DT72281_13 Datasheet, PDF (1/26 Pages) Integrated Device Technology – CMOS SuperSync FIFO

CMOS SuperSync FIFO™
65,536 x 9
131,072 x 9
IDT72281
IDT72291
FEATURES:
• Choose among the following memory organizations:
IDT72281 65,536 x 9
IDT72291 131,072 x 9
• Pin-compatible with the IDT72261LA/72271LA SuperSync FIFOs
• 10ns read/write cycle time (6.5ns access time)
• Fixed, low first word data latency time
• Auto power down minimizes standby power consumption
• Master Reset clears entire FIFO
• Partial Reset clears data, but retains programmable
settings
• Retransmit operation with fixed, low first word data
latency time
• Empty, Full and Half-Full flags signal FIFO status
• Programmable Almost-Empty and Almost-Full flags, each flag
can default to one of two preselected offsets
• Program partial flags by either serial or parallel means
• 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
• Easily expandable in depth and width
• Independent Read and Write clocks (permit reading and writing
simultaneously)
• Available in the 64-pin Thin Quad Flat Pack (TQFP) and the 64-
pin Slim Thin Quad Flat Pack (STQFP)
• High-performance submicron CMOS technology
• Industrial temperature range (-40°C to +85°C) is available
DESCRIPTION:
The IDT72281/72291 are exceptionally deep, high speed, CMOS First-In-
First-Out (FIFO) memories with clocked read and write controls. These FIFOs
offer numerous improvements over previous SuperSync FIFOs, including the
following:
• Thelimitationofthefrequencyofoneclockinputwithrespecttotheotherhas
been removed. The Frequency Select pin (FS) has been removed, thus
it is no longer necessary to select which of the two clock inputs, RCLK or
WCLK, is running at the higher frequency.
• The period required by the retransmit operation is now fixed and short.
• Thefirstworddatalatencyperiod,fromthetimethefirstwordiswrittentoan
empty FIFO to the time it can be read, is now fixed and short. (The variable
clock cycle counting delay associated with the latency period found on
previous SuperSync devices has been eliminated on this SuperSync family.)
SuperSync FIFOs are particularly appropriate for network, video, telecom-
munications, data communications and other applications that need to buffer
large amounts of data.
FUNCTIONAL BLOCK DIAGRAM
WEN _WCLK
D0 -D8
LD _SEN
WRITE CONTROL
LOGIC
WRITE POINTER
INPUT REGISTER
RAM ARRAY
65,536 x 9
131,072 x 9
OFFSET REGISTER
FLAG
LOGIC
READ POINTER
FF/IR
PAF
EF/OR
PAE
HF
FWFT/SI
MRS
PRS
RESET
LOGIC
OUTPUT REGISTER
READ
CONTROL
RT
LOGIC
RCLK
REN
Q0 -Q8
OE
IDT, IDT logo are registered trademarks of Integrated Device Technology, Inc. The SuperSync FIFO is a trademark of Integrated Device Technology, Inc.
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
1
© 2013 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.
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