Fast adders?

[CTho9305]

I'm having trouble finding papers online that explain faster adders (ling, kogge-stone, brent-kung) in a way that I can understand what's going on. Anyone want to explain them to me?


edit: I somewhat understand a ling adder, but I get the impression that at the gate level, there isn't really any gain over a "vanilla" CLA using carry-select adders at the lowest level. For this project, transistor-level design is not possible.

 

[Sahakiel]

Um... let's see...

They add numbers....


...fast....

 

[Howard]

You mean snakes with high velocity?

 

[Chaotic42]

Originally posted by: Howard
You mean snakes with high velocity?

Hahaha

I thought this thread was about fast mental adding. Like read a list of 100 3-digit numbers and add them together in a few seconds.

 

[KalTorak]

Ultimately, aren't all adders basically combinatorial blocks of N+N with carries between blocks?
Kinda like ripple-carry full- and half-adders, but with N bits at a time being added?

 

[blahblah99]

I'm not into this adder stuff, but from a quick look at the brent-kung adder, it looks like it uses the basic propogate/carry adder blocks , but instead of going through 7 levels of propogation and carrying, it rearranges the flow via associativity and squashes it down to like 3 or 4 levels.

 

[Amorphus]

I thought it was fast mental computation, then fast snakes, at first. then I saw the stuff he wrote, and I thought he was talking about kung-fu.

after that, I lost track, because I don't mess with ICs... =/

*edit*
WHOA, HOLY COW. this is the HT section. I thought I was in GH!

 

[GoHAnSoN]

Originally posted by: Chaotic42

Originally posted by: Howard
You mean snakes with high velocity?

Hahaha

I thought this thread was about fast mental adding. Like read a list of 100 3-digit numbers and add them together in a few seconds.

LOL