PrimeTime can generate a timing model from a submodule netlist, and then use that model in place of the original netlist for timing analysis at higher levels of hierarchy. This technique makes whole-chip analysis run much faster.
Another use of timing models is to protect intellectual property. If you supply a chip submodule to a customer for integration into the customer’s larger chip, you can provide the timing model without the original netlist. This method allows the customer to perform accurate timing analysis with the submodule, without having access to the netlist.
PrimeTime supports the following types of timing models:
•Quick timing model. This is an approximate timing model created in PrimeTime using a sequence of PrimeTime commands. This type of model is useful early in the design cycle, when a netlist is not yet available for a submodule.
•Extracted model. This is a timing-only model extracted by PrimeTime from a gate-level netlist. This type of model discards all of the logic of the original netlist and replaces it with a set of timing arcs between clocks, inputs, and outputs.
•Interface logic model. This is a structural timing model extracted by PrimeTime from a gate-level netlist. This type of model preserves the interface logic of the original netlist and discards the internal register-to-register logic that has already been verified at the module level.
•Liberty model. This is a timing model defined in a descriptive language, either written manually or translated from a timing description in another form.
Command Interfaces |