R

Guided PAR

Example 4:

The following command runs PAR (using the Turns Engine) on all nodes listed in the allnodes file. It runs 10 place and route passes at placer effort level med and router effort level std on the mydesign.ncd file.

par –m allnodes –pl med –rl std –n 10 mydesign.ncd output.dir

Note: This command is not supported on Windows operating systems.

Guided PAR

When PAR runs using a guide design as input, PAR first places and routes any components and signals that fulfill the matching criteria from the guide file.

Optionally, PAR reads a previously placed and routed NCD file as a guide file to help in placing and routing the input design. This is useful if minor incremental changes have been made to create a new design. To increase productivity, you can use your last design iteration as a guide design for the next design iteration, as shown in the following figure:

First PAR Run

NCD

Input Design

PAR

NCD

Placed and Routed

Design

Second PAR Run

NCD

Modified Input Design

NCD

Guide File

PAR

NCD

New Placed and Routed

Design

X7202

Figure 9-2:Guided PAR for Design

Two command line options control guided PAR. The –gf option specifies the NCD guide file, and the –gm option determines whether exact or leverage or incremental mode is used to guide PAR.

The guide design is used as follows:

•If a component in the new design is constrained to the same location as a component placed in the guide file, then this component is defined as matching.

•If a component in the new design has the same name as a component in the guide design, that component matches the guide component.

•If a signal in the new design has the same name as a signal in the guide design, the signal matches the guide signal.

Development System Reference Guide

www.xilinx.com

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Xilinx 8.2i manual Guided PAR
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8.2i specifications

Xilinx 8.2i is a significant version of the Xilinx ISE (Integrated Software Environment) that emerged in the early 2000s, marking an important milestone in the world of FPGA (Field-Programmable Gate Array) development. This version introduced a slew of advanced features, technologies, and characteristics that made it an indispensable tool for engineers and developers in designing, simulating, and implementing digital circuits.

One of the standout features of Xilinx 8.2i is its enhanced design entry capabilities. This version supports multiple design entry methods, including schematic entry, VHDL, and Verilog HDL, giving engineers the flexibility to choose their preferred approach. The integrated environment provides user-friendly graphical interfaces, making it accessible for both novice and experienced users.

Xilinx 8.2i's synthesis tools have been improved to enable more efficient design compilation and optimization. The new algorithms used in this version facilitate faster synthesis times while reducing power consumption and improving performance. Furthermore, it features support for advanced FPGA architectures, which allows for the implementation of more complex designs with greater efficiency.

The implementation tools in Xilinx 8.2i include advanced place and route capabilities, utilizing state-of-the-art algorithms for optimized resource usage. These tools enable designers to make better use of FPGA resources, ensuring that designs fit within the constraints of the target device while maximizing performance.

Another key characteristic of Xilinx 8.2i is its extensive support for various Xilinx devices such as the Spartan, Virtex, and CoolRunner series. This compatibility ensures that developers can leverage the powerful features of these FPGA families, including high-speed transceivers and DSP slices.

Xilinx 8.2i also places a strong emphasis on simulation and verification. The version integrates with various simulation tools, allowing for thorough testing of the designs before implementation. This reduces the risk of errors and ensures that the final product meets specifications.

In addition, this version includes support for design constraints, enabling engineers to specify timing, area, and other critical design parameters. By accommodating constraints, Xilinx 8.2i helps in achieving reliable and efficient designs tailored to project needs.

In summary, Xilinx 8.2i is a robust software development tool that enhances the design process for FPGAs. Its comprehensive features, including multiple design entry options, advanced synthesis and implementation tools, extensive device support, and strong simulation capabilities, make it a valuable resource for engineers and developers striving for innovation in digital design.
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