What this DDR II SRAM brings to a high-throughput data path
The Infineon CY7C1321KV18-250BZXC is a 18 Mbit synchronous DDR II SRAM organized as 512K x 36, clocked at 250 MHz. It is a volatile memory in a 165-LBGA package (13x15 mm) for surface-mount assembly. The DDR II interface delivers data on both clock edges, effectively doubling the burst rate compared to a single-data-rate SRAM at the same clock frequency. This part is typically specified in networking line cards, telecom switching fabrics, and FPGA-based accelerators where the data bus is 36 bits wide and the system cannot tolerate the access-latency penalty of DRAM.
At 250 MHz, the DDR II interface transfers data at an effective 500 million transactions per second on each 36-bit word line. That translates to a peak bandwidth of roughly 18 Gbit/s (2.25 GB/s) per chip — enough to keep a modern FPGA or network processor fed without wait states. The 512K depth by 36-bit width is a natural fit for 36-bit wide memory buses common in high-end FPGAs and ASICs; you can pair multiple devices to build wider or deeper arrays without wasting pins.
Temperature range and package — where it fits and what the board needs
It is the current-speed variant (250 MHz) in the CY7C1321KV18 family.