Answers Database

XDE issues messages on non-applicable TNM and Timespecs


Record #1576

Product Family:  Software

Product Line:  FPGA Core

Problem Title:
XDE issues messages on non-applicable TNM and Timespecs


Problem Description:
After manually editing an LCA in the Xact Design Editor
(XDE), XDE issues messages in regards to invalid Timespecs,
TNMs, or Timegroups when the modifed LCA is loaded into
XDE.  The following are sample messages which might be
encountered:

OUT: not a FF output net.
OUT2: not a FF output net.

This can happen if elements which were marked with the TNMs
or Timegroup for place and route are manually edited in XDE
so they are no longer valid Timespec endpoints.  In the
above example, two flip flops which sourced the nets OUT
and OUT2 were modifed into combinational logic.


Solution 1:

The messages issued are harmless and can be ignored.

Although not recommended, you can manually edit the LCA
file in a text editor and delete the associated Timespec
references to eliminate the messages.

Warning: if not done properly, information required for
Xdelay-Timespec analysis could be lost.

The records for TNM or Timegroup appear in an LCA in the
following format:
System Xdelay Timegroup <NAME> -<TYPE> <NET1> <NET2> ...

The modification required to eliminate the messages is
to delete the associated signal name from the Timegroup
record.  In the above example (see Problem Descriptioin),
the Timegroup record was:

System Xdelay Timegroup BOB -FF OUT OUT1 OUT2 OUT3

Modifying the record to the following eliminates the
messages:

System Xdelay Timegroup BOB -FF OUT1 OUT3



End of Record #1576