The SN54ACT3632 is a high-speed, low-power CMOS clocked bidirectional FIFO memory. It supports clock frequencies up to 50 MHz and has read access times as fast as 11 ns. Two independent 512 x 36 dual-port SRAM FIFOs on the chip buffer data in opposite directions. Each FIFO has flags to indicate empty and full conditions and two programmable flags (almost full and almost empty) to indicate when a selected number of words is stored in memory. Communication between each port can bypass the FIFOs via two 36-bit mailbox registers. Each mailbox register has a flag to signal when new mail has been stored. Two or more devices can be used in parallel to create wider data paths. The SN54ACT3632 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 port clock by enable signals. The clocks for each port are independent of one another and can be asynchronous or coincident. The enables for each port are arranged to provide a simple bidirectional interface between microprocessors and/or buses with synchronous control.