User guide

C-3
Simulation Options
+ntb_enable_solver_trace=value
Enables a debug mode that displays diagnostics when VCS
executes a randomize() method call. Allowed values are:
0 - Do not display (default).
1 - Displays the constraints VCS is solving.
2 - Displays the entire constraint set.
+ntb_enable_solver_trace_on_failure[=value]
Enables a mode that displays trace information only when the
VCS constraint solver fails to compute a solution, usually due to
inconsistent constraints. When the value of the option is 2, the
analysis narrows down to the smallest set of inconsistent
constraints, thus aiding the debugging process. Allowed values
are 0, 1, and 2. The default value is 2.
+ntb_exit_on_error[=value]
Causes VCS to exit when value is less than 0. The value can be:
0 - continue
1 - exit on first error (default value)
N - exit on nth error.
When the value is 0, the simulation finishes regardless of the
number of errors.
+ntb_load=path_name_to_libtb.so
Specifies loading the testbench shared object file libtb.so.
+ntb_random_seed=value
Sets the seed value to be used by the top level random number
generator at the start of simulation. The random(seed) system
function call overrides this setting. The value can be any integer
number.