CSCI 255, ENGR 274, ECE 212 -- 14 September, 2000

Announcements

• Homework 3

Espresso

• One of the Berkely CAD tools
• espresso input → espresso output
• Generating espresso input
• Windows espresso binary -- save and run

The real world

• Gate delay
• Fan-in
• Fan-out

Getting into chapter 3

Multilevel logic

Conversion to NAND logic

AND-OR-Invert and OR-AND-Invert

• AOI and ORI blocks
• n-input m-stack

Techniques for multilevel logic synthesis

Decomposition

One Boolean expression → Several Boolean expressions

Extraction

Finding common subexpressions within a set of

Factoring

Factoring a two-level expression

Substitution

Replacing common subexpressions with new variables

Collapsing

Inverse of substitution -- replacing variables with their expressions

Time response

• Gate delays
• Transmission delays
• Timing waveforms