GS88018/32/36AT-250/225/200/166/150/133
100-Pin TQFP
Commercial Temp
Industrial Temp
250 MHz–133 MHz
512K x 18, 256K x 32, 256K x 36
9Mb Sync Burst SRAMs
2.5 V or 3.3 V VDD
2.5 V or 3.3 V I/O
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.
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
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 (BW) and/or Global Write (GW) operation
• Internal self-timed write cycle
• Automatic power-down for portable applications
• JEDEC-standard 100-lead TQFP package
-250 -225 -200 -166 -150 -133 Unit
SCD Pipelined Reads
Pipeline
3-1-1-1
t
2.5 2.7 3.0 3.4 3.8 4.0 ns
4.0 4.4 5.0 6.0 6.7 7.5 ns
KQ
The GS88018/32/36AT 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.
tCycle
Curr (x18) 280 255 230 200 185 165 mA
Curr (x32/x36) 330 300 270 230 215 190 mA
3.3 V
2.5 V
Curr (x18) 275 250 230 195 180 165 mA
Curr (x32/x36) 320 295 265 225 210 185 mA
Flow
Through
2-1-1-1
t
5.5 6.0 6.5 7.0 7.5 8.5 ns
5.5 6.0 6.5 7.0 7.5 8.5 ns
Byte Write and Global Write
KQ
tCycle
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.
Curr (x18) 175 165 160 150 145 135 mA
Curr (x32/x36) 200 190 180 170 165 150 mA
3.3 V
2.5 V
Curr (x18) 175 165 160 150 145 135 mA
Curr (x32/x36) 200 190 180 170 165 150 mA
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.
Functional Description
Applications
The GS88018/32/36AT is a 9,437,184-bit (8,388,608-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.
Core and Interface Voltages
The GS88018/32/36AT 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
) pins are used to decouple output noise
DDQ
from the internal circuits and are 3.3 V and 2.5 V compatible.
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
Rev: 1.02 9/2002
1/26
© 2001, Giga Semiconductor, Inc.
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.