Xilinx 8.2i manual IBISWriter Input Files, IBISWriter Output Files, IBISWriter Options

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IBISWriter Input Files

IBISWriter Input Files

IBISWriter requires a design source file as input.

•FPGA Designs

Requires a physical description of the design in the form of an NCD file with a .ncd file extension.

•CPLD Designs

The input is produced by CPLDfit and has a .pnx file extension.

IBISWriter Output Files

IBISWriter outputs an .ibs ASCII 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. The format of the IBIS output file is determined by the IBIS standard. The output file must be able to be validated by the Golden Parser to ensure that the file format conforms to the specification.

Note: IBISWriter gives an error message if a pin with an I/O Standard for which no buffer is available is encountered, or if a DCI value property is found for which no buffer model is available. After an error message appears, IBISWriter continues through the entire design, listing any other errors if and when they occur, then exiting without creating the .ibs output file. This error reporting helps users to identify problems and make corrections before running the program again.

IBISWriter Options

This section provides information on IBISWriter command line options.

–allmodels (Include all available buffer models for this architecture)

To reduce the size of the output .ibs file, IBISWriter produces an output file that contains only design-specific buffer models, as determined from the active pin list. For users who wish to access all available buffer models, the –allmodels command line option should be used.

Use the following syntax when using the –allmodels option:

ibiswriter –allmodels infile outfile.ibs

–g (Set Reference Voltage)

The –g command line option varies by architecture as shown in Table 17-1.

Use the following syntax when using the –g option:

ibiswriter –goption_value_pair infile outfile.ibs

The following is an example using the VCCIO:LVTTL option value pair.

ibiswriter –g VCCIO:LVTTL design.ncd design.ibs

The –g option supports only the architectures listed in the following table:

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