General Description :
The fastest speed grades for the CoolRunner-II family have been removed. Designs in 6.x that target the fastest speed grade device issue an Information dialog box when the design is loaded into 7.1i for the first time.
When converting from a 6.x project to a 7.1i project, the ISE software automatically retargets to the next fastest speed grade in the same density/package. Make sure to verify timing in timing simulation.
The requests for the CoolRunner-II faster speed bin parts has not been as high as Xilinx had anticipated when individual device specifications were originally set for the family. We have released one family member (the XC2C32), and have not seen much volume in the way of production demand.
Based on this lower demand, the decision has been made to not release the fast speed bins on the other family members. They have been removed from the data sheets and the software, and we recommend that customers look at using the next speed bin device wherever possible.