is available at any stage of the flow after
-incremental has been used. The report allows the user to compare the
following between the reference and current design runs:
- Examine cell, net, I/O and pin reuse in the current run
- Timing WNS at each stage of the flow
- Tool options
- Tool versions
- QoR suggestions applied with the incremental flow
By examining the cell reuse and the other factors mentioned above, a user can determine the effectiveness of the incremental. Where the flow is judged ineffective, a user would typically update the checkpoint to a newer version of the design or adjust the tool flow. The report is split into seven sections.
This reports the general information for the current whole incremental flow:
This contains an overview of the cells, nets, pins, and ports that are reused. An example is:
The columns provide the following information:
- Matched - Cells that have the same instance name, REF_NAME
property or have been deemed a match if some information differs slightly. This
is calculated at the end of
- Initial reuse - Once items are matched, this indicates if the matching information on location was reused or not. Sometimes items are matched not possible to be reused due to illegal connectivity or other design requirements.
- Current reuse - This indicates the reuse at the current design phase. Useful when compared with initial reuse to see how much reuse is lost as you go through the tool flow to generate a legal solution.
- Fixed - items that incremental flow can not touch. When high, the tools might struggle to generate a legal solution.
Reference Checkpoint Information
This contains information about the reference checkpoint. From this section you can examine the following:
- Vivado version that generated it
- Stage of the implementation
- Recorded WNS and WHS
- Speedfile version information of both the reference and incremental runs
An example is:
Comparison with Reference Run
This contains useful metrics about a comparison with the reference run. From this section you can compare the following:
- Runtime information
- WNS at each stage of the flow
- Tool options at each stage of the flow.
Optimization Comparison with Reference Run
This section contains the
iphys_opt_design replaying information which is retrieved from the
reference dcp, along with the RQS suggestions derived, generated, and applied in the
current incremental flow. An example is:
Command Comparison with Reference Run
This section contains the commands executed for flow command comparison. An example is:
iphys_opt_replaymight not replay all optimizations from the reference run. Any Non-reused optimization has an impact on the cell or net reuse.
Pay particular attention to the commands used prior to read_checkpoint -incremental to confirm they are the same and reuse is maximized.
This contains metrics about what was not reused and why. The following is an example: