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Chapter 17

IBISWriter

The IBISWriter program is compatible with the following families:

•Virtex™, Virtex™-E

•Virtex™-II

•Virtex™-II Pro, Virtex™-II Pro X

•Virtex™-4

•Virtex™-5 LX

•Spartan™-II, Spartan™-IIE

•Spartan™-3, Spartan™-3E, Spartan™-3L

•CoolRunner™ XPLA3, CoolRunner™-II

•XC9500™, XC9500XL™, XC9500XV™

This chapter describes the IBISWriter program. This chapter contains the following sections:

•“IBISWriter Overview”

•“IBISWriter Syntax”

•“IBISWriter Input Files”

•“IBISWriter Output Files”

•“IBISWriter Options”

IBISWriter Overview

The Input/Output Buffer Information Specification (IBIS) is a device modeling standard. IBIS allows for the development of behavioral models used to describe the signal behavior of device interconnects. These models preserve proprietary circuit information, unlike structural models such as those generated from SPICE (Simulation Program with Integrated Circuit Emphasis) simulations. IBIS buffer models are based on V/I curve data produced either by measurement or by circuit simulation.

IBIS models are constructed for each IOB standard, and an IBIS file is a collection of IBIS models for all I/O standards in the device. An IBIS file also contains a list of the used pins on a device that are bonded to IOBs configured to support a particular I/O standard (which associates the pins with a particular IBIS buffer model).

IBISWriter supports the use of digitally controlled impedance (DCI) for Virtex-II input designs with reference resistance that is selected by the user. Although it is not feasible to have IBIS models available for every possible user input, IBIS models are available for I/O Standards LVCMOS15 through LVCMOS33 for impedances of 40 and 65 ohms, in addition

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Xilinx 8.2i manual IBISWriter Overview
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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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