Download SIMetrix User`s Manual

Simulator Reference Manual
vsxd.vpi is able to respond to events during the Verilog simulation that cause a change
on an output port and send those changes to the SIMetrix simulator.
Conversely the SIMetrix simulator detects when there are changes on an input port and
notifies vsxd.vpi which then notifies the Verilog simulator.
vsxd.vpi is also able to enumerate the ports and parameters of a Verilog module and
report this information back to SIMetrix. This process is performed before a simulation
starts in order to build the final Verilog top level design.
Interface Configuration
In order for the interface to be setup, SIMetrix needs to know how to drive the Verilog
simulator. Also the Verilog simulator needs to know about vsxd.vpi.
The interface is configured by the VerilogHDL.ini file which is located in the support
folder under windows or in /usr/local/simetrix_nn/share under Linux. VerilogHDL.ini
uses the standard inifile format. Each supported simulator is defined in a section within
VerilgHDL.ini and the section must at a minimum define the following keys ‘Name’,
‘Script’ and ‘Path’. ‘Name’ defines a display name for the simulator that will be
meaningful to the user. ‘Script’ defines a script name that is used to launch the Verilog
simulator. (More on the launch script below). ‘Path’ is passed to the launch script and
would usually be the path where the main binary executable for the Verilog simulator
is located.
Launch Script
The launch script is a SIMetrix script that is called by SIMetrix. It is responsible for
starting the Verilog process usually via the ‘Shell’ function. The launch script knows
about the command line syntax for the Verilog simulator.
For more details about the launch script, see the script used to launch the GPL cver
simulator.
Verilog Simulation Preparation
SIMetrix netlists can instantiate any number of verilog designs, both multiple instances
of the same Verilog module and multiple module designs. In order for the Verilog
simulator to be able to handle these multiple instances, it needs to be presented with a
top level module that defines the interconnections between them. This top level
module is generated automatically by SIMetrix on each simulation run and is called
(by default) vsx_root.v.
364