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Method of Concurrent Routing and Port Assignment

IP.com Disclosure Number: IPCOM000201548D
Publication Date: 2010-Nov-15
Document File: 4 page(s) / 137K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system is provided to incrementally route Random Logic Macro (RLM) pins based on port constraints. The port constraints include shape fixed layer fixed, and location fixed. Based on the constraints on the RLM pin, the shape of the port, the layer of the port, or the location of the port may be changed during routing.

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Method of Concurrent Routing and Port Assignment

Disclosed is a method and system for incrementally routing Random Logic Macro (RLM) pins based on port constraints.

Figs. 1a-1c illustrate a flowchart depicting the method of incrementally routing RLM pins based on port constraints. The port constraints include "shape fixed", "layer fixed", and "location fixed". Default values corresponding to the port constraints may be set as false, thereby allowing a router to assign ports dynamically during routing. However, if an RLM pin is in a critical path, the values corresponding to each of the port constraints may be set as true.

Initially, the router identifies unrouted RLM pins and creates a list of the unrouted RLM pins. The router then determines if the constraint "shape fixed" for each RLM pin is set. If the shape of an RLM pin is not fixed the router decreases the size of the RLM pin based on the constraints on the size and shape of the RLM pin. Alternatively, the router changes the shape of the RLM pin to prevent overlaps with routing blockages. This may be done by considering the wiring blockage both inside and outside the RLM pin. The router then performs an incremental routing on nets connected to the RLM pin whose shape has been modified. The router then checks for RLM pins that are yet not routable and subsequently updates the list of unrouted RLM pins. The method of incrementally routing RLM pins if the shape of the RLM pin is not fixed is depicted in the flowchart illustrated in Fig. 1a.

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Figure 1a


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Figure 1b

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Figure 1c

Thereafter, for each of the unrouted RLM pins, the router determines if the constraint "layer fixed" is set. If there is no constraint on the layer, the router reassigns the RLM pins to a layer without routing blockages around the RLM pin on that layer. This may be done by considering the wiring blockage both inside and outside the RLM pin. Additionally, a constraint may be provided to the router for the possible layers it can chose for reassigning the RLM pins. The router then reassigns the...