We are using a latest technique for data capturing which is called xilinx vertex -4tm device which has 64 tap absolute delay element built in each output/Input which is offering memory which is access very fast and very easy. This technique also provide many other services such as flexibility to choose and follow many data capture scheme such as clock data capturing technique or strobe data capture technique. If you are writing in external memory, Clock or strobe technique must be transferred specific aligned with according to specific data. Vertex 4 techniques also support to memory writes.