vsim - The vsim command invokes the VSIM simulator


 -L <library_name> …

(optional) Specifies the library to search for design units instantiated from Verilog and for VHDL default component binding. If multiple libraries are specified, each must be preceded by the -L option. 


-t [<multiplier>]<time_unit>
(optional) Specifies the simulator time resolution. <time_unit> must be one of the following: 
fs, ps, ns, us, ms, sec
The default is 1ns; the optional <multiplier> may be 1, 10 or 100.

Note that there is no space between the multiplier and the unit (for example, 10fs, not 10 fs).



keep data for debuging assertion failures.



(optional) Instructs Questa SIM to generate a database of connectivity information to be used for post-sim debug in the Dataflow and Schematic windows. The database pathname should have a .dbg extension. If a database pathname is not specified, Questa SIM creates a database file named vsim.dbg in the current directory. 

An existing .dbg file will be reused and a note printed to the transcript when the -debugdb switch is specified and your design has not changed since the database was created.


# compile testbench file

vcom -93 -explicit -work work $srcpath_0/tb_xxx.vhd

# run simulation

vsim -L xxx -t 1ps tb_xxx