How to retrieve a value from simulator in specman

Question

I am trying to access a simulator configuration parameter run_mode this value is stored as a BRUN variable. I am using the following code to access the parameter in specman.

simulator_command("sn $env(BRUN_RUN_MODE)")

However what is returned (eg: interactive_debug) is interpreted as an specman command which obviously doesn't exist. Is there a way to send this parameter back to specman?

Answer 1

Please try

var run_mode := get_symbol("BRUN_RUN_MODE");

Answer 2

simulator_command attempts to interact with the CLI of the simulator. i.e. the verilog/vhdl simulator TCL CLI. What you're doing there is going into the simulator's CLI and then calling back into specman with the sn [...] command while using TCL's $env to grab the environment variable. Something like this call diagram:

Assuming BRUN_MODE is set to FOO

Specman Runtime              Verilog/VHDL CLI 
   |                               *
   | --> simulator_command( ------>|
   *                               |
   *                          sn $env(BRUN_RUN_MODE)
   *                               |  (TCL interpreter string transform)
   *                               v
   *                            sn "FOO"
   *                               |
   |<-------- "FOO" <--------------|
   |                               *
   |------->(end of `sn` call) --->|
   *                               |
   |<--(end of simulator_command)--|
   |                               *

You want to use get_symbol as Thorsten answered, unless you really do want a simulator command and not an environment variable. In which case, calling simulator_command and then extracting the output from your simulator may be appropriate. However, that would require looking at your specific simulators documentation which is separate from your Specman documentation.