TIMING ANALYSIS OF CIRCUITS USING SUB-CIRCUIT TIMING MODELS

摘要

Examples of techniques for analyzing and generating timing reports for circuits are described herein. A computer-implemented method includes splitting a netlist or cross section of a circuit into sub-circuits. The method further includes building a timing graph by combining generated timing models of the sub-circuits. The method includes determining a full set of dependencies based on each sub-circuit's dependent configuration parameters. The method also further includes generating a sample plan for each sub-circuit. The method includes receiving results from a simulation for each sub-circuit based on the sample plan for each sub-circuit. The method includes generating algebraic forms for an early delay, a late delay, and a slew by curve fitting across the configuration parameters. The method includes propagating arrival times and slew in algebraic forms throughout the timing graph. The method includes evaluating checks based on selected projections from the timing graph to find a worst slack configuration.

主权项

1. A system, comprising a processor to:
split a netlist or cross section of a circuit into sub-circuits; generate a timing model for each sub-circuit and build a timing graph by combining the timing models of the sub-circuits; determine a full set of dependencies based on each sub-circuit's dependent configuration parameters and configuration parameters that a load and inputs of the circuit are dependent on; generate a sample plan for each sub-circuit with dependencies based on the full set of dependencies; receive results from a simulation for each sub-circuit based on the sample plan for each sub-circuit; generate algebraic forms for an early delay, a late delay, and a slew by curve fitting the results from the simulation across the configuration parameters; determine a piecewise-linear minimum and a piecewise-linear maximum for each of the algebraic forms of arrival times from segments arriving at a common node in the timing graph and propagate the arrival times and slew in algebraic forms throughout the timing graph; and evaluate checks based on selected projections from the timing graph or over a complete set of configurations to determine a configuration with a worst slack.