GLOBAL_SIM_BASE_CLK clk reset b
0 0 1 0X0 
0 1 1 0X0
0 0 0 0X0
0 1 0 0X0
0 0 0 0X1
0 1 0 0X1
0 0 0 0X2
0 1 0 0X2
0 0 0 0X3
0 1 0 0X3
