User guide

C-17
Simulation Options
+vpdignore
Tells VCS to ignore any $vcdplusxx system tasks and license
checking. By default, VCS checks out a VPD PLI license if there
is a $vcdplusxx system task in the Verilog source. In some
cases, this statement is never executed and VPD PLI license
checkout should be suppressed. The +vpdignore option
performs the license suppression.
+vpddrivers
Reports value changes for all drivers when there is more than one
driver. The driver values, for example, enable the Logic Browser
to identify which drivers produce an undesired X on the resolved
net. This option affects performance and memory usage for larger
designs or longer runs.
+vpdports
Causes VPD to store port information, which is then used by the
Hierarchy Browser to show whether a signal is a port and if so its
direction. This option to some extent affects simulation
initialization time and memory usage for larger designs.
+vpdnocompress
Disables the default compression of data as it is written to the
VPD file.
+vpdnostrengths
Disables the default storage of strength information on value
changes to the VPD file. Use of this option may lead to slight
improvements in VCS performance.
Options for Controlling $gr_waves System Task