The IDT72V205/72V215/72V225/72V235/72V245 are functionally compatible versions of the IDT72205LB/72215LB/72225LB/72235LB/72245LB, designed to run off a 3.3V supply for exceptionally low power consumption. These devices are very high-speed, low-power First-In, First-Out (FIFO) memories with clocked read and write controls. These FIFOs are applicable for a wide variety of data buffering needs, such as optical disk controllers, Local Area Networks (LANs), and interprocessor communication. These FIFOs have 18-bit input and output ports. The input port is controlled by a free-running clock (WCLK), and an input enable pin (WEN). Data is read into the synchronous FIFO on every clock when WEN is asserted. The output port is controlled by another clock pin (RCLK) and another enable pin (REN). The Read Clock(RCLK) 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. An Output Enable pin (OE) is provided on the read port for three-state control of the output.