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# 15342

9.1i PrimeTime/NetGen - PrimeTime reports an error when I use the "read_sdc" command to read constraints


I am trying to create a report from PrimeTime, and the following error occurs when I use the "read_sdc" command:

"Error: unknown command 'remove_from_collection' (CMD-005)

Information: script 'constraints.sdc' stopped due to error (CMD-081)

Error: Errors reading SDC file: Here is the constraint :-

set_input_delay 0 -clock "clk" [remove_from_collection [all_inputs] [get_ports {clk}]]"

This error is not reported when I put all of the constraints in a script file.


This problem occurs because the xilinx2primetime tool creates non-SDC constructs such as "remove_from_collection."

The "set_input_delay" command is an SDC command. However, "read_sdc" does not recognize the meaning of "remove_from_collection" in the following line:

set_input_delay 0 -clock "clk" [remove_from_collection [all_inputs] [get_ports {clk}]]

The command above is not written in true SDC-compatible syntax. The "remove_from_collection" command is a specific Tcl function that can be executed in PrimeTime (outside of read_sdc). PrimeTime recognizes the "remove_from_collection" function. If you use "write_sdc" with PrimeTime, you will not see "remove_from_collection" in the file. To read the SDC file from xilinx2primetime, Xilinx recommends that you source the SDC file.

Ideally, xilinx2primetime should build the list that results from the following, and then apply the "set_input_delay" to it:

remove_from_collection [all_inputs] [get_ports {clk}]

You can use PrimeTime case analysis to propagate the proper clock through BUFGMUX by setting the select line to the appropriate value.

AR# 15342
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article