ERROR:Pack:1107 - Unable to combine the following symbols into a single IOB

大家好，最近我在写一个数据储存的VHDL代码，当我再给一个时钟管脚分配位置时，出现如下错误，弄了好半天也没弄明白，希望路过的高手能指点指点，谢谢啦！
ERRORack:1107 - Unable to combine the following symbols into a single IOB
   component:
    PAD symbol "fosc_j" (Pad Signal = fosc_j)
    BUF symbol "fosc_j_IBUF" (Output Signal = fosc_j_IBUF)
   Each of the following constraints specifies an illegal physical site for a
   component of type IOB:
    Symbol "fosc_j" (LOC=P15)
   Please correct the constraints accordingly.

时钟管脚，应该对应相应BANK里的专用时钟IOB吧?LZ是不是赋给普通的数据IOB了，
并且如果你是单端信号，最好给差分管脚的P端，

2# eaglelsb
呵呵，我是赋给时钟管脚的啊，且片上所有时钟管脚我都试过，都一直出现这问题，很是让人郁闷啊！

可能是差分信号没有使用IBUFDS或IBUFGDS的原因

同问！

发你的UCF和代码中声明这个信号和第一次使用这个信号的代码来看看

6# falloutmx
呵呵，这个问题解决了，在时钟信号输入端假如哥缓冲就行了，不知道为什么加缓冲器就行了，能解释解释么

你是不是时钟进来给DCM了?

ISE里有个IOB的选项，我估计选了这个你就可以不插入BUF了

我最近也遇到了这个问题，时钟信号是从Bank114差分引进来的，我用的是IBUFDS变为了单端，出现了这个错误，小编具体是怎么解决的啊?

求解啊

这个顶一下，我现在也遇到这样的问题，希望小编不吝赐教！

看下Console里面Errors详细解释，应该会指出某个管脚分配的问题

小编是不是将差分时钟输入到DCM，同时又将此差分时钟驱动其余器件，如DDR等?

小编你好，我最近也出现过这种问题，就是在使用aurora核的时候。报错如下：希望帮忙解决一下
Pack:1107 - Pack was unable to combine the symbols listed below into a
   single IOB component because the site type selected is not compatible.
   Further explanation:
   The component type is determined by the types of logic and the properties and
   configuration of the logic it contains. In this case an IO component of type
   IOB was chosen because the IO contains symbols and/or properties consistent
   with input, output, or bi-directional usage and contains no other symbols or
   properties that require a more specific IO component type. Please double
   check that the types of logic elements and all of their relevant properties
   and configuration options are compatible with the physical site type of the
   constraint.
   Summary:
   Symbols involved:
   
PAD symbol "GTPD0_P" (Pad Signal = GTPD0_P)
   
DIFFAMP symbol "IBUFDS/IBUFDS" (Output Signal = GTPD0_left_i)
   Component type involved: IOB
   Site Location involved: A10
   Site Type involved: IPAD

Mapping completed.
See MAP report file "aurora_8b10b_v5_3_example_design_map.mrp" for details.
Problem encountered during the packing phase.

同问。

   我也是这个问题，时钟进来给DCM了，这个怎么回事呢，谢谢了。

good material