What are the differences between carry look ahead adder and carry save adder?

[pravi]

can anyone tell the difference between carry look ahead adder and carry save adder with there advantages and disadvantages and where it is pratically used

 

[Kral]

Re: adders

pravi,
The carry save adder is used to add 3 numbers together where you are not interested in the intermediate result. This results in considerable saving in logic and gate delays.
.
The carry look-ahead adder is a method of "anticipating" what the carry of the current bit position operation will be without waiting for the result. It is accomplished by looking at the previous (lower order) bit positions and carrys. The result is faster propogation of carrys, and faster allowable clock rates.
.

See h**p://www.deepchip.com/items/0343-13.html for a good explanation.
Regards,
Kral

Added after 1 minutes:

pravi,
The carry save adder is used to add 3 numbers together where you are not interested in the intermediate result. This results in considerable saving in logic and gate delays.
.
The carry look-ahead adder is a method of "anticipating" what the carry of the current bit position operation will be without waiting for the result. It is accomplished by looking at the previous (lower order) bit positions and carrys. The result is faster progpgation of carrys, and faster allowable clock rates.
.

See h**p://www.deepchip.com/items/0343-13.html for a good explanation.
Regards,
Krasl