Saturday, 6 February 2021
Tuesday, 19 January 2021
Sanity Checks in Physical Design Flow
Sanity Checks in Physical Design Flow
- check_library
- check_timing
- report_constraint
- report_timing
- report_qor
- check_design
check_library:
check_library validates the libraries i.e., it performs consistency checks between logical and physical libraries, across logical libraries, and within physical libraries.
This command checks library qualities in three main areas:
Physical library quality
Logic versus physical library consistency
Logic versus logic library consistency
check_timing
PNR tool wont optimize the paths which are not constrained. So we have to check any unconstrained paths are exist in the design. check_timing command reports unconstrained paths.
If there are any unconstrained paths in the design, run the report_timing_requirements command to verify that the unconstrained paths are false paths.
report_constraints
It reports to check the following parameters.
Worst Negative Slack (WNS)
Total Negative Slack (TNS)
Design Rule Constraint Violations
report_timing:
report_timing displays timing information about a design.
The report_timing command provides a report of timing information for the current design. By default, the report_timing command reports the single worst setup path in each clock group.
report_qor:
report_qor displays QoR information and statistics for the current design. This command reports timing-path group and cell count details, along with current design statistics such as combinational, noncombinational, and total area.
The command also reports static power, design rule violations, and compile-time details.
check_design:
check_design checks the current design for consistency.
The check_design command checks the internal representation of the current design for consistency, and issues error and warning messages as appropriate.
Error messages indicate design problems of such severity that the compile command does not accept the design
Warning messages are informational and do not necessarily indicate design problems. However, these messages should be investigated.
Potential problems detected by this command include
check_design:
check_design checks the current design for consistency.
The check_design command checks the internal representation of the current design for consistency, and issues error and warning messages as appropriate.
Error messages indicate design problems of such severity that the compile command does not accept the design
Warning messages are informational and do not necessarily indicate design problems. However, these messages should be investigated.
Potential problems detected by this command include
- Unloaded input ports or undriven output ports
- Nets without loads or drivers or with multiple drivers
- Cells or designs without inputs or outputs
- Mismatched pin counts between an instance and its reference
- Tristate buses with non-tristate drivers
- wire loops across hierarchies, and so forth.