24bit comparator in ise12.1

[maia31]

in ise12.1
in schematic i want create 24bit comparator

i use 3
8-Bit Identity Comparator
but when i connect one of input port of them to each other
it remain
a(7:0) and doesn't change to a(23:0)
what should i do?

 

[treqer]

did not understand. If you use 3 identical comparator. It is necessary to compare their every 8 data bits and the result is to connect the matrix of decision-making. And better to do comparator on the basis of the subtractor with the required word length