Add python example to check BG gapsize.

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

@@ -31,7 +31,7 @@
 -- > 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
---
+-- > python $UPE_GEAR/peripherals/pi_diag_block_gen_reg.py --gn 0 -s ETH_0 --reg gapsize=199999000
 
 LIBRARY IEEE;
 USE IEEE.std_logic_1164.ALL;