simulation parent directory. 
----------------------------
The directory structure is organised as follows.
1. tb -> The testbench code is kept in this directory.
2. vcd -> vcd dump is redirected here.
3. run -> ModelSim tool run directory.
	  ModelSim scripts (do files).

How to run Simulation manually
------------------------------
1. "./run/simulate.do" is the main script called in modelsim.
   edit the library files and testbench path in simulate.do
   if needed, edit the vcd generation directory and name.
2. "./run/run_sim.bash" is the run script

  
