3.3 Backannotation

Backward annotation with the Backannotation is always required after performing layout net list modifications such as part name changes, pin/gate swaps, or alternate part package type assignments. Part names can be changed using the Netlist Part Name function from the menus for interactive part placement. Interactive pin/gate swaps are applied with the Pin/Gate Swap function from the manual part placement menu. Automatic pin/gate swap is performed with the Full Autoplacer, Single Pass Optimizer and Multi Pass Optimizer autoplacement functions, and can also be performed when using the Router P/G-Swap On option with the rip-up router of the Autorouter module. Alternate package types can be assigned using the Alternate Part submenu function during manual part placement. Note that any of the net list modifications mentioned above will get lost when re-editing the schematic without running the Backannotation.

3.3.1 Starting the Backannotation

Backannotation is fully integrated to the Schematic Editor and can be explicitely started using the Backannotation command from the Utilities menu.

Automatic Backannotation Requests Processing

A feature for automatically processing pending Backannotation requests is integrated to the Schematic Editor functions for loading schematic plans. Backannotation requests are generated when saving layouts with net list modifications such as pin/gate swaps or changed part names. Loading an SCM sheet with a pending Backannotation request automatically activates a verification menu which allows to backannotate the currently processed design. The Backannotation request is deleted after successfully running the Backannotation.

3.3.2 Running the Backannotation

Design and/or project file name and layout element name prompts are activated after calling Backannotation (pressing the ESC key aborts the Backannotation):

Utilities

Backannotation

Design File Name ?

Layout Element Name ?

The design file name is the name of the project file to be selected for Backannotation. The design file must be available with extension .ddb but this extension must not be included with the file name specification. If the user types an empty string (by pressing the return key ) to the design file name prompt, then the system will automatically use the file name of the currently loaded or the previously processed element (i.e., the global project name).

The layout element name is the name of the layout and/or the net list to be backannotated. If the user types in an empty string (by pressing the return key ) to the layout element name prompt, then the system uses the default layout element name defined with BAE setup (see also command LAYDEFELEMENT of the bsetup utility program).

After successfully processing the layout the Backannotation will generate a modified logical net list in the project file. For user information purposes Backannotation also creates an assignments file under the design file name with extension .ass. The assignments file is an ASCII file containing an annotation report (part name changes, logical to physical pin mapping).

The system issues the No errors occurred! message after successfully completing the Backannotation process, and the user can press any key to exit from the Backannotation function. Errors during Backannotation usually result from a wrong layout element name specification and/or from missing logical net list data. Missing SCM symbols and/or parts could also prevent the Backannotation from completing successfully. The Backannotation lists missing symbols/parts. These must be replaced on the SCM sheet(s) to allow for subsequent Backannotation processes to be completed successfully (the missing parts problem could also be "solved" by simply re-running the Packager instead of the Backannotation, but all netlist-specific layout modifications scheduled for Backannotation such as pin/gate swaps would then be lost).

3.3.3 Example

This section describes how to run Backannotation on the demo.ddb example project file which has been created in the previous chapter. You should change to the directory where the demo.ddb file resides.

Start the Schematic Editor through the BAE main menu and use the following commands to call Backannotation for transferring the physical net list named board from the demo.ddb design file back to the schematics:

Utilities

Backannotation

Design File Name ?

demo

Layout Element Name ?

board

Backannotation displays the following messages:

==============================
BARTELS BACKANNOTATION UTILITY
==============================

Design File Name ........: 'demo'
Layout Element Name .....: 'board'
No error occurred!

The No error occurred! message means that Backannotation was successfully completed and the logical net list in project file demo.ddb has been annotated with the physical net list named board.

Backannotation produces an assignment file named demo.ass which is not required by the BAE design system. You can use the part name changes report and the logical to physical pin mapping lists provided with this ASCII file for backannotating to foreign CAE systems.

Backannotation annotates physical net list modifications such as part name changes and pin/gate swaps to the schematic sheets. You can check this by examining the SCM sheet elements after successfully running the Backannotation.

Bartels :: Bartels AutoEngineer :: BAE Documentation :: BAE User Manual :: Packager :: Backannotation