Add python script usage example.

boards/uniboard2c/designs/unb2c_test/revisions/unb2c_test_1GbE_I/tb_unb2c_test_1GbE_I.vhd

@@ -28,6 +28,7 @@
 -- > run 1 us.
 --
 -- Or try some MM:
+-- > as 12
 -- > run -a (or run 100 us)
 -- On command line do:
 -- > python $UPE_GEAR/peripherals/util_system_info.py --gn 0 -n 0 -v 5 --sim
@@ -37,7 +38,10 @@
 -- > run -a (or run 1 ms)
 -- > tc_unb2_test_eth_sim_start.sh
 -- > tc_unb2_test_eth_sim_stop.sh
-
+-- or use python script:
+-- . use -n 10000 packets/s to have 1 packet per BG sync interval of 100 us in sim
+-- > tc_unb2_test_eth.py --gn2 0 --stream 0 -n 10000 --dest loopback --range 1000,1001,1 --interval 100 --scheme tx --sim
+-- stop simulation.
 LIBRARY IEEE;
 USE IEEE.std_logic_1164.ALL;