R

BitGen Options

–l (Create a Logic Allocation File)

This option creates an ASCII logic allocation file (design.ll) for the selected design. The logic allocation file shows the bitstream position of latches, flip-flops, IOB inputs and outputs, and the bitstream position of LUT programming and Block RAMs.

In some applications, you may want to observe the contents of the FPGA internal registers at different times. The file created by the –l option helps you identify which bits in the current bitstream represent outputs of flip-flops and latches. Bits are referenced by frame and bit number within the frame.

The iMPACT tool uses the design.ll file to locate signal values inside a readback bitstream.

–m (Generate a Mask File)

Creates a mask file. This file determines which bits in the bitstream should be compared to readback data for verification purposes.

–r (Create a Partial Bit File)

–rbit_file

The –r option is used to create a partial bit file. It takes that bit file and compares it to the

.ncd file given to bitgen. Instead of writing out a full bit file, it only writes out the part of the bit file that is different from the original bit file given.

–w (Overwrite Existing Output File)

Enables you to overwrite an existing BitGen output file. See “BitGen Output Files” for additional information.

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Xilinx 8.2i manual Create a Logic Allocation File, Generate a Mask File, Create a Partial Bit File, Rbitfile

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.