FPGA Central

Prasanth Kumar <[email protected]> wrote in message news:<[email protected] n>...
> On Mon, 2004-11-01 at 19:54 -0800, sirisha wrote:
> > Arithmetic operations are among the most basic instructions in
> > microprocessors and many other ASICs. From SPECfp2000 benchmark, about
> > 15% of the floating-point ALU operations are additions and about 10%
> > are subtractions. The most time consuming arithmetic operation is the
> > floating-point division, then comes to the multiplication and then the
> > addition/subtraction. The speed of those arithmetic operations
> > directly links to the overall performance of the ALU units and so the
> > computers. Since floating-point addition/subtraction units are built
> > on top of integer addition/subtraction units, performance of integer
> > addition/subtraction units have direct link to performance of
> > floating-point units.
> >
> > In this class project, we design 2 32-bit addition/subtraction units,
> > one uses straight simple ripple-carry algorithm and the other uses
> > carry-looked-ahead algorithm. Our study will basically explore the
> > correlations between areas, speeds, algorithms and will at least cover
> > the information as listed below. All analyses will be performed based
> > on both theory and measurements and explanation will be provided for
> > discrepancies between the twos.
> > ƒ 1)Correlation of areas and speeds for both algorithms will be
> > determined
> > 2)The two designs will be optimized for areas and analysis on speeds
> > will be performed
> > 3)The two designs will be optimized for speeds and analysis on areas
> > will be performed
> > 4)Costs and speeds of a 32-bit floating-point unit if the unit is
> > built based on one addition/subtraction algorithm versus the other
> > will be relatively evaluated
> >
> > This project start with verilog code. I am unable to start the
> > code.I need help from group.
> >
> > Thanks
> > sirisha.
>
> Here is some help to start the code:
>
> module ripple(sum, opa, opb);
>
> // you fill in the code here
>
> endmodule

can u give some more ideas of this project.difference between ripple
and carry look ahead adders.

thanks
sirisha.

sirisha wrote:

> can u give some more ideas of this project.difference between ripple
> and carry look ahead adders.

This is teached in every course about basic digital circuit techniques.
If you missed lecture, search the internet. It took me 5 Seconds to find
some helpful pictures and a text about this topic. I took
http://images.google.com with search string "Carry Ripple Adder" and
found
http://images.google.com/imgres?imgu...lr%3D%26sa%3DN


Ralf

On 2 Nov 2004 09:46:23 -0800, [email protected] (sirisha) wrote:

>Prasanth Kumar <[email protected]> wrote in message news:<[email protected] n>...
>> On Mon, 2004-11-01 at 19:54 -0800, sirisha wrote:
>> > Arithmetic operations are among the most basic instructions in
>> > microprocessors and many other ASICs.
>> > In this class project, we design 2 32-bit addition/subtraction units,
>> > one uses straight simple ripple-carry algorithm and the other uses
>> > carry-looked-ahead algorithm.
>
>can u give some more ideas of this project.difference between ripple
>and carry look ahead adders.
>

Best online introduction I have found was some course notes from
Reto Zimmermann at ETH Zurich, downloadable from this page.

http://www.iis.ee.ethz.ch/~zimmi/arith_lib.html

- Brian