How do intel/amd design their processors ?

Dunno about Intel nor AMD, but the third choice does(VHDL). ;-) Some of the circuits are fully custom (schematics), but there is also a VHDL model of these circuits used for simulation.

Of course. One doesn't design and lay out chips with half a billion transistors by hand.

Verilog is the other big one. Verilog is big in the US, while VHDL is bigger in Europe and for FPGAs (for some reason). Some software types think hardware design *is* just programming, so they're pushing "System-C" or some such nonsense.

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  Keith
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keith
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Hi,

Seeing all this stuff about how hardware can be programmed with languages... it makes me wonder how intel/amd design their modern processors ?

Do they also uses hardware design/programming languages ? for some part of their chips or everything ?

Do they also still use cad/cam etc ?

What hardware languages do they use if any ? :D

Bye, Skybuck =D

Reply to
Skybuck Flying

I suspect you're a student of some sort, starting out in dealing with the world of engineering. So here's a bit of a lesson in engineering.

There's a bit of a hierarchy of design when dealing with things as complex as CPUs. It looks a little something like this (note, there is considerable hand waving and generalization in the statements below):

- A company like Intel or AMD has some really low level group that deals with a simple question like "how do we make a transistor that works at 4GHz?"

- When they've figured it out, they translate that knowledge to some kind of CAD tool that automatically designs the right kind of transistor and lays it out in the right place.

- That software is used by a group that deals with a slightly more high level question like "how do we make a 4GHz logic gate using our 4GHz transistor technology?"

- They then translate that into a CAD tool for higher level use.

- That is then in turn used by a group that deals with something like "How do I make an adder using our 4GHz logic gate technology?"

- That is worked into a high level CAD tool like VHDL/Verliog/various proprietary languages.

- There's a few more levels of abstraction here.

- So now, some architect at Intel/AMD can say "I want a CPU that executes an ADD instruction in 5 clock cycles at 4GHz, is fully pipelined and has a few bells and whistles", that can then get translated down the chain of engineers and CAD tools so that in the end, you come out with a CPU with billions of transistors without having to lay out each transistor individually.

This higherarchy can work both forwards and somewhat in reverse, that is a high level design concept drives a change in low level technology or a new low level technology can drive a change in thinking at a higher level. In a nutshell, that is engineering.

For specific commercial tools, look at the web sites of Synopsis, Cadence and similar companies. Needless to say, this software is insanely expensive because it's very specialized. You may note that someone like Synopsis has a lot of high level tools and some low level tools like Hspice that let you deal with individual transistors.

The moral of the story is that a hierarchy of abstraction makes engineering possible. The thing that allows an Intel engineer to design a CPU without having to lay out each individual transistor is the same as what allows someone to design a bridge without knowing how to pour concrete and to design a car without knowing how to grind metal gears (more or less, see below)

That said, there's always some leakyness in these abstractions and that's why you're taught a bit of everything as an engineer. Your high level design decisions may affect what choices are made at a lower level, and you are expected to be somewhat aware of what these are. The high level guy at Intel has to be somewhat aware of the fact that he can't just say "I wan't an processor that executes an ADD instruction in 1 clock cycle at 100GHz" simply because the low level guy will say it can't be done.

Cheers,

Chris

Reply to
kmaryan

languages...

of

What would be the third choice ? IBM ? ;)

Can a processor be produced with VHDL alone ? or is Cad/Cam still needed ?

Hmm... VHDL probably needs to produce a Cad/Cam model ? so that it can be produced/manufactured ;) (since the code is just text ;) )

So I do see the stupidity of my question ;) :)

But euhm... Does VHDL produce Cam/Cam output directly or are/can there be multiple stages ?

Maybe like an intermediate language ? Probably ;)

Cool, both languages seem a little bit familiar.

Though I am more a pascal/delphi programmer so I'll probably feel more at home with VHDL... though Verilog seems to be a little bit shorter just like C :)

Can both compilers generate output which is compatible with each other or cad/cam programs ? probably ? ;)

Cad/Cam programs can probably handle output of both languages ?

Bye and Thanks, Skybuck ;)

Reply to
Skybuck Flying

Works for me. ...and verse visa. ;-)

VHDL is only a description of the function. It's really not *that* much different than a schematic, or a blueprint for an airplane. The logical representation of the widget still has to make it into the real world. CAD (Computer Aided Design) is used to change the logical description into a physical description. CAM (Computer Aided Manufacturing) takes that physical description and turns it into reality.

Not stupid at all. You got there.

Think of an onion. The designer's job is usually to peel only one layer of the onion and pass it off to the next station. In this case A high-level designer may use VHDL to simulate the deign and them pass it off to another who will synthesize it into a netlist with lower level components. Another will take that netlist and create a physical representation of the design. Another will take the physical representation and make the masks for the photocopier. ...and so it goes until the onion is peeled.

VHDL is the human interface. It gets compiled or "synthesized" into a netlist. The netlist gets "placed and routed" into a physical design (GL/1). That gets sent off to make masks, which in turn are used to make the device.

Two sides of the same coin. Each has its benefits and drawbacks. They've come much closer together over the years, each stealing from the other. It's much a religious war these days (but Verilog sucks!;).

C sucks too. ;-)

Yes. In fact it's not too difficult to do one part of a design in Verlion and another in VHDL, and still a third part with schematic entry.

Sure. The synthesis outputs will look the same. The difference is in the front end language processor.

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  Keith
Reply to
Keith Williams

In article , Skybuck Flying wrote: [...]

In FPGA design:

As far as the user of VHDL is concerned, the VHDL made the processor. The VHDL discribes what is to be done. There is a bunch more information going into the tools discribing how various things can be done. This information is mostly inside what is called the "fitter". The "fitter" is usually specific to the family of FPGA you are using.

The software tools break the VHDL down into a simpler form and then tries to match each thing that needs to happen to a method to do it. Obviously there is always a huge number of ways that each small part of the design can be done. The real trick in the tools is finding a way to get the whole design to fit into the available silicon. This is a bit like doing a PCB layout. You need to move the parts around so you can get the signals between them. It is very different in that you can only place parts in certain places and route signals through certain places.

Yes, the input to the fitter is a simpler language. At that point everything has been reduced to simpler logic.

[...]

As a person who also does Pascal and VHDL: VHDL has keywords like Pascal but it is a very different language.

Unlike Pascal, VHDL has a lot of silliness in its syntax. The big one of these is the word "is". You just have to memorize where it is needed.

Unlike Pascal, VDHL has the connections and the logic defined to two parts. It claimed that this is to allow changes to the implementation of sections to be made more easily. As far as I can tell, the autors just never heard of editors with cut and paste.

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kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

Pencil & paper schematics, then discrete transistor breadboards. Same old same old.

;-)

Just joking, of course.

Good day!

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Christopher R. Carlen
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Chris Carlen

Dunno about AMD, but I've heard that Intel get Indians to do it. :-)

In case anyone thinks I mean disrespect, not at all! I'm constantly amazed at the way Intel continues to surmount unnecessarily difficult challenges...

Reply to
Clifford Heath

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