How do intel/amd design their processors ?

[keith]

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 ?

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.

Do they also still use cad/cam etc ?

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

What hardware languages do they use if any ?

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.

 

[Skybuck Flying]

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 ?

Bye,
Skybuck =D

 

[Skybuck Flying]

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.

What would be the third choice ? IBM ?

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

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

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.

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

 

[[email protected]]

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

 

[Ken Smith]

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

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.

Maybe like an intermediate language ? Probably

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


[...]

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

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.

 

[Keith Williams]

What would be the third choice ? IBM ?

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

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

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.

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

Not stupid at all. You got there.

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

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.

Maybe like an intermediate language ? Probably

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.

Cool, both languages seem a little bit familiar.

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!.

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

C sucks too. ;-)

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

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.

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

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

 

[Chris Carlen]

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 ?

Bye,
Skybuck =D

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


;-)



Just joking, of course.


Good day!

 

[Clifford Heath]

it makes me wonder how intel/amd design their modern processors ?

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...