Chapter 6: NGDBuild

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–aul (Allow Unmatched LOCs)

By default (without the –aul option), NGDBuild generates an error if the constraints specified for pin, net, or instance names in the UCF or NCF file cannot be found in the design. If this error occurs, an NGD file is not written. If you enter the –aul option, NGDBuild generates a warning instead of an error for LOC constraints and writes an NGD file.

You may want to run NGDBuild with the –aul option if your constraints file includes location constraints for pin, net, or instance names that have not yet been defined in the HDL or schematic. This allows you to maintain one version of your constraints files for both partially complete and final designs.

Note: When using this option, make sure you do not have misspelled net or instance names in your design. Misspelled names may cause inaccurate placing and routing.

–bm (Specify BMM Files)

-bmfile_name [.bmm]

The –bm option specifies a switch for the .bmm files. If the file extension is missing, a .bmm file extension is assumed. If this option is unspecified, the ELF or MEM root file name with a .bmm extension is assumed. If only this option is given, then Ngdbuild verifies that the

.bmm file is syntactically correct and makes sure that the instances specified in the .bmm file exist in the design. Only one –bm option can be used

–dd (Destination Directory)

–ddNGOoutput_directory

The –dd option specifies the directory for intermediate files (design NGO files and netlist files). If the –dd option is not specified, files are placed in the current directory.

–f (Execute Commands File)

–fcommand_file

The –f option executes the command line arguments in the specified command_file. For more information on the –f option, see “–f (Execute Commands File)” in Chapter 1.

–i (Ignore UCF File)

By default (without the –i option), NGDBuild reads the constraints in the UCF file automatically if the UCF file in the top-level design netlist directory has the same base name as the input design file and a .ucf extension. The –i option ignores the UCF file.

Note: If you use this option, do not use the –uc option.

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Xilinx 8.2i manual Aul Allow Unmatched LOCs, Bm Specify BMM Files, Dd Destination Directory, Ignore UCF File
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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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