The Cypress CY7C1518V18-167BZC is a 72 Mbit synchronous DDR II SRAM organized as 4M x 18 bits. The 167 MHz clock rate supports high-bandwidth read and write operations with double-data-rate transfer on each clock edge.
At 167 MHz, the DDR II interface delivers a data rate of 333 million transfers per second on an 18-bit-wide bus. That bandwidth suits packet buffers and look-up tables in switches and routers where the memory must keep up with the line rate. The 1.7V to 1.9V core supply is tighter than a standard 1.8V rail — the regulator needs to hold within that window under load transients. The 165-ball FBGA (15x17 mm) footprint requires a multi-layer PCB with controlled impedance traces for the clock and data lines.