Spartan6引脚分配问题

你好，
我有一个我无法理解的引脚分配问题。
我使用PlanAhead13.2来创建引脚分配，然后使用UCF文件为XC6SLX45-2CSG324C。
假设存储体1和3不能用作差分输出，我将差分输入和输出连接到存储体0，将DDR接口连接到存储体3，将并行引导NOR闪存连接到存储体1和2（因为它具有专用引脚
两个银行），然后我继续将另一部分LVDS信号连接到bank 2.我已成功连接输出对，但堆叠了输出对的连接。
当我将输出对拖到第2行时，我收到一个弹出式按摩，这意味着“无法放置任何端口。请尝试顺序放置以获得更详细的原因。”
我注意到如果将输出对拖到bank 0，就可以了......但是我需要将它连接到bank 2.任何人都有想法？
谢谢，
安德烈



以下为原文

Hello,

I have a pin assignment problem that i can not understand. I do use PlanAhead13.2 in order to create pin assignment and then UCF file for XC6SLX45-2CSG324C. Assuming that bank 1 and 3 cannot be used as a differential output I have connected differential inputs and outputs to bank 0, connected a DDR interface to bank 3, connected a parallel boot NOR flash to bank 1 and 2(as it has dedicated pins on both banks), then I proceeded with connection of another portion of LVDS signals to bank 2. I have succeeded with connection of output pairs, but stacked with connection of output pairs. I receiving a pop up massage when I drag an output pair to bank 2 which means "Can not place any port. Try a sequential placement for a more detailed reason." I noticed if a drag the output pair to bank 0, it is OK...However I need to connect it to bank 2. Anyone have an idea?

Thanks,
Andrey