
GS881E18/36AT-250/225/200/166/150/133
512K x 18, 256K x 36 
9Mb Synchronous Burst SRAMs
250 MHz
–
133 MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
100-Pin TQFP
Commercial Temp
Industrial Temp
Rev:  1.03  11/2004
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
1/29
 2001, GSI Technology
Features
 Dual Dycle Deselect  (DCD) operation
 IEEE 1149.1 JTAG-compatible Boundary Scan
 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
 Byte Write (BW) and/or Global Write (GW) operation
 Internal self-timed write cycle
 Automatic power-down for portable applications
 JEDEC-standard  package
Functional Description
Applications
The GS881E18/36AT 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, E2), 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.
Flow Through/Pipeline Reads
The function of the Data Output register can be controlled by 
the user via the FT mode pin (Pin 14). Holding the FT mode 
pin low places the RAM in Flow Through mode, causing 
output data to bypass the Data Output Register. Holding FT 
high places the RAM in Pipeline mode, activating the rising-
edge-triggered Data Output Register.
DCD Pipelined Reads
The GS881E18/36AT is a DCD (Dual Cycle Deselect) 
pipelined synchronous SRAM. SCD (Single Cycle Deselect) 
versions are also available. DCD SRAMs pipeline disable 
commands to the same degree as read commands. 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. 
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. 
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 GS881E18/36AT 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
-250 -225 -200 -166 -150 -133 Unit
2.5
4.0
4.4
5.0
6.0
280
330
300
270
230
Pipeline
3-1-1-1
t
KQ
tCycle
Curr (x18)
Curr (x36)
2.7
3.0
3.4
3.8
6.7
185
215
4.0
7.5
165
190
ns
ns
mA
mA
255
230
200
Flow 
Through
2-1-1-1
t
KQ
tCycle
5.5
5.5
6.0
6.0
6.5
6.5
7.0
7.0
7.5
7.5
8.5
8.5
ns
ns
Curr (x18)
Curr (x36)
175
200
165
190
160
180
150
170
145
165
135
150
mA
mA