管脚三态问题

只看该作者 · 2012-12-9 19:14

QUARTUS编译产生如下警告：
Warning (18029): Output pin "_subnet_pin_115" driven by bidirectional pin "sram_bus[10]" cannot be tri-stated.
有以下帮助是这么说的：

CAUSE:	The specified output pin is driven by both the specified bidirectional pin and tri-stated logic. However, the current device does not support a tri-stated output pin. When the output pin is not driven by either the logic or the bidirectional pin, its output value is undefined.
ACTION:	If the output pin is always driven by either the logic or the bidirectional pin, no action is required. Otherwise, insert an extra tri-state buffer before the output pin.

意思是说目前的器件不支持三态输出管脚。出现警告是不是会影响管脚输出呢？因为现在对SRAM读写数据出现了问题，我想知道shibus