66.7 MHz synchronous FIFO — the speed tier for the bus
The Cypress CY7C4205V-15ASXCT is a synchronous FIFO memory from the CY7C series, organized as 256 words by 18 bits for a total of 4.5 Kbit. The part supports depth and width expansion, includes programmable flags and retransmit capability, and is uni-directional. Typical applications include buffering in telecom, networking, and DSP datapaths where a synchronous handshake and moderate depth are needed.
11 ns access time — read-cycle margin
At a 66.7 MHz clock (15 ns period), this leaves 4 ns of setup margin for the host controller — enough for most 3.3 V logic families, but tight if the board has long traces or multiple loads. The 30 mA maximum supply current gives a rough power budget: at 3.3 V, about 100 mW worst-case, so no special thermal management is needed in the 64-TQFP package.