128K x 36, 3.3V Synchronous IDT71V546S/XS
SRAM with ZBT™ Feature,
Burst Counter and Pipelined Outputs
Features
◆
128K x 36 memory configuration, pipelined outputs
Supports high performance system speed - 133 MHz
(4.2 ns Clock-to-Data Access)
clock cycle, and two cycles later its associated data cycle occurs, be it
read or write.
TheIDT71V546containsdataI/O,addressandcontrolsignalregis-
ters. Outputenableistheonlyasynchronoussignalandcanbeusedto
disabletheoutputsatanygiventime.
A Clock Enable (CEN) pin allows operation of the IDT71V546 to be
suspended as long as necessary. All synchronous inputs are ignored
whenCENishighandtheinternaldeviceregisterswillholdtheirprevious
values.
Therearethreechipenablepins(CE1,CE2,CE2)thatallowtheuser
todeselectthedevicewhendesired. Ifanyoneofthesethreeisnotactive
whenADV/LDislow,nonewmemoryoperationcanbeinitiatedandany
burst that was in progress is stopped. However, any pending data
transfers(readsorwrites)willbecompleted. Thedatabuswilltri-statetwo
cyclesafterthechipisdeselectedorawriteinitiated.
◆
◆
◆
ZBTTM Feature - No dead cycles between write and read
cycles
Internally synchronized registered outputs eliminate the
need to control OE
◆
◆
Single R/W (READ/WRITE) control pin
Positive clock-edge triggered address, data, and control
signal registers for fully pipelined applications
4-word burst capability (interleaved or linear)
Individual byte write (BW1 - BW4) control (May tie active)
Three chip enables for simple depth expansion
Single 3.3V power supply (±5%)
◆
◆
◆
◆
◆
Packaged in a JEDEC standard 100-pin TQFP package
TheIDT71V546hasanon-chipburstcounter. Intheburstmode,the
IDT71V546canprovidefourcyclesofdataforasingleaddresspresented
totheSRAM. TheorderoftheburstsequenceisdefinedbytheLBOinput
pin. TheLBOpinselectsbetweenlinearandinterleavedburstsequence.
The ADV/LD signal is used to load a new external address (ADV/LD =
LOW) or increment the internal burst counter (ADV/LD = HIGH).
TheIDT71V546SRAMutilizesIDT'shigh-performance,high-volume
3.3V CMOS process, and is packaged in a JEDEC standard 14mm x
20mm100-pinthinplasticquadflatpack(TQFP)forhighboarddensity.
Description
The IDT71V546 is a 3.3V high-speed 4,718,592-bit (4.5 Megabit)
synchronous SRAM organized as 128K x 36 bits. It is designed to
eliminatedeadbuscycleswhenturningthebusaroundbetweenreads
andwrites,orwritesandreads. ThusithasbeengiventhenameZBTTM,
or Zero Bus Turn-around.
Address and control signals are applied to the SRAM during one
PinDescriptionSummary
A
0
- A16
Address Inputs
Input
Input
Input
Input
Input
Input
Input
Input
Input
I/O
Synchronous
Synchronous
Asynchronous
Synchronous
Synchronous
Synchronous
N/A
Three Chip Enables
Output Enable
CE1
, CE
2
, CE
2
OE
R/W
Read/Write Signal
Clock Enable
CEN
Individual Byte Write Selects
Clock
BW
1
, BW
2
, BW
3
, BW
4
CLK
ADV/LD
Advance Burst Address / Load New Address
Linear / Interleaved Burst Order
Data Input/Output
Synchronous
Static
LBO
I/O0
- I/O31, I/OP1 - I/OP4
Synchronous
Static
V
DD
SS
3.3V Power
Supply
Supply
V
Ground
Static
3821 tbl 01
OCTOBER 2008
ZBT and Zero Bus Turnaround are trademarks of Integrated Device Technology, Inc. and the architecture is supported by Micron Technology and Motorola Inc.
1
DSC-3821/05
©2008 Integrated Device Technology, Inc.