A FIFO memory is a storage device that allows data to be written into and read from its array at independent data rates. The SN74ABT7819A is a high-speed, low-power, BiCMOS, bidirectional, clocked FIFO memory. Two independent 512 × 18 dual-port SRAM FIFOs (FIFOA, FIFOB) on the chip buffer data in opposite directions. Each FIFO has flags to indicate empty and full conditions, a half-full flag, and a programmable almost-full/almost-empty flag.

The SN74ABT7819A is a clocked FIFO, which means each port employs a synchronous interface. All data transfers through a port are gated to the low-to-high transition of a continuous (free-running) port clock by enable signals. The continuous clocks for each port are independent of one another and can be asynchronous or coincident.