it will be useless junk that barely works.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#37Earlier quoted context omitted.
I honestly don't really understand 95% of what you've written here, but could this mean an end of godawful touch screens in cars?
No, it means there will be even worse touchscreens because now automakers can't afford silicon that might actually power a tablet.
Oh damn. Thanks.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#38Earlier quoted context omitted.
I honestly don't really understand 95% of what you've written here, but could this mean an end of godawful touch screens in cars?
No, it means there will be even worse touchscreens because now automakers can't afford silicon that might actually power a tablet.
How can they not afford a 300 dollar tablet in a 40k dollar car?
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#39Thanks TSMC... when will you release a HV version of 28nm? Oh... never, because you transitioned to bottom poly at 40nm. How is your automotive eFlash at 28nm... oh, you're still working on it (since 2018)? Well, guess we won't have many display drivers (or displays) or autos then, or maybe marketing should pull their heads out and smell the roses. I mean, I get it. Most things should transition to 28nm on 300mm wafe…
Seems like the automotive industry is gonna be the one to have to blink here. I’m not intimately involved in the details of the industry but didn’t the automotive industry already try to pass their risk onto TSMC by cancelling contracts early on into covid and we’re already told to get to the back of the line when they wanted their chip orders again? If TSMC has enough demand to sell everything they make, they don’t…
What does blink mean? Does your chips work when it is -70c - cars are used in arctic environments and so automakers have special tests to ensure they work in cold temperatures most of us will never see. Do you chips work when it is +65c - the inside of a parked car will get that hot, and the car is expected to work. How long will you keep the new chips in production - the longer the better we need to provide spare parts for everything for at least 10 years, so if you go out of production we need to fill a warehouse with the final production run just in case the things start mass failing in a few years.
I think the auto industry is looking to see if they can bypass the whole above mess with their own fabs. They don't need fancy processes, they need something reliable that they can depend on for years. The cost to a fab though means they need to worry about anti-trust as they can't go alone.
Re: TSMC to customers: It's time to stop using older nodes and move to 28nm
#40Earlier quoted context omitted.
Maybe my intuition is completely wrong here, but would the analog case be simplified if the target node+technology was chosen to have trace widths exactly 1/2 the size of the node being transitioned from? I.e. the traces would have essentially the same standing-wave tuning requirements when modelled as waveguides; would catch a harmonic of the original frequency when acting as antennae; etc.
Analog isn't just RF; PHYs for weird protocols is a giant component of the space, as well as power monitoring/management. The changes in how voltage/resistance/capacitance/etc work at each node for a given layout is the heavy lift. Additionally, you very, very rarely have the antenna on chip, and the analog bits even for RF are more signal conditioning that isn't typically modeled like waveguides, but instead more li…
> Additionally, you very, very rarely have the antenna on chip
I didn't mean that there would be components intentionally serving as antennae in a design; more that you might be choosing analog trace lengths in e.g. a modem, or SDR ADC, to minimize harmful analog-domain interference at your bus frequency — i.e. to increase SNR, you're trying to make your traces be as little like an antenna as possible for the frequency bands they're carrying signal in, because you can't just band-pass that interference away.
The nice thing about shrinking by half, in such deigns — I would think — is that if you've already "tuned" your trace paths to a quiet band (for the country the component is being licensed in), then the harmonic frequencies of that band will also be quiet. Otherwise the band's fundamental frequency wouldn't be considered quiet!
(See also: why the unlicensed commercial-use spectrum was allocated to 2.4GHz, and then to 5GHz. 2.4GHz is an obvious choice, already useless for long-range communication due to water in the atmosphere; the other is its equally-useless first harmonic. But the great thing about choosing the first harmonic in particular, is that transmitting at 5GHz isn't putting short-range harmonic noise onto any lower bands that weren't already noisy due to existing commercial use of the fundamental frequency; so you won't suddenly find your other-band devices working worse in the presence of 5GHz transmitters than they already worked due to 2.4GHz transmitters.)