The CY7C1663KV18， and CY7C1665KV18 are 1.8-V synchronous pipelined SRAMs， equipped with QDR II+ architecture. Similar to QDR II architecture， QDR II+ architecture consists of two separate ports： the read port and the write port to access the memory array. The read port has dedicated data outputs to support read operations and the write port has dedicated data inputs to support write operations. QDR II+ architecture has separate data inputs and data outputs to completely eliminate the need to “turnaround” the data bus that exists with common I/O devices. Each port is accessed through a common address bus. Addresses for read and write addresses are latched on alternate rising edges of the input （K） clock. Accesses to the QDR II+ read and write ports are completely independent of one another. To maximize data throughput， both read and write ports are equipped with DDR interfaces. Each address location is associated with four 18-bit words （CY7C1663KV18）， or 36-bit words （CY7C1665KV18） that burst sequentially into or out of the device. Because data is transferred into and out of the device on every rising edge of both input clocks （K and K）， memory bandwidth is maximized while simplifying system design by eliminating bus “turnarounds”。 Depth expansion is accomplished with port selects， which enables each port to operate independently. All synchronous inputs pass through input registers controlled by the K or K input clocks. All data outputs pass through output registers controlled by the K or K input clocks. Writes are conducted with on-chip synchronous self-timed write circuitry. For a complete list of related documentation， click here.