IDT72225LB

The IDT72225LB are very high-speed, low-power First-In, First-Out (FIFO) memories with clocked read and write controls. These FIFOsare applicable for a wide variety of data buffering needs, such as optical disk controllers, Local Area Networks (LANs), and interprocessor communication.

These FIFOs of the IDT72225LB 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 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.

The synchronous FIFOs of the IDT72225LB have two fixed flags, Empty (EF) and Full (FF), and two programmable flags, Almost-Empty (PAE) and Almost-Full (PAF). The offset loading of the programmable flags is controlled by a simple state machine, and is initiated by asserting the Load pin (LD). A Half-Full flag (HF) is available when the FIFO is used in a single device configuration.

These devices of the IDT72225LB are depth expandable using a Daisy-Chain technique. The XI and XO pins are used to expand the FIFOs. In depth expansion configuration, FL is grounded on the first device and set to HIGH for all other devices in the Daisy Chain.

The IDT72225LB is fabricated using IDT's high-speed submicron CMOS technology.