carry_save_adder :: Overview

Project maintainers


Name: carry_save_adder
Created: Jan 8, 2019
Updated: Jan 31, 2019
SVN: No files checked in
Bugs: 1 reported / 0 solved
Star0you like it: star it!

Other project properties

Category:Arithmetic core
Development status:Planning
Additional info:
WishBone compliant: No
WishBone version: n/a
License: LGPL


This project is a 32-bit carry save adder. I initially made a 1-bit CSA and used two of those to make one CSA unit which can be cascaded to make n-bit adders, which is what has been done in this project.

The 1-bit CSA follows the following equations to compute the sum and carry:
sum: when a=b, s=cin
a!=b, s=!cin
cout: when a=b, cout=a
a!=b, cout=cin

Using this, the sum and carry can be computed faster.

When this 1-bit CSA is used to add n-bit numbers, it has to be used in two layers. When used in CSA units, it becomes simpler to read and to use for n-bit adder designs.

© copyright 1999-2018, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.