小弟要写个系统,其中需要实现三态门,仿真顺利通过,但QuartusII综合时得到如下的warning:Tri-state node(s) do not directly drive top-level pin(s)。F1帮助后的Action:Avoid this warning by either removing the non-tri-state fan-outs of the affected tri-state nodes or replacing the tri-state nodes with non-tri-state logic.这个Action小弟不知如何使用,望哪位大牛大虾能给个解释。