512K x 36, 1M x 18
2.5V Synchronous ZBT™ SRAMs
2.5V I/O, Burst Counter
Flow-Through Outputs
IDT71T75702
IDT71T75902
Features
◆
The IDT71T75702/902 contain address, data-in and control signal
registers.Theoutputsareflow-through(nooutputdataregister).Output
enable is the only asynchronous signal and can be used to disable the
outputsatanygiventime.
AClockEnable(CEN)pinallowsoperationoftheIDT71T75702/902
to be suspended as long as necessary. All synchronous inputs are
ignoredwhenCENishighandtheinternaldeviceregisterswillholdtheir
previous values.
There are three chip enable pins (CE1, CE2, CE2) that allow the
usertodeselectthedevicewhendesired.Ifanyoneofthesethreeisnot
assertedwhenADV/LDislow,nonewmemoryoperationcanbeinitiated.
However,anypendingdatatransfers(readsorwrites)willbecompleted.
Thedatabuswilltri-stateonecycleafterthechipisdeselectedorawrite
isinitiated.
The IDT71T75702/902 have an on-chip burst counter. In the burst
mode,theIDT71T75702/902canprovidefourcyclesofdataforasingle
address presented to the SRAM. The order of the burst sequence is
defined by the LBO input pin. The LBO pin selects between linear and
interleaved burst sequence. The ADV/LD signal is used to load a new
externaladdress(ADV/LD=LOW)orincrementtheinternalburstcounter
(ADV/LD = HIGH).
512K x 36, 1M x 18 memory configurations
◆
Supports high performance system speed - 100 MHz
(7.5 ns Clock-to-Data Access)
ZBT Feature - No dead cycles between write and read cycles
Internally synchronized output buffer enable eliminates the
need to control OE
Single R/W (READ/WRITE) control pin
4-word burst capability (Interleaved or linear)
Individual byte write (BW1 - BW4) control (May tie active)
Three chip enables for simple depth expansion
2.5V power supply (±5%)
2.5V (±5%) I/O Supply (VDDQ)
Power down controlled by ZZ input
◆
◆
TM
◆
◆
◆
◆
◆
◆
◆
◆
◆
Boundary Scan JTAG Interface (IEEE 1149.1 Compliant)
Packaged in a JEDEC standard 100-pin plastic thin quad
flatpack (TQFP), 119 ball grid array (BGA)
Description
The IDT71T75702/902 are 2.5V high-speed 18,874,368-bit
(18 Megabit) synchronous SRAMs organized as 512K x 36 /1M x 18.
They are designed to eliminate dead bus cycles when turning the bus
aroundbetweenreadsandwrites,orwritesandreads.Thustheyhave
The IDT71T75702/902 SRAMs utilize IDT’s high-performance
CMOSprocess,andarepackagedinaJEDECStandard14mmx20mm
100-pinplasticthinquadflatpack(TQFP)aswellasa119 ballgridarray
(BGA).
TM
been given the name ZBT , or Zero Bus Turnaround.
AddressandcontrolsignalsareappliedtotheSRAMduringoneclock
cycle,andonthenextclockcycletheassociateddatacycleoccurs,be
it read or write.
PinDescriptionSummary
A0-A19
Ad d re ss Inp uts
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Output
Input
Input
I/ O
Synchronous
Synchronous
Asynchronous
Synchronous
Synchronous
Synchronous
N/A
Chip Enables
CE1, CE2, CE2
OE
Output Enable
W
R/
CEN
BW1 BW2 BW3 BW4
Read/Write Signal
Clock Enable
Individual Byte Write Selects
Clock
,
,
,
CLK
ADV/LD
Advance Burst Address/Load New Address
Linear/Interleaved Burst Order
Tes t Mo de S el e ct
Test Data Input
Synchronous
Static
LBO
TMS
TDI
N/A
N/A
TCK
TDO
Te s t C loc k
N/A
Te s t D ata Outp ut
JTAG Reset (Optional)
Sleep Mode
N/A
Asynchronous
Synchronous
Synchronous
Static
TRST
ZZ
I/ O0-I/O31, I/OP1-I/OP4
VDD, VDDQ
Data Input/Output
Co re Po wer, I/O Power
Ground
Supply
Supply
VSS
Static
5319 tbl 01
APRIL 2004
1
©2004IntegratedDeviceTechnology,Inc.
DSC-5319/08