IDT72T7285/72T7295/72T72105/72T72115 2.5V TeraSync
16,384 x 72, 32,768 x 72, 65,536 x 72, 131,072 x 72
72-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
avoidedbycreatingcomposite flags, thatis, ANDingEF ofeveryFIFO, and
separately ANDing FF of every FIFO. In FWFT mode, composite flags can
be created by ORing OR of every FIFO, and separately ORing IR of every
FIFO.
Figure 36 demonstrates a width expansion using two IDT72T7285/
72T7295/72T72105/72T72115 devices. D0 - D71 from each device form a
144-bitwideinputbusandQ0-Q71fromeachdeviceforma144-bitwideoutput
bus. Any word width can be attained by adding additional IDT72T7285/
72T7295/72T72105/72T72115devices.
OPTIONALCONFIGURATIONS
WIDTH EXPANSION CONFIGURATION
Wordwidthmaybe increasedsimplybyconnectingtogetherthe control
signalsofmultipledevices. Statusflagscanbedetectedfromanyonedevice.
TheexceptionsaretheEFandFFfunctionsinIDTStandardmodeandtheIR
andORfunctionsinFWFTmode. BecauseofvariationsinskewbetweenRCLK
andWCLK, itis possible forEF/FF deassertionandIR/OR assertiontovary
byonecyclebetweenFIFOs. InIDTStandardmode,suchproblems canbe
SERIAL CLOCK (SCLK)
PARTIAL RESET (PRS)
MASTER RESET (MRS)
FIRST WORD FALL THROUGH/
SERIAL INPUT (FWFT/SI)
RETRANSMIT (RT)
Dm+1 - Dn
m + n
m
n
D0 - Dm
DATA IN
READ CLOCK (RCLK)
READ CHIP SELECT (RCS)
WRITE CLOCK (WCLK)
WRITE ENABLE (WEN)
LOAD (LD)
READ ENABLE (REN)
IDT
IDT
72T7285
72T7295
OUTPUT ENABLE (OE)
72T7285
72T7295
72T72105
72T72115
PROGRAMMABLE (PAE)
72T72105
#1
FULL FLAG/INPUT READY (FF/IR)
72T72115
(1)
GATE
EMPTY FLAG/OUTPUT READY (EF/OR) #1
(1)
FULL FLAG/INPUT READY (FF/IR) #2
GATE
EMPTY FLAG/OUTPUT READY (EF/OR) #2
FIFO
#2
m + n
PROGRAMMABLE (PAF)
HALF-FULL FLAG (HF)
n
FIFO
#1
Qm+1 - Qn
DATA OUT
m
5994 drw41
Q0 - Qm
NOTES:
1. Use an AND gate in IDT Standard mode, an OR gate in FWFT mode.
2. Do not connect any output control signals directly together.
3. FIFO #1 and FIFO #2 must be the same depth, but may be different word widths.
Figure 36. Block Diagram of 16,384 x 144, 32,768 x 144, 65,536 x 144 and 131,072 x 144 Width Expansion
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IDT [ INTEGRATED DEVICE TECHNOLOGY ]
