18 Mbit QDR II+ SRAM at 450 MHz — what this part is
It runs at a 450 MHz clock frequency, which means the memory delivers back-to-back read and write operations on every rising and falling edge — effectively doubling the data rate without dead cycles.
165-ball FBGA — what the package means for the board
The device comes in a 165-ball fine-pitch BGA (13x15 mm body). That is a surface-mount package requiring a multi-layer PCB with via-in-pad or microvia escape routing for the inner balls. Moisture sensitivity level (MSL) is not in the record, but a standard BGA bake-out before reflow is prudent if the bag seal is broken.