• Introduction
• Applications
• Input
• Outputs
    Ansoft ANF
    Optimal XFL
    OEA Netan
Running NETEX
• command syntax
Proximity Nets
• What is a Proximity Net?
• Why Would I Need It?
• How it Works
When Net Names Collide
• Different Net Names
   on Same Conductor

• Separate Conductors
   with Same Net Name

• Log file reporting
Layers and Datatypes
• What is a GDSII Datatype?
• How to Separate Entities
   by Datatype
The Technology File
• Conductor Stackup
• Assigning Net and Node
   Names using Text Layers

• Conductor Name Mapping
The Configuration File
• Data Units
• Expansion
• Output Directory
• Temporary Directory
• Extraction Directives
     • All
     • Bycoordinate
     • ByName
Saving Intermediate Results
• The GDSII file with all nets
• How Last State is Saved

NETEX Intermediate File

When NETEX first processes a GDSII file it extracts all of the nets (with one exception: see the -tstpt option) and writes an intermediate output file even if the user has requested only a single net.

gdsii output

left: the entire net output. right a single net output takes 95% of the work to generate.


It turns out that to extract a single net, NETEX must booleanize the entire database, perform the intersection routines on the entire file -- in effect it takes 95% of the computation to extract a single net and only an additional 5% to extract 100% of the nets.

By saving the results, NETEX can do additional extractions with very little effort.

How NETEX Tracks Intermediate Files

When NETEX processes a file, it examines the configuration file (.cfg) and looks for an entry called LASTRUN. If LASTRUN is found, then it checks to see that the file name, the technology file, the structure and the window are identical to this run. If so, it knows that it can use the intermediate file and does not need to repeat the computations to explode, flatten, booleanize etc... but can go straight to the net extraction routines.

The LASTRUN section will be written by NETEX and should not be edited or modified by the user. A sample is shown below.

INPUT nettest.gds
TOP top_test

417 Ingalls St., Santa Cruz, CA 95060    Tel (831) 426-6163     Fax 426-2824    email: