
GS88237BB/D-333/300/250/200
256K x 36
9Mb SCD/DCD Sync Burst SRAM
333 MHz–200 MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
119- & 165-Bump BGA
Commercial Temp
Industrial Temp
Rev:  1.04  3/2005
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
1/29
 2002, GSI Technology
Features
 Single/Dual Cycle Deselect selectable
 IEEE 1149.1 JTAG-compatible Boundary Scan
 ZQ mode pin for user-selectable high/low output drive
 2.5 V or 3.3 V +10%/–10% core power supply
 2.5 V or 3.3 V I/O supply
 LBO pin for Linear or Interleaved Burst mode
 Internal input resistors on mode pins allow floating mode pins
 Default to SCD x18/x36 Interleaved Pipeline mode
 Byte Write (BW) and/or Global Write (GW) operation
 Internal self-timed write cycle
 Automatic power-down for portable applications
 JEDEC-standard 119-bump and 165-bump BGA packages
 Pb-Free 119-bump and 165-bump BGA packages available
Functional Description
Applications
The GS88237BB/D is a 9,437,184-bit high performance 
synchronous SRAM with a 2-bit burst address counter. 
Although of a type originally developed for Level 2 Cache 
applications supporting high performance CPUs, the device 
now finds application in synchronous SRAM applications, 
ranging from DSP main store to networking chip set support. 
Controls 
Addresses, data I/Os, chip enable (E1), address burst control 
inputs (ADSP, ADSC, ADV), and write control inputs (Bx, 
BW, GW) are synchronous and are controlled by a positive-
edge-triggered clock input (CK). Output enable (G) and power 
down control (ZZ) are asynchronous inputs. Burst cycles can 
be initiated with either ADSP or ADSC inputs. In Burst mode, 
subsequent burst addresses are generated internally and are 
controlled by ADV. The burst address counter may be 
configured to count in either linear or interleave order with the 
Linear Burst Order (LBO) input. The Burst function need not 
be used. New addresses can be loaded on every cycle with no 
degradation of chip performance.
SCD and DCD Pipelined Reads
The GS88237BB/D is a SCD (Single Cycle Deselect) and 
DCD (Dual Cycle Deselect)  pipelined synchronous SRAM.  
DCD SRAMs pipeline disable commands to the same degree 
as read commands. SCD SRAMs pipeline deselect commands 
one stage less than read commands. SCD RAMs begin turning 
off their outputs immediately after the deselect command has 
been captured in the input registers. DCD RAMs hold the 
deselect command for one full cycle and then begin turning off 
their outputs just after the second rising edge of clock. The user 
may configure this SRAM for either mode of operation using 
the SCD mode input. 
Byte Write and Global Write
Byte write operation is performed by using Byte Write enable 
(BW) input combined with one or more individual byte write 
signals (Bx). In addition, Global Write (GW) is available for 
writing all bytes at one time, regardless of the Byte Write 
control inputs. 
FLXDrive
The ZQ pin allows selection between high drive strength (ZQ 
low) for multi-drop bus applications and normal drive strength 
(ZQ floating or high) point-to-point applications. See the 
Output Driver Characteristics chart for details.
Sleep Mode
Low power (Sleep mode) is attained through the assertion 
(High) of the ZZ signal, or by stopping the clock (CK). 
Memory data is retained during Sleep mode. 
Core and Interface Voltages
The GS88237BB/D operates on a 2.5 V or 3.3 V power supply. 
All input are 3.3 V and 2.5 V compatible. Separate output 
power (V
DDQ
) pins are used to decouple output noise from the 
internal circuits and are 3.3 V and 2.5 V compatible.
Parameter Synopsis
-333
2.0
3.0
435
435
-300
2.2
3.3
395
395
-250
2.3
4.0
330
330
-200
2.7
5.0
270
270
Unit
ns
ns
mA
mA
Pipeline
3-1-1-1
3.3 V
2.5 V
t
KQ
tCycle
Curr 
(x36)
Curr 
(x36)