Xilinx Synthesis Technology User Guide

XST User Guide
Launching XST
This file is generated in the current output directory (see the
-ofn option).
• RTL netlist for RTL viewer (.ngr)
• Synthesis LOG file (.srp)
• Temporary files
Temporary files are generated in the XST temp directory. By
default the XST temp directory is /tmp on workstations and the
directory specified by either the TEMP or TMP environment
variables under Windows. The XST temp directory can be
changed using the set -tmpdir directive.
• VHDL compilation files
Note There are no compilation files for Verilog.
VHDL compilation files are generated in the VHDL dump
directory. The default dump directory is the “xst” subdirectory of
the current directory.
Note It is strongly suggested that you clean the XST temp directory
regularly because the directory contains the files resulting from the
compilation of all VHDL files during all XST sessions. Eventually the
number of files stored in the VHDL dump directory may severely
impact CPU performances. This directory is not automatically
cleaned by XST.
You can run XST in two ways.
• XST Shell—You can type xst to enter directly into an XST shell.
You enter your commands and execute them. In fact, in order to
run synthesis you have to specify a complete command with all
required options before running. XST does not accept a mode
where you can first enter set option_1, then set option_2, and then
enter run.
All the options must be set up at once. Therefore, this method is
very cumbersome and Xilinx suggests the use of the next
described method.
8-2 Xilinx Development System