R

BitGen Options

Compress

This option uses the multiple frame write feature in the bitstream to reduce the size of the bitstream, not just the .bit file. Using the Compress option does not guarantee that the size of the bitstream will shrink. Compression is enabled by setting the BitGen option –g compress; compression is disabled by not setting it.

Note that the partial bit files generated with the BitGen –rsetting automatically make use of the multiple frame write feature, and are compressed bitstreams.

Architectures:

Virtex, Virtex-E, Virtex-II, Virtex-II Pro, Spartan-

 

II, Spartan-IIE, Virtex-4, Spartan-3

Settings:

None

Default:

Off

ConfigRate

Virtex/-E/-II/-II Pro and Spartan-II/-IIE/-3 use an internal oscillator to generate the configuration clock, CCLK, when configuring in a master mode. Use the configuration rate option to select the rate for this clock.

Architectures:

Virtex, Virtex-E, Virtex-II, Virtex-II Pro, Virtex-4,

 

Spartan-II, Spartan-IIE, Spartan 3, Spartan-3E

Settings

4, 5, 7, 8, 9, 10, 13, 15, 20, 26, 30, 34, 41, 45, 51, 55, 60

Default:

4

Settings for

6, 3, 12, 25, 50, 100 (default is 6)

Spartan-3/-3E

 

Default for

6

Spartan-3:

 

Note: For a list of specific architecture settings, use the bitgen -h [architecture] command.The default value may vary by architecture.

CRC

The CRC option controls the generation of a Cyclic Redundancy Check value in the bitstream. When enabled, a unique CRC value is calculated based on bitstream contents. If the calculated CRC value does not match the CRC value in the bitstream, the device will fail to configure. When CRC is disabled a constant value is inserted in the bitstream in place of the CRC and the device will not calculate a CRC.

Architectures:

Virtex-II, Virtex-II Pro, Virtex-4, Spartan-3,

 

Spartan-3E

Settings:

Disable, Enable

Default:

Enable

Development System Reference Guide

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Xilinx 8.2i manual Compress, ConfigRate
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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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