Forward And Backward Compatibility

Software is considered backward (or downward) compatible if newer versions or releases can read, view, and operate on data that was created with prior versions or releases. This should not be confused with forward compatible which means that older software can read, view, and operate on data that has been created with newer releases.  Most design automation software is backward compatible. When new versions are released, users may install the newer release, and continue to operate on their existing data. If, however, they utilize features in the newer release that were not present in the prior release, they may encounter forward compatibility issues if they revert back to the prior release. Not all new features will cause problems, but some may. For example if data created in the new release is stored differently in the database, the older release may not be able to recognize it. Most design automation software is not forward compatible.

Laker 2009.09 is not forward compatible but it is backward compatible. There are new objects in Laker 2009.09 that when used will render cells non-readable in prior versions like Laker 3.2v4. For example, there are new parameters for contact width and spacing available for MCells. If Laker 2009.09 is used to create them in a design, that design will no longer be viewable in Laker 3.2v4 since Laker 3.2v4 does not support these parameters. Another example, User-Defined-Devices (UDDs) may be encrypted with Laker 2009.09 so that other users may not view or modify the device. This was not available in Laker 3.2v4, so UDDs encrypted with Laker 2009.09 will not be accessible, readable, or compatible in Laker 3.2v4.

There are situations where a user created a design in a newer release and was then able to use a prior release to view or modify the design. In these particular situations, new or modified features had not been used. Once a design is moved to a newer software release, it is recommended that it stay with the newer release and not be attempted to be opened or modified with a prior release, as newer or enhanced features may have been utilized and these features may not be available in prior releases.