Xilinx, Inc.

Cypress Semiconductor Corporation

Krishnan Anandh

Sudip K Nag

Jason Helge Anderson

Guenter Stenz

James L Saunders

Avijit Dutta

Neil Tuttle

Robert Douglas Thompson

Kamal Chaudhary

Haneef D Mohammed

Anirban Rahut

Sankaranarayanan Srinivasan

Andrew Price

Joseph P Skudlarek

Ryan Morse

Guenther Stenz

Steven Danz

Techniques for reducing post-routing delay variance are described herein. In an example embodiment, an initial netlist includes multiple instances that represent digital components of an electronic design. An base signature is assigned to each instance in the initial netlist, where the base signature is based on two or more design or connectivity attributes of the instance. The base signatures are then used to generate an initial instance ordering of the instances in the initial netlist. A subsequent netlist, different from the initial netlist but representing the same electronic design, is received. Base signatures are assigned to the instances on the subsequent netlist and a subsequent instance ordering is generated. The subsequent instance ordering preserves the same order as the initial instance ordering for those instances that are included in both the initial netlist and the subsequent netlist. In this manner, any later netlist-based processing (e.g., such as packing, placement, and routing) is shielded from the negative re-design effects caused by the subsequent changes to the initial netlist and, consequently, the post-routing timing delay variance of the electronic design is reduced.

Stability improvements for timing-driven place and route

Techniques for placement in highly constraint chip architectures are described herein. In an example embodiment, a computer system places a digital portion of an electronic design for a programmable chip. The programmable chip comprises multiple fixed-function blocks and a plurality of pins, where each one of the multiple fixed-function blocks can be coupled only to a respective subset of the plurality of pins. The electronic design comprises a particular fixed-function block (FFB) instance that is connected to a particular input-output (IO) instance. The computer system places (e.g., by using a backtracking search) the particular FFB instance on a particular fixed-function block and the particular IO instance on a particular pin from a particular subset of the plurality of pins, where in the programmable chip the particular fixed-function block can be coupled only to the particular subset of the plurality of pins.

Techniques for placement in highly constrained architectures

Method and apparatus are described for a placer system for placing design objects onto an arrayed architecture, such as a programmable logic device including an FPGA. More particularly, a placer interface is described for communicating with a placer core. The placer interface receives information from external entities, and unifies and generalizes this information for the placer core. The external entities comprise different representations of architecture, design, device, constraints and algorithm-dictated placer-movable objects.

Unified placer infrastructure

Within a computer automated tool, a method of physical circuit design can include assigning initial locations to components in the circuit design and determining an initial routing of connections between components in the circuit design using an overlap mode. The method also can include determining timing critical connections and selectively relocating components with at least one timing critical connection prior to performing a detailed routing of the circuit design.

Using router feedback for placement improvements for logic design

Method and apparatus for post-placement optimization of resources for connections is described. To optimize resource placement, search windows are generated responsive to driver and load components, as well as to a connection between the driver and load components. Adding in a straight-line path search window may be used as an alternative where a bypassed resource is to be relocated. Using connection-based optimization in combination with driver- and resource-based optimization results in improved optimization with negligible impact on runtime.

Relocation of components for post-placement optimization

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San Jose, CA, United States of America

Krishnan Anandh