clock_tb.sv

module clock_tb;
logic tc = 0;
logic [5:0] tsec = 6'd0;
logic [5:0] tmin = 6'd0;
logic [4:0] thour = 5'd0;

always #5e8 tc = ~tc;

Clock tb (
    .c(tc),
    .sec(tsec),
    .min(tmin),
    .hours(thour)
);

initial begin
    $finish();
end

endmodule