User guide

13-11
SDF Backannotation
For example, the SDF annotation of module paths contained within
the hierarchy of a module named myasic requires a PLI table such
as this:
$sdf_annotate call=sdf_annotate_call acc+=mp,prx:myasic+
If possible, take advantage of the %CELL wildcard scope to add the
needed ACC capabilities to library cells only, which are often the only
cells requiring SDF annotation:
$sdf_annotate call=sdf_annotate_call acc+=mp, prx:%CELL
For methodologies requiring delay annotation in the sub-hierarchy of
cells, use:
$sdf_annotate call=sdf_annotate_call acc+=mp, prx:%CELL+
When running vcs use the -P compile-time option to specify this PLI
table, as you would to specify any user task or function implemented
in a custom PLI application. You do not need to provide the function
sdf_annotate_call as it is part of the VCS product by default.
% vcs -P sdf.myasic.tab myasic.v +oldsdf
Example 13-2 Reading the ASCII SDF File Example
The following Verilog model, in source file ex2.v, contains a
specparam in its specify block:
‘timescale 1 ns / 1 ns
module top;
reg in;
leaf leaf1(in,out);
initial begin
$sdf_annotate(“ex2.sdf”,top);
$monitor($time,,in,,out);
in = 0;
#100 $finish;