400 MHz QDR II+ — what the clock rate means for the bus
The CY7C1263KV18-400BZXI is a 36 Mbit QDR II+ synchronous SRAM from Infineon, organized 2M x 18. The 400 MHz clock rate means each port (read and write) transfers data on both edges, giving an effective 800 MT/s per port — the limiting factor in a high-throughput buffer or look-up table is the FPGA or ASIC interface, not the SRAM.
Package and supply — board-fit realities
The core supply is 1.7 V to 1.9 V, a single rail that needs ±5 % regulation; a 1.8 V rail with 50 mV ripple is the typical design target. The parallel memory interface means the bus traces must be length-matched to the controller — a layout constraint, not a parametric one.