Sometimes it can be necessary to delve deeper into the suggestion to understand the reason for generation. There are typically a few things that should be investigated
- Utilization and Netlist Suggestions
- These typically require investigation of the cells in the netlist that the suggestion is targeting. This can be done by selecting objects and opening a schematic.
- Clocking and Timing Suggestions
- These typically require investigation of the timing path associated with the suggestion. The timing reports form part of the QoR Suggestion report.
- Congestion Suggestions
- These typically require investigation of the cells and their location.
To get a cell list of targeted objects in a suggestion, follow the steps to
write out a Tcl file. When the Tcl suggestion file is written, each suggestion is
labeled in the file with its ID. From this a user can copy the [get_cells <>] or
[get_nets <nets>] portion of the suggestion. The following is an example of Tcl
that can be used to further explore the
objects:
set cells <cells from Tcl file>
report_timing -from $cells
report_design_analysis -of [get_timing_paths -from $cells -max_paths 100] -name -RQS
show_objects -name RQS_objs $cells
select_objects [get_sites -of $cells]