Schematic diff tool enables IC Designers to graphically browse-through and review changes made across versions of the same schematic design. This tool provides a means to the designers to navigate through any addition, deletion or modification which may have taken place between the versions compared. During the navigation, the tool also highlights the deltas on the schematic editor in case they happen to be part of any visible design component.
Non-visible schematic components considered for delta computing
These components are part of the delta set but they will not get highlighted in the schematic editor upon their selection in the navigation panel since they are either design properties or metadata.
Visible schematic components considered for delta computing
These components when selected in the navigation panel will appear highlighted in the schematic editor.
The schematic diff tool can be invoked from Library Manager as well as Work Area Manager only on schematic designs through the context menu items “Compare with Predecessor” or “Compare with Another Version…”
“Diff Assistant” is a dock able window placed on the schematic editor for assisting designers to navigate through the deltas. It comprises of two sections, the navigation panel and the delta description field. As the designer navigates through the deltas, the description field informs the designer about the delta details. Also, if the currently selected delta is/was (in case of a deletion) a visible component in the design it gets highlighted on the schematic editor.
Navigation panel allows the designers to browse through the deltas. Deltas are listed under their components types in a tree table widget. These components can broadly be classified into four categories.
The tree table widget will list every delta with its name and the change type. The nature of the change can be either of the following
Designers can leverage either navigation buttons to browse through the deltas or they can directly expand the root component and individually select the deltas.
Navigate to the first difference in the design. The button will remain disabled if the current difference is also the first difference.
Navigate to the previous difference in the design, if any. The button will remain disabled if the current difference is also the first difference.
Navigate to the next difference in the design, if any. The button will remain disabled if the current difference is also the last difference.
Navigate to the last difference in the design. The button will remain disabled if the current difference is also the last difference.
In addition to the navigation buttons designers can expand the root components and explicitly select a delta underneath it to read its description and also see it highlighted in the schematic editor.
Description box is placed exactly below the navigation panel to publish the details of the delta.
If the currently selected delta in the navigation panel happens to be part of the visible set of components, it will be highlighted in the schematic editor. Highlighting scheme does not apply to non-visible design components.
Highlighting Deleted Deltas
The schematic diff is always invoked on the view selected version of the design and hence any deletion in the view selected version becomes a special case since the component no longer exists in the design. A special highlighting scheme is followed in this case which is in alignment with Virtuoso’s highlighting scheme to indicate any missing component referenced in the design. A BBOX with crossed diagonals (missing sign) will be placed at the coordinates where the missing component used to exist in the 'compared with' version.
Does your organization do Custom IC designing? Do you use Cadence Virtuoso? Do you use ClearCase? If yes or for additional details on this integration and its salient features, reach out to me or comment below.