
GS8161Z18(T/D)/GS8161Z32(D)/GS8161Z36(T/D)
18Mb Pipelined and Flow Through 
Synchronous NBT SRAM
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:  2.15  11/2004
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
1/36
 1998, GSI Technology
Features
 User-configurable Pipeline and Flow Through mode
 NBT (No Bus Turn Around) functionality allows zero wait 
read-write-read bus utilization 
 Fully pin-compatible with both pipelined and flow through 
NtRAM, NoBL and ZBT SRAMs
 IEEE 1149.1 JTAG-compatible Boundary Scan
 2.5 V or 3.3 V +10%/–10% core power supply
 LBO pin for Linear or Interleave Burst mode
 Pin-compatible with 2M, 4M, and 8M devices
 Byte write operation (9-bit Bytes)
 3 chip enable signals for easy depth expansion
 ZZ pin for automatic power-down
 JEDEC-standard 100-lead TQFP and 165-bump FP-BGA 
packages
Functional Description
The GS8161Z18(T/D)/GS8161Z32(D)/GS8161Z36(T/D) is an 
18Mbit Synchronous Static SRAM. GSI's NBT SRAMs, like 
ZBT, NtRAM, NoBL or other pipelined read/double late write 
or flow through read/single late write SRAMs, allow 
utilization of all available bus bandwidth by eliminating the 
need to insert deselect cycles when the device is switched from 
read to write cycles. 
Because it is a synchronous device, address, data inputs, and 
read/ write control inputs are captured on the rising edge of the 
input clock. Burst order control (LBO) must be tied to a power 
rail for proper operation. Asynchronous inputs include the 
Sleep mode enable, ZZ and Output Enable. Output Enable can 
be used to override the synchronous control of the output 
drivers and turn the RAM's output drivers off at any time. 
Write cycles are internally self-timed and initiated by the rising 
edge of the clock input. This feature eliminates complex off-
chip write pulse generation required by asynchronous SRAMs 
and simplifies input signal timing. 
The GS8161Z18(T/D)/GS8161Z32(D)/GS8161Z36(T/D)  may 
be configured by the user to operate in Pipeline or Flow 
Through mode. Operating as a pipelined synchronous device, 
in addition to the rising-edge-triggered registers that capture 
input signals, the device incorporates a rising-edge-triggered 
output register. For read cycles, pipelined SRAM output data is 
temporarily stored by the edge triggered output register during 
the access cycle and then released to the output drivers at the 
next rising edge of clock. 
The GS8161Z18(T/D)/GS8161Z32(D)/GS8161Z36(T/D) is 
implemented with GSI's high performance CMOS technology 
and is available in  JEDEC-standard 100-pin TQFP and 
165-bump FP-BGA packages. 
Parameter Synopsis
-250 -225 -200 -166 -150 -133 Unit
2.5
4.0
4.4
5.0
6.0
280
330
300
270
230
275
320
295
265
225
Pipeline
3-1-1-1
t
KQ
tCycle
Curr 
(x18)
Curr 
(x32/x36)
Curr 
(x18)
Curr 
(x32/x36)
2.7
3.0
3.4
3.8
6.7
185
215
180
210
4.0
7.5
165
190
165
185
ns
ns
mA
mA
mA
mA
3.3 V
255
230
200
2.5 V
250
230
195
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
8.5
8.5
ns
ns
3.3 V
Curr 
(x18)
Curr 
(x32/x36)
Curr 
(x18)
Curr 
(x32/x36)
175
200
175
200
165
190
165
190
160
180
160
180
150
170
150
170
145
165
145
165
135
150
135
150
mA
mA
mA
mA
2.5 V