QDRII Extra half Cycle latency

Question: Why does QDR-II have extra 1/2 clock cycle latency?

 

Answer:

Response: This is one of the primary differences between QDR and QDR II. An extra 1/2 cycle latency was introduced in QDR II in order to increase the data valid window at this high frequency. Also, please note that this data is clocked out by the internal DLL which runs off of the main clock(K and /K). Please refer to AN5062 for more information.