128K x 18 / 256K x 9 TeraSync FIFO, 2.5V

The IDT72T18105 are exceptionally deep, extremely high speed, CMOS First-In-First-Out (FIFO) memories with clocked read and write controls and a flexible Bus-Matching x18/x9 data flow. These FIFOs offer several key user benefits: Flexible x18/x9 Bus-Matching on both read and write ports A user selectable MARK location for retransmit User selectable I/O structure for HSTL or LVTTL Asynchronous/Synchronous translation on the read or write ports The first word data latency period, from the time the first word is written to an empty FIFO to the time it can be read, is fixed and short. High density offerings up to 9 Mbit. Bus-Matching TeraSync FIFOs are particularly appropriate for network, video, telecommunications, data communications and other applications that need to buffer large amounts of data and match busses of unequal sizes. Each FIFO has a data input port (Dn) and a data output port (Qn), both of which can assume either a 18-bit or a 9-bit width as determined by the state of external control pins Input Width (IW) and Output Width (OW) pin during the Master Reset cycle. The input port can be selected as either a Synchronous (clocked) interface, or Asynchronous interface. During Synchronous operation the input port is controlled by a Write Clock (WCLK) input and a Write Enable (WEN) input. Data present on the Dn data inputs is written into the FIFO on every rising edge of WCLK when WEN is asserted. During Asynchronous operation only the WR input is used to write data into the FIFO. Data is written on a rising edge of WR, the WEN input should be tied to its active state, (LOW).

• IDT72T18105 - 131,072 x 18/262,144 x 9 memory Organizations
• Up to 225 MHz Operation of Clocks
• User selectable HSTL/LVTTL Input and/or Output
• Read Enable & Read Clock Echo outputs aid high speed operation
• User selectable Asynchronous read and/or write port timing
• 2.5V LVTTL or 1.8V, 1.5V HSTL Port Selectable Input/Output voltage
• 3.3V Input tolerant
• Mark & Retransmit, resets read pointer to user marked position
• Write Chip Select (WCS) input enables/disables Write operations
• Read Chip Select (RCS) synchronous to RCLK
• Programmable Almost-Empty and Almost-Full flags, each flag can default to one of eight preselected offsets
• Program programmable flags by either serial or parallel means
• Selectable synchronous/asynchronous timing modes for Almost Empty and Almost-Full flags
• Big-Endian/Little-Endian user selectable byte representation
• Auto power down minimizes standby power consumption
• Master Reset clears entire FIFO
• Partial Reset clears data, but retains programmable settings
• Empty, Full and Half-Full flags signal FIFO status
• Select IDT Standard timing (using EF and FF flags) or First Word Fall Through timing (using OR and IR flags)
• Output enable puts data outputs into high impedance state