Java Applet for Adder Synthesis
Description
Java applet for the optimization and synthesis of prefix graphs and
the generation of parallelprefix adders.
It allows the size optimization of prefix graphs under arbitrary depth
constraints, which can be different for each column (i.e. bit position).
The algorithm is described in the reference below.
Documentation

VHDL Library of Arithmetic Units

R. Zimmermann, ``NonHeuristic Optimization and Synthesis of ParallelPrefix
Adders'', in Proc. Int. Workshop on Logic and Architecture Synthesis
(IWLAS'96), Grenoble, France, Dec. 1996, pp. 123132.
[abstract,
postscript]
Usage

Usage is rather straightforward, just play around with it.

Single local prefix transformations:

depthdecreasing transformation: click `mouseleft' on a black node

areadecreasing transformation: click `shiftmouseleft 'on a black node

Depth constraints for individual columns:

top constraint: hold `mouseleft' and move from left to right over vertical
line

bottom constraint: hold `mouseleft' and move from right to left over vertical
line

Parameters:

Max o/l: maximum number of black nodes per level (i.e. row)

Max o/b: maximum number of black nodes per bit position (i.e. column)

Writing VHDL code for adder circuit:

only works in `appletviewer,' not in Javaenabled browsers (security)

see instructions
for enabling `appletviewer' to write files
Download

Files for use in `appletviewer'
Applet
Reto Zimmermann
/ Feb 4 1998 / Home Page