128K x 36, 256K x 18
IDT71V2577
IDT71V2579
3.3V Synchronous SRAMs
2.5V I/O, Flow-Through Outputs
Burst Counter, Single Cycle Deselect
Description
Features
◆
The IDT71V2577/79 are high-speed SRAMs organized as
128Kx36/256Kx18.TheIDT71V2577/79SRAMs containwrite,data,
address andcontrolregisters.Therearenoregisters inthedataoutput
path (flow-through architecture). Internal logic allows the SRAM to
generateaself-timedwritebaseduponadecisionwhichcanbeleftuntil
128K x 36, 256K x 18 memory configurations
◆
Supports fast access times:
Commercial:
– 7.5ns up to 117MHz clock frequency
CommercialandIndustrial:
– 8.0ns up to 100MHz clock frequency
– 8.5ns up to 87MHz clock frequency
LBO input selects interleaved or linear burst mode
Self-timedwritecyclewithglobalwritecontrol(GW),bytewrite
enable (BWE), and byte writes (BWx)
3.3V core power supply
Power down controlled by ZZ input
2.5V I/O
theendofthewritecycle.
Theburstmodefeatureoffersthehighestlevelofperformancetothe
systemdesigner,astheIDT71V2577/79canprovidefourcyclesofdata
fora single address presentedtothe SRAM. Aninternalburstaddress
counteracceptsthefirstcycleaddressfromtheprocessor,initiatingthe
accesssequence.Thefirstcycleofoutputdatawillflow-throughfromthe
arrayafteraclock-to-dataaccesstimedelayfromtherisingclockedgeof
the same cycle. If burst mode operation is selected (ADV=LOW), the
subsequentthreecyclesofoutputdatawillbeavailabletotheuseronthe
next three rising clock edges. The order of these three addresses are
definedbytheinternalburstcounterandtheLBOinputpin.
◆
◆
◆
◆
◆
◆
Packaged in a JEDEC Standard 100-pin plastic thin quad
flatpack(TQFP),119ballgridarray(BGA)and165finepitchball
grid array (fBGA)
The IDT71V2577/79 SRAMs utilize IDT’s latest high-performance
CMOSprocessandarepackagedinaJEDECstandard14mmx20mm
100-pinthinplasticquadflatpack(TQFP)aswellasa119ballgridarray
(BGA) and a 165 fine pitch ball grid array (fBGA).
PinDescriptionSummary
0
17
A -A
Address Inputs
Input
Input
Input
Input
Input
Input
Input
Synchronous
Synchronous
Synchronous
Asynchronous
Synchronous
Synchronous
Synchronous
Chip Enable
CE
0
1
CS , CS
Chip Selects
Output Enable
OE
Global Write Enable
Byte Write Enable
Individual Byte Write Selects
GW
BWE
(1)
1
2
3
4
BW , BW , BW , BW
CLK
ADV
ADSC
ADSP
LBO
Clock
Input
Input
Input
Input
Input
Input
I/O
N/A
Synchronous
Synchronous
Synchronous
DC
Burst Address Advance
Address Status (Cache Controller)
Address Status (Processor)
Linear / Interleaved Burst Order
Sleep Mode
ZZ
Asynchronous
Synchronous
N/A
0
31
P1
P4
I/O -I/O , I/O -I/O
Data Input / Output
DD DDQ
V , V
Core Power, I/O Power
Ground
Supply
Supply
SS
V
N/A
4877 tbl 01
NOTE:
1. BW3 and BW4 are not applicable for the IDT71V2579.
OCTOBER 2000
1
©2000ntegratedDeviceTechnology,Inc.
DSC-4877/06