Browse Prior Art Database

Net Synthesis and Device Recognition for Layout Verification

IP.com Disclosure Number: IPCOM000051981D
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Wong, RC: AUTHOR

Abstract

In VLSI (very large-scale integration) designs, graphic data cannot be efficiently manually verified because of the volume amount of data. It is very difficult and time consuming to correlate graphic data to the original logic circuits. To manually verify VLSI layouts is in a practical sense beyond human mental capacity. The only way is to rely on computer aids.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 69% of the total text.

Page 1 of 2

Net Synthesis and Device Recognition for Layout Verification

In VLSI (very large-scale integration) designs, graphic data cannot be efficiently manually verified because of the volume amount of data. It is very difficult and time consuming to correlate graphic data to the original logic circuits. To manually verify VLSI layouts is in a practical sense beyond human mental capacity. The only way is to rely on computer aids.

These net synthesis and device recognition computer programs are the key portions of the required computer aids. Essentially, these programs derive logic circuits from graphic data according to the chip manufacturing process. Presented below is an overview of the system.

The net synthesis program traces logic networks from graphic data. The algorithm is as follows: 1. Pick a shape or a group of touching shapes on one of the critical mask levels. 2. Trace up and down its related mask levels for shapes which form an electrically common network. 3. Mask off shapes already processed. Proceed to (1) if any relevant shapes remain unmasked. 4. Trace out nets not reachable from the critical mask levels and mark them for listing. 5. Check opens and shorts. 6. Tabulate net data, and save in net table.

The device recognition program identifies transistors and other devices from the graphic data. The algorithm is as follows: 1. Pick a shape or a group of touching shapes on a mask level essential to a device. 2. Investigate surrounding shapes at neighboring...