
Rev: 1.02  11/2000
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
1/26
 2000, Giga Semiconductor, Inc.
Preliminary
GS815018/32/36T-225/200/180/166/150/133
1M x 18, 512K x 32, 512K x 36
16Mb Sync Burst SRAMs
225 MHz–133 MHz
3.3 V V
DD
2.5 V or 3.3 V I/O
100-Pin TQFP
Commercial Temp
Industrial Temp
Features
 FT pin for user-configurable flow through or pipelined 
operation
 Single Cycle Deselect (SCD) operation
 3.3 V +10%/–5% 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 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 100-lead TQFP package
-225 -200 -180 -166 -150 -133 Unit
Pipeline
3-1-1-1
tCycle
Curr (x18)
Curr (x32)
Curr (x36)
410
370
Flow 
Through
2-1-1-1
Curr (x18)
Curr (x32)
Curr (x36)
240
210
Functional Description
Applications
The GS815018/32/36T is a 18,874,368-bit (16,777,216-bit for 
x32 version) 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 enables (E1, E2, E3), 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.
SCD Pipelined Reads
The GS815018/32/36T is a SCD (Single Cycle Deselect) 
pipelined synchronous SRAM. DCD (Dual Cycle Deselect) 
versions are also available. 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. 
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 GS815018/32/36T operates on a 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.
t
KQ
2.5
4.4
350
410
3.0
5.0
315
370
3.2
5.5
290
340
340
8
10
185
210
210
3.5
6.0
270
315
315
8.5
10
185
210
210
3.8
6.6
250
290
290
10
10
185
210
210
4.0
7.5
230
260
260
11
15
140
160
160
ns
ns
mA
mA
mA
ns
ns
mA
mA
mA
t
KQ
tCycle
7.0
8.5
205
240
7.5
10
185
210