Patent · US Expired

Netlist resynthesis program based on physical delay calculation

US6557144B1 · kind B1 · utility

10Cited by
11References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 14, 2000
Grant dateApr 29, 2003
Priority date
Expiry dateJul 25, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F30/392
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A computer program that improves a netlist of logic nodes and physical placement for an IC. The program (a) identifies critical nodes based on delay information calculated from the physical placement. Then the program (b) selects a set of critical nodes and optimally collapses their critical fan-ins and part of the non-critical fan-ins based on their Boolean relationship, which, includes at least one critical node. After that, the program (c) remaps the collapsed sub-netlist by covering its subject graph with an optimal pattern graph, and dynamically estimates and updates the fanout loads. The program returns to step (b) if the remapped sub-netlist is unacceptable, and returns to step (a) after updating the delay information and coordinates of newly mapped gates if the remapped sub-netlist is acceptable. The program exits at step (a) when no more critical nodes are identified at step (a).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.