Route Fix Guidance for IC Routing Violations

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Solution Overview

Problem

Existing routing systems for integrated circuits often ignore design rules to improve performance, leading to design rule violations that require post-routing fixes, which can be inefficient and ambiguous, as they lack clear guidance on how to modify the routing solution to avoid violations.

Innovation Solution

A system generates route fix guidance that includes metal avoidance areas, specified as rectangles, to help the router locally modify the routing solution by removing or adding rectangles and moving vias, ensuring that the design rule violations are addressed without introducing new violations, by iteratively using multiple metal avoidance areas if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the router is made aware of all design rules to generate violation-free netlists, then the routing solution quality improves, but the routing process speed deteriorates substantially due to computationally intensive lithography models

Engineering Contradiction:

Improverouting solution qualityVSAvoidrouting process speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The routing process is divided into two distinct phases: (1) a fast routing phase that ignores computationally intensive design rules to generate an initial routing solution quickly, and (2) a post-routing fix phase that addresses only the specific design rule violations identified. This segmentation allows the router to achieve acceptable routing speed while still producing violation-free final solutions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs preliminary routing without considering all design rules, generating an initial routing solution that may contain violations. This preliminary action enables fast routing, and subsequent post-routing processing then fixes the violations that were tolerated during the initial phase.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If design rule violations are ignored during routing to improve performance, then the routing process speed improves, but the number of design rule violations increases, requiring additional post-routing fixes

Engineering Contradiction:

Improverouting process speedVSAvoiddesign rule compliance

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system implements a feedback mechanism where the post-routing process identifies design rule violations in the initial routing solution and generates targeted route fix guidances. These guidances are fed back to the router, which then performs local modifications to eliminate the violations. This feedback loop ensures that violations are systematically addressed without requiring the router to consider all rules during the initial fast routing phase.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If local modifications are made to fix design rule violations after routing, then the routing solution can be corrected, but the convergence time increases due to iterative fixing processes

Engineering Contradiction:

Improvedesign rule complianceVSAvoidconvergence time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system extracts and isolates only the specific design rule violations from the complete set of design rules. Instead of re-evaluating all design rules during post-processing, the system identifies and addresses only the violated rules through targeted route fix guidances. This extraction approach minimizes the computational effort required for fixing violations and reduces overall convergence time.

Inventive Principle:

Principle #2Taking out (Extraction)

4Adaptability or versatility

If multiple metal avoidance areas are provided in route fix guidance to give the router options, then the ability to fix violations improves, but the complexity of processing the guidance increases

Engineering Contradiction:

Improveviolation fixing capabilityVSAvoidguidance processing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system provides the router with multiple dynamic options for fixing violations through route fix guidances that include multiple metal avoidance areas. The router can adaptively select from these options based on the current routing state and constraints. This dynamic approach enhances violation fixing capability while allowing the router to manage complexity by choosing appropriate fixes rather than processing all options equally.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8527930B2Generating and using route fix guidance

Publication Date: 2013.09.03 SYNOPSYS INC

AI summary

Some embodiments of the present invention provide systems for generating and using a route fix guidance for fixing design rule violations. A route fix guidance includes information that enables a router to locally modify a routing solution to fix one or more design rule violations. A route fix guidance can include a set of two or more metal avoidance areas, wherein avoiding any one of the set of two or more metal avoidance areas during routing fixes the design rule violation. Additionally, a route fix guidance can specify a set of rectangles to remove from a routing solution, and a set of rectangles to insert into or add to a routing solution. Further, the route fix guidance can include information for moving one or more vias to new locations in the routing solution. The route fix guidance can specify a sequence in which the local modifications are to be made.