GS88218/36B(B/D)-xxxV
119- and 165-Bump BGA
Commercial Temp
Industrial Temp
Features
• 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
• 1.8 V or 2.5 V core power supply
• 1.8 V or 2.5 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
• RoHS-compliant packages available
512K x 18, 256K x 36
9Mb SCD/DCD Sync Burst SRAMs
250 MHz–150 MHz
1.8 V or 2.5 V V
DD
1.8 V or 2.5 V I/O
Data Output Register. Holding FT high places the RAM in
Pipeline mode, activating the rising-edge-triggered Data Output
Register.
Functional Description
Applications
The GS88218/36B(B/D)-xxxV 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.
Flow Through/Pipeline Reads
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
N
ot
R
SCD and DCD Pipelined Reads
The
GS88218/36B(B/D)-xxxV
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
GS88218/36B(B/D)-xxxV
operates on a 1.8 V or 2.5 V
power supply. All input are 2.5 V and 1.8 V compatible.
Separate output power (V
DDQ
) pins are used to decouple
output noise from the internal circuits and are 2.5 V and 1.8 V
compatible.
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Paramter Synopsis
-250
-200
3.0
5.0
170
195
6.5
6.5
140
160
d
fo
r
3.0
4.0
200
230
5.5
5.5
160
185
N
ew
-150
3.8
6.7
140
160
7.5
7.5
128
145
Pipeline
3-1-1-1
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
Flow Through
2-1-1-1
Rev: 1.04a 9/2008
1/34
D
Unit
ns
ns
mA
mA
ns
ns
mA
mA
es
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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