Cypress’s QDR-II+ Xtreme is a high performance, dual-port SRAM memory. QDR-II+ Xtreme SRAM operates up to 633 MHz and is available in 36 Mb or 72 Mb densities. Cypress's Xtreme line of QDR-II+ and DDR-II+ devices are fit-, form-, and function- compatible with existing QDR-II+ family devices, allowing manufacturers of network switches, routers, and aggregation platforms to boost performance by increasing clock speeds without board layout changes.
DDR-II+ Xtreme devices are similar to QDR-II+ Xtreme devices except that all DDR devices have a burst length of 2 and a single data rate address bus. DDR-II+ Xtreme devices provide a single port for reads and writes, reducing the number of required data pin connections.