$monitor(...)//$display(...)

$monitor($time,,,"wave=%b",wave);

reg[7:0] inner_port_tb_reg;
wire[7:0] inner_port_tb_wire;
reg[7:0] outer_port_tb_reg;
wire[7:0] outer_port_tb_wire;
reg out_en_tb;
integer i;

$display("\n **** time=%t ****",$time);
$display("OK! out_en=%d",out_en_tb);

$display("OK! outer_port_tb_wire=%d,inner_port_tb_wire=%d",
outer_port_tb_wire,inner_port_tb_wire);