The 72V3642 is a 3.3V version of the 723642. Two independent 1K x 36 dual-port SRAM FIFOs onboard each chip buffer data in opposite directions. Communication between each port may bypass the FIFOs via two 36-bit mailbox registers. 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.