Best adder circuits?

[tank171]

I have been trying to find out what the fastest adder circuits are, and how they work, but I havent been able to find anything. Anyone know what intel/amd/ti etc, uses for adder circuits? And do you have a diagram of a circuit that I could try to understand?

Thanks in advance.

 

[TuxDave]

How much EE knowledge do you have? Showing you a circuit may not tell you much if you have no sense of how domino or static circuits work. The adder topologies are all variations of the carry look ahead adder. I think you should start there to understand how binary addition works before you start going to exotic adder designs.

The absolute fastest adders I have ever read in any papers have been based on low voltage swing pass gate adders. Intel released a paper when I was in school to operate around 7GHz and I wouldn't be surprised to see even faster ones out there.

The ones that have been using domino logic design have usually been based on the Ling Adder (also googlable) due to the large complex gates that you need for the first stage of logic and large fan in. Again during that same time as that Intel paper was released a fellow graduate student designed a 4GHz adder based on that design on 90nm CMOS technology.

But the most popular and robust adders using static CMOS design is your regular radix-2 carry-look ahead adder. I don't really have any numbers on that since it's not a very interesting design so I doubt anyone could get a paper in a decent conference based on that.

 

[Cogman]

http://www.acsel-lab.com/Proje...dder/adder_designs.htm

I found this site to be pretty informative. YMMV.

 

[Navid]

Let's start with this question:
Do you know what an XOR gate is?

If yes, have a look at this to start with.
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