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Product Attributes

Introduction

The IDT72V36100/72V36110 are exceptionally deep, high speed, CMOS First-In-First-Out (FIFO) memories with clocked read and write controls and a flexible Bus-Matching ×36/×18/×9 data flow. These FIFOs offer several key user benefits:

• Flexible x36/x18/x9 Bus-Matching on both read and write ports
• The period required by the retransmit operation is fixed and short.
• 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.
• Asynchronous/Synchronous translation on the read or write ports
• High density offerings up to 4 Mbit

Bus-Matching Sync 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 36-bit, 18-bit or a 9-bit width as determined by the state of external control pins Input Width (IW), Output Width (OW), and BusMatching (BM) 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).

The output port can be selected as either a Synchronous (clocked) interface, or Asynchronous interface. During Synchronous operation the output port is controlled by a Read Clock (RCLK) input and Read Enable (REN) input. Data is read from the FIFO on every rising edge of RCLK when REN is asserted. During Asynchronous operation only the RD input is used to read data from the FIFO. Data is read on a rising edge of RD, the REN input should be tied to its active state, LOW. When Asynchronous operation is selected on the output port the FIFO must be configured for Standard IDT mode, and the OE input used to provide three-state control of the outputs, Qn.

The frequencies of both the RCLK and the WCLK signals may vary from 0 to fMAX with complete independence. There are no restrictions on the frequency of the one clock input with respect to the other.

There are two possible timing modes of operation with these devices: IDT Standard mode and First Word Fall Through (FWFT) mode.

In IDT Standard mode, the first word written to an empty FIFO will not appear on the data output lines unless a specific read operation is performed. A read operation, which consists of activating REN and enabling a rising RCLK edge, will shift the word from internal memory to the data output lines.

In FWFT mode, the first word written to an empty FIFO is clocked directly to the data output lines after three transitions of the RCLK signal. A REN does not have to be asserted for accessing the first word. However, subsequent words written to the FIFO do require a LOW on REN for access. The state of the FWFT/SI input during Master Reset determines the timing mode in use.

For applications requiring more data storage capacity than a single FIFO can provide, the FWFT timing mode permits depth expansion by chaining FIFOs in series (i.e. the data outputs of one FIFO are connected to the corresponding data inputs of the next). No external logic is required.

Features

• Choose among the following memory organizations: 65,536 x 36; 131,072 x 36
• Higher density, 2Meg and 4Meg SuperSync II FIFOs
• Up to 166 MHz Operation of the Clocks
• User selectable Asynchronous read and/or write ports (PBGA Only)
• User selectable input and output port bus-sizing: x36 in to x36 out; x36 in to x18 out; x36 in to x9 out; x18 in to x36 out; x9 in to x36 out
• Big-Endian/Little-Endian user selectable byte representation
• 5V input tolerant
• Fixed, low first word latency
• Zero latency retransmit
• 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
• Programmable Almost-Empty and Almost-Full flags, each flag can default to one of eight preselected offsets
• Selectable synchronous/asynchronous timing modes for AlmostEmpty and Almost-Full flags
• Program programmable flags by either serial or parallel means
• Select IDT Standard timing (using EF and FF flags) or First Word Fall Through timing (using 0.8 (overline) and |R (overline) flags)
• Output enable puts data outputs into high impedance state
• Easily expandable in depth and width
• JTAG port, provided for Boundary Scan function (PBGA Only)
• Independent Read and Write Clocks (permit reading and writing simultaneously)
• Available in a 128-pin Thin Quad Flat Pack (TQFP) or a 144-pin Plastic Ball Grid Array (PBGA) (with additional features)
• Pin compatible to the SuperSync II (IDT72V3640/72V3650/72V3660/ 72V3670/72V3680/72V3690) family
• High-performance submicron CMOS technology
• Industrial temperature range (-40℃ to +85℃) is available
• Green parts available

Applications

• network
• video
• telecommunications
• data communications