GS880E18/32/36CT-xxxV
100-Pin TQFP
Commercial Temp
Features
• FT pin for user-configurable flow through or pipeline
operation
• Dual Cycle Deselect (DCD) operation
• 1.8 V or 2.5 V +10%/–10% 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 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
• RoHS-compliant 100-lead TQFP package available
512K x 18, 256K x 32, 256K x 36
9Mb 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
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.
DCD Pipelined Reads
The GS880E18/32/36CT-xxxV is a DCD (Dual Cycle
Deselect) pipelined synchronous SRAM. SCD (Single Cycle
Deselect) versions are also available. DCD SRAMs pipeline
disable commands to the same degree as read commands. 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.
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 GS880E18/32/36CT-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.
Functional Description
Applications
The GS880E18/32/36CT-xxxV 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.
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
Parameter Synopsis
-250
Pipeline
3-1-1-1
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
3.0
4.0
175
200
5.5
5.5
135
155
-200
3.0
5.0
150
165
6.5
6.5
125
140
-150
3.8
6.7
125
145
7.5
7.5
113
125
Unit
ns
ns
mA
mA
ns
ns
mA
mA
Flow Through
2-1-1-1
Rev: 1.04 6/2012
1/23
© 2011, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GS880E18/32/36CT-xxxV
TQFP Pin Description
Symbol
A
0
, A
1
A
DQ
A
DQ
B
DQ
C
DQ
D
NC
BW
B
A
, B
B,
B
C
, B
D
CK
GW
E
1
, E
3
E
2
G
ADV
ADSP, ADSC
ZZ
FT
LBO
V
DD
V
SS
V
DDQ
Type
I
I
I/O
Description
Address field LSBs and Address Counter preset Inputs
Address Inputs
Data Input and Output pins
No Connect
Byte Write—Writes all enabled bytes; active low
Byte Write Enable for DQ
A
, DQ
B
Data I/Os; active low
Clock Input Signal; active high
Global Write Enable—Writes all bytes; active low
Chip Enable; active low
Chip Enable; active high
Output Enable; active low
Burst address counter advance enable; active low
Address Strobe (Processor, Cache Controller); active low
Sleep Mode control; active high
Flow Through or Pipeline mode; active low
Linear Burst Order mode; active low
Core power supply
I/O and Core Ground
Output driver power supply
—
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Rev: 1.04 6/2012
5/23
© 2011, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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