US 9,003,344 B2 · Generating pattern-based estimated RC data with analysis of route information

Abstract

A method and apparatus for improving physical synthesis of a circuit design is described. In one exemplary embodiment, preliminary routing information of nets in the circuit design is analyzed. The preliminary routing information includes track assignment information. Timing-critical nets are identified based on statistical distribution of the preliminary routing information of the nets. The identified timing-critical nets are assigned to a set of routing layers and removed from future net pattern matching. The remaining nets are clustered into multiple net patterns based on their physical attributes. The scaling factor for each net pattern is updated based on the scaling factor standard deviation and net length of the net pattern. Nets that are outside multiple standard deviations of a net pattern are assigned to routing layers. The scaling factors of the net patterns and the layer assignments are applied to the next phase of placement-based optimizations.

Claims20

Dependent claims

A method for improving physical synthesis of a circuit design, the method comprising:

performing an analysis for determining pattern-based scaling factors, wherein the performing of the analysis comprises:
combining attribute ranges of different physical attributes of nets to form net patterns, the nets including circuit elements and interconnections;
and
for each of the net patterns, computing a scaling factor to be included in net routing constraints, wherein the scaling factor is computed based on a relationship between a predicted route property and a post-route property, wherein the scaling factor is applied to a set of nets matching the net pattern during a next phase of placement-based optimizations;
analyzing, by a computer system, preliminary routing information of a plurality of nets in the circuit design;
identifying critical nets based on statistical distribution of the preliminary routing information of the plurality of nets;
assigning the identified critical nets to a set of routing layers;
and
removing the identified critical nets from the analysis for determining the pattern-based scaling factors;
and
adjusting the pattern-based scaling factors to provide a snapshot of a current state of a layout of the circuit.

8 more elements

A non-transitory computer-readable storage medium storing instructions thereon, the instructions when executed by a processor causing the processor to perform a method comprising the steps of:

performing an analysis for determining pattern-based scaling factors of a circuit design, wherein the performing of the analysis comprises:
combining attribute ranges of different physical attributes of nets to form net patterns, the nets including circuit elements and interconnections;
for each of the net patterns, computing a scaling factor to be included in net routing constraints, wherein the scaling factor is computed based on a predicted route property and a post-route property, wherein the scaling factor is applied to a set of nets matching the net pattern during a next phase of placement-based optimizations;
analyzing preliminary routing information of a plurality of nets in a circuit design;
identifying critical nets based on statistical distribution of the preliminary routing information of the plurality of nets;
assigning the identified critical nets to a set of routing layers;
removing the identified critical nets from the analysis for determining the pattern-based scaling factors;
and
adjusting the pattern-based scaling factors to provide a snapshot of a current state of a layout of the circuit design.

6 more elements

Dependencies are inferred from the claim text.

Generating pattern-based estimated RC data with analysis of route information

Life of this patent

Generating pattern-based estimated RC data with analysis of route information

Life of this patent

Abstract

Claims20