GS88237BB-333/300/250/200
119-Bump BGA
Commercial Temp
Industrial Temp
Features
• Single/Dual Cycle Deselect selectable
• IEEE 1149.1 JTAG-compatible Boundary Scan
• 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-bump BGA packages
• RoHS-compliant 119-bump BGA packages available
256K x 36
9Mb SCD/DCD Sync Burst SRAM
333 MHz–200 MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
SCD and DCD Pipelined Reads
The GS88237BB 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 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.
FLXDrive™
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
The GS88237BB 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.
Functional Description
Applications
The GS88237BB 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.
Controls
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 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.
N
ot
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Parameter Synopsis
Pipeline
3-1-1-1
3.3 V
2.5 V
t
KQ
tCycle
Curr
(x36)
Curr
(x36)
-333
2.0
3.0
435
435
-300
2.2
3.3
395
395
-250
2.3
4.0
330
330
-200 Unit
2.7
ns
5.0
ns
270
270
mA
mA
Rev: 1.06a 12/2008
1/26
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ew
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es
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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n
© 2002, GSI Technology
GS88237BB-333/300/250/200
GS88237 BGA Pin Description
Symbol
A
0
, A
1
A
DQ
A
DQ
B
DQ
C
DQ
D
B
A
, B
B
, B
C
, B
D
DNU
NC
CK
BW
GW
E
1
E
3
E
2
G
ADV
ADSC, ADSP
ZZ
LBO
PE
ZQ
TMS
TDI
TDO
TCK
V
DD
V
SS
V
DDQ
SCD
Type
I
I
I/O
I
—
—
I
I
I
I
I
I
I
I
I
I
I
I
I
Description
Address field LSBs and Address Counter Preset Inputs
Address Inputs
Data Input and Output pins
Byte Write Enable for DQ
A
, DQ
B
, DQ
C
, DQ
D
I/Os; active low
No Connect
Clock Input Signal; active high
Byte Write—Writes all enabled bytes; active low
Global Write Enable—Writes all bytes; active low
en
de
Address Strobe (Processor, Cache Controller); active low
Sleep mode control; active high
Linear Burst Order mode; active low
9th Bit Enable; active low (only on 119-bump BGA)
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om
FLXDrive Output Impedance Control (Low = Low Impedance [High Drive], High = High Impedance [Low
Drive])
Scan Test Mode Select
Scan Test Data In
Scan Test Data Out
Scan Test Clock
Single Cycle Deselect/Dual Cyle Deselect Mode Control
Core power supply
I/O and Core Ground
Output driver power supply
I
O
I
N
—
I
I
I
Rev: 1.06a 12/2008
m
3/26
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Burst address counter advance enable; active l0w
fo
r
Chip Enable; active high
Output Enable; active low
N
Chip Enable; active low
Chip Enable; active low
ew
D
© 2002, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
es
Do Not Use
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GS88237BB-333/300/250/200
Mode Pin Functions
Mode Name
Burst Order Control
Output Register Control
Power Down Control
Single/Dual Cycle Deselect Control
FLXDrive Output Impedance Control
9th Bit Enable
Pin Name
LBO
FT
ZZ
SCD
ZQ
PE
State
L
H
L
H or NC
L or NC
H
L
H or NC
L
H or NC
L or NC
H
Function
Linear Burst
Interleaved Burst
Flow Through
Pipeline
Active
Burst Counter Sequences
1st address
2nd address
3rd address
4th address
00
01
10
11
01
10
11
10
11
en
A[1:0] A[1:0] A[1:0] A[1:0]
11
de
Linear Burst Sequence
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r
Note:
There is a are pull-up devices on the ZQ, SCD, and FT pins and a pull-down device on the ZZ pin, so thosethis input pins can be
unconnected and the chip will operate in the default states as specified in the above tables.
Interleaved Burst Sequence
A[1:0] A[1:0] A[1:0] A[1:0]
1st address
2nd address
3rd address
4th address
00
01
10
11
01
00
11
10
10
11
00
01
11
10
01
00
om
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ot
R
Note:
The burst counter wraps to initial state on the 5th clock.
ec
00
m
00
01
10
00
01
Note:
The burst counter wraps to initial state on the 5th clock.
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ew
D
Activate DQPx I/Os (x18/x3672 mode)
Deactivate DQPx I/Os (x16/x3272 mode)
es
High Drive (Low Impedance)
Low Drive (High Impedance)
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n
Standby, I
DD
= I
SB
Dual Cycle Deselect
Single Cycle Deselect
BPR 1999.05.18
Rev: 1.06a 12/2008
5/26
© 2002, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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