Answers Database

Viewsim:ERROR:Multiple conflicting floatval attributes


Record #251

Product Family:  Software

Product Line:  ViewLogic

Problem Title:
Viewsim:ERROR:Multiple conflicting floatval attributes


Problem Description:
Typical delays in use.
All delays scaled by 1.
(design_name.vsm,704): ERROR: Multiple conflicting floatval attributes on net
TOP\START. Net floated to 0.

Viewlogic will issue a error (one that does not stop the simulation) whenever
it finds conflicting floatval attributes on a net.  The floatval or float
value is used to define a default voltage level if a signal is not driven.
You can put a float value on any signal; Xilinx primitives have floatvals on
some of the DFF control pins.
The CE pin has a floatval of "1", so if this signal is not connected the DFF
will simulate with the CE enabled.  Conversely the RD pin has a floatval of
"0" so that it will simulate with the reset not enabled.  These floatvals are
only used for simulation and do not appear in the XNF or LCA files.  If you
have added floatvals or connect signals up in such a way as to drive both the
CE of some DFF's and the RD of other DFF's then you will always get a warning:

(design_name.vsm,704): ERROR: Multiple conflicting floatval attributes on net
TOP\START. Net floated to 0.


Solution 1:

You can ignore this warning if the source of the net is NOT a 3-state buffer.
If it is a 3-state buffer and the floatval chosen is the one you want you can
also ignore this error.  If it is not the value you want you may override
this floatval by forcing the net and then releasing it.  The floatval is not
restored after the net is released.  (This is a "behavior" or "feature" of
VIEWSIM and may not always retain this behavior in future releases.)




End of Record #251