Power-aware Debug for Gate Level Designs
When the RTL design is converted to a gate-level design, part of the power intent defined in CPF(CommonPower Format )/UPF(UPF - the IEEE 1801-2009 standard) power files is 'synthesized' either by a synthesis tool or by the designers manually. For example, the isolation, level-shifter and retention rules are implemented by inserting isolation, level-shifters and retention cells during the conversion from RTL to gate level design. Along with the conversion, the content of the CPF/UPF files should be refined by the tool or designers respectively to reflect the changes. For the previously mentioned example, the related isolation/level-shifters/retention power rules should be removed from theCPF/UPF files since they are replaced by the isolation/level-shifters/retention cells respectively (refer to the following figure).
The refined CPF/UPF(CPF'/UPF') files and the gate level design needs to be verified to confirm equal functionality to the original CPF/UPF files plus the RTL design. The Verdi™ Automated Debug system provides exactly the same power-aware debug capability as in the RTL stage so that users can debug inconsistencies (between RTL and gate level) in the same Verdi environment.
Additionally, the Verdi system can recognize and highlight power cells which are unique to the gate level. The Verdi system can import the power cell information from the Synopsys Liberty files, UPF files (power cell commands) and the Library CPF commands. The power cells can be highlighted which help users to compare the inserted power cells and its related logic with the mapping part in the RTL design. For example, users can inspect whether the location and direction of isolation, switch, or level shifter cells is consistent with the related power rules defined in the RTL stage. Or, users can check whether the inserted retention cells are placed in the right scope and the connection is correct (equivalent to the related rule).
Refer to the following for an example of the highlight and annotation of an isolation cell in the nTrace window.
