GS88218/36BB/D-250/225/200/166/150/133
119- and 165-Bump BGA
Commercial Temp
Industrial Temp
Features
512K x 18, 256K x 36
9Mb SCD/DCD Sync Burst SRAMs
Flow Through/Pipeline Reads
250 MHz–133MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
• FT pin for user-configurable flow through or pipeline operation
• Single/Dual Cycle Deselect selectable
• IEEE 1149.1 JTAG-compatible Boundary Scan
• On-chip read parity checking; even or odd selectable
• ZQ mode pin for user-selectable high/low output drive
• 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 SCD x18/x36 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 119- and 165-bump BGA packages
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.
The function of the Data Output register can be controlled by the
user via the FT mode . 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 and DCD Pipelined Reads
Pipeline
3-1-1-1
3.3 V
2.5 V
Flow
Through
2-1-1-1
3.3 V
2.5 V
t
KQ
tCycle
Curr
(x18)
Curr
(x32/x36)
Curr
(x18)
Curr
(x32/x36)
t
KQ
tCycle
Curr
(x18)
Curr
(x32/x36)
Curr
(x18)
Curr
(x32/x36)
-250 -225 -200 -166 -150 -133 Unit
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
280
330
275
320
5.5
5.5
175
200
175
200
255
300
250
295
6.0
6.0
165
190
165
190
230
270
230
265
6.5
6.5
160
180
160
180
200
230
195
225
7.0
7.0
150
170
150
170
185
215
180
210
7.5
7.5
145
165
145
165
165
190
165
185
8.5
8.5
135
150
135
150
mA
mA
mA
mA
ns
ns
mA
mA
mA
mA
The GS88218/36B is a SCD (Single Cycle Deselect) and DCD
(Dual Cycle Deselect) pipelined synchronous SRAM. DCD
SRAMs pipeline disable commands to the same degree as read
commands. 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. 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. The user may
configure this SRAM for either mode of operation using the SCD
mode input.
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.
Byte Write and Global Write
FLXDrive™
Functional Description
Applications
The GS88218/36B 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.
Addresses, data I/Os, chip enable (E1), 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
The ZQ pin allows selection between high drive strength (ZQ low)
for multi-drop bus applications and normal drive strength (ZQ
floating or high) point-to-point applications. See the Output Driver
Characteristics chart for details.
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
Controls
The GS88218/36B 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.
Rev: 1.00b 12/2002
1/33
© 2001, Giga Semiconductor, Inc.
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
ByteSafe is a Trademark of Giga Semiconductor, Inc. (GSI Technology).
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