Rev: 2.13 9/2002 1/28 © 1999, Giga Semiconductor, Inc.
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GS816018/32/36T-250/225/200/166/150/133
1M x 18, 512K x 32, 512K x 36
18Mb Sync Burst SRAMs
250 MHz–133 MHz
2.5 V or 3.3 V VDD
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 pipeline
operation
• Single Cycle Deselect (SCD) operation
• 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 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
Functional Description
Applications
The GS816018/32/36T is an 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.
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 GS816018/32/36T 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 (VDDQ) pins are used to decouple output noise
from the internal circuits and are 3.3 V and 2.5 V compatible.
-250 -225 -200 -166 -150 -133 Unit
Pipeline
3-1-1-1
tKQ
tCycle
2.5
4.0
2.7
4.4
3.0
5.0
3.4
6.0
3.8
6.7
4.0
7.5
ns
ns
3.3 V Curr (x18)
Curr (x32/x36)
280
330
255
300
230
270
200
230
185
215
165
190
mA
mA
2.5 V Curr (x18)
Curr (x32/x36)
275
320
250
295
230
265
195
225
180
210
165
185
mA
mA
Flow
Through
2-1-1-1
tKQ
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
3.3 V Curr (x18)
Curr (x32/x36)
175
200
165
190
160
180
150
170
145
165
135
150
mA
mA
2.5 V Curr (x18)
Curr (x32/x36)
175
200
165
190
160
180
150
170
145
165
135
150
mA
mA