Chipscope with clock enable.

Hi, I'm trying to use Chipscope with a Virtex-e design. Problem is that my design runs with a very fast clock (>170 MHz) which is clock enabled. Chipscope needs a measurement clock and I wondered if it supports a clock enable? It can't run at the full clock rate. I couldn't find that option, so I guess I'll need to make a special clock for it. TIA, Syms.