The 72V845 is a 4K x 18 dual sync FIFO with clocked read and write controls that is functionally equivalent to two 72V245 FIFO's in a single package with all associated control, data, and flag lines assigned to independent pins. This FIFO is useful for optical disk controllers, Local Area Networks (LANs), and interprocessor communication. Each of the two FIFOs has an 18-bit input and output port. The Read Clock can be tied to the Write Clock for single clock operation or the two clocks can run asynchronous of one another for dual-clock operation.