We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 6173

5.1i Timing - Command "lca2xnf -s" is no longer available. What should I use instead?


General Description:

In the XACT tools, the "lca2xnf -s" command wrote a file that contained the timing parameters for a specific design. This command is no longer available for M1.5. What should I use instead?


For M1.5 and newer versions, replace "lca2xnf -s" with the "SPEEDPRINT -s" command.

The "SPEEDPRINT" executable prints the timing parameters found in a specific speed file. It is independent of the design, and this design independence is the main difference between the "SPEEDPRINT" and "lca2xnf -s" commands.

The command that should be used in current software versions is:

speedprint xc4005xl -s 09

Be aware that the one difference between "lca2xnf -s" and "SPEEDPRINT" is that "lca2xnf -s" tried to create a data sheet for the speed grade used by a design. "SPEEDPRINT" focuses on printing the delays in the speed file and does not present them as a data sheet.

The "lca2xnf -s" command did some rounding and grouping of numbers in the speed file before printing a data sheet; "SPEEDPRINT" does not do this. Instead, "SPEEDPRINT" accurately reports exactly what numbers are going to be used by PAR and TRCE. (It will not exactly match the data sheet.)

For more information, please also see (Xilinx Answer 6067).

AR# 6173
Date Created 08/31/2007
Last Updated 01/18/2010
Status Archive
Type General Article