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Table Of Contents

1. Disclaimer:

This software is distributed on "as is" basis. The author disclaims any and all warranties. In no event shall the copyright holder be liable for any incidental, punitive, or consequential damages of any kind arising from the use of this program. Use of this software indicates you agree to this.

2. Revision History:

• Rev 0.92 (5/8/98) First beta release
• Rev 0.93. Fixed return value on some netlist/partlist converters
• Ref 0.94. Added XDrc utility.
• Ref 1.00 Code converted to executable and added a graphical interface
• Ref 1.50 Redesigned front-end for VB and branched into standalone Netlist Comparator tool
• Ref 1.60 (5/30/02) Fixed issue with added/deleted/renamed nets and improved mentor (to support attributes) and pads netlist readers
• Ref 1.70 (6/9/02) Added Part List comparison and changed user i/f to accomodate Part comparison requirements

3. Introduction:

Netlist comparator is a tool that can be very usefull when incremental changes to an schematic (existing board) are performed and you want to make sure that the changes are actually what you expect. They are usefull to document this changes and also to track the process of backannotating changes performend to the Netlist (if any) in Layout to the roiginal schematic. It can also be used to compare the same netlist in different formats (to check that integrity of the netlist is preserved while moving to a different tool).

4. Description of the Software

NetComp Is a netlist comparator. It reports added, deleted, modified and renamed nets in an easy to read format. With rev. 1.70 and above you can also compare differences in the component lists (Partlist) for instance differences in the part values or package types.
 

4.1. Netlist comparison

The point of entry to the program is a Netlist.

Currently, The following Netlist formats are supported: Allegro, Mentor, Tango/Accel and Pads PCB. New formats can be implemented on demand.

To execute it, double click on LittleBlueCAD>NetComp under Windows Start Menu

A dialog box shows-up. The requested information is the following:

Old netlist filename: Is the filename of the netlist coresponding to a previous version of the schematic

Old netlist format: choose the right ne from the list

New netlist filename: Is the filename of the netlist coresponding to a the modified schematic

New netlist format: choose the right ne from the list

Note that the tool allows comparison of netlists which have each one a different format. This can be used to verify netlists conversions too.

When the tool is open, all the entries are filled-up with the information corresponding to an example provided with the package. You can just click Run to see the results for the mentioned example

A Log file (log.txt) showing output results will be shown, and uppon success, the report (named "net_diff.txt") file will be opened on the default file viewer

The Netlist Report tells you details about the changes on the netlist and finally if the netlists are:

IDENTICAL : They have same net-names and connections (it doesn't mean that both files are exactly the same tough, just that the connections are the same for both files)

EQUIVALENT: Only renamed nets appear. So the netlist represent the same connectivity, but name changes are present

DIFERENT: Netlists don't reflect same connectivity

4.2. Partlist comparison

In addition to the fields mentioned above, for Mentor format you need to specify which file contains the component list (in other formats the partlist is present in the same Netlist file). Note that by default the Partlist box will be filled-up with the same name than the Netlist but replacing the extension by .cmp (please note that this is only for Mentor netlist format)

Two fields called Old Partlist / New Partlist need to be filled-up if you want to perform a Partlist comparison.

The Partlist Report tells you detailed information about componenets added/deleted or changed in any of their properties

A summary of the results is also displayed indicating that the Partlists are:

IDENTICAL : They have same component reference designators and all of them have the same attributes

DIFERENT: Partlist contain different components or different properties on any of the components

5. Limitations:

The following characters shall not appear in a net name:

! ' " <Space>

The following characters shall not appear in a component ref. designator:

! . , -

6. How to Register:

These utilities are Shareware. If you find yourself using it for more than the trial period, you must register. Send a $29 check (or the equivalent in your currency) to: