IBISWriter Syntax

Chapter 17: IBISWriter

to the 50 ohms impedance assumed by XCITE standards. If not specified, the default impedance value is 50 ohms.

The IBIS standard specifies the format of the output information file, which contains a file header section and a component description section. The Golden Parser has been developed by the IBIS Open Forum Group (http://www.eigroup.org/ibis) to validate the resulting IBIS model file by verifying that the syntax conforms to the IBIS data format.

The IBISWriter tool requires a design source file as input. For FPGA designs, this is a physical description of the design in the form of an NCD (native circuit description) file with a .ncd file extension. For CPLD designs, the input is produced by CPLDfit and has a

.pnx file extension.

IBISWriter outputs a .ibs file. This file comprises a list of pins used by your design; the signals internal to the device that connect to those pins; and the IBIS buffer models for the IOBs connected to the pins.

Note: Virtex-II Pro architecture does not include the multi-gigabit transceiver (MGT). There are no IBIS models available for these IOBs.

To see an example of an IBIS file, refer to Virtex Tech Topic VTT004 at the following web location: http://www.xilinx.com/products/virtex/techtopic/vtt004.pdf

The following figure shows the IBISWriter flow:

NCDPNX

IBISWriter

IBS

X9553

Figure 17-1:IBISWriter Flow

Use the following syntax to run IBISWriter from the command line:

ibiswriter [options] infile outfile[.ibs]

options is one or more of the options listed in “IBISWriter Options”.

infile is the design source file for the specified design. For FPGA designs, infile must have a

.ncd extension. For CPLD designs, infile is produced by the CPLDfit and must have a .pnx extension.

outfile[.ibs] is the destination for the design specific IBIS file. The .ibs extension is optional. The length of the IBIS file name, including the .ibs extension, cannot exceed 24 characters.

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Development System Reference Guide

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.

Xilinx 8.2i manual IBISWriter Syntax, Ibiswriter options infile outfile.ibs

Models: 8.2i

Chapter 17: IBISWriter

Figure 17-1:IBISWriter Flow