GS880E18/32/36BT-333/300/250/200/150
100-Pin TQFP
Commercial Temp
Industrial Temp
Features
• FT pin for user-configurable flow through or pipeline
operation
• Dual Cycle Deselect (DCD) 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
• 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
• Pb-Free 100-lead TQFP package available
512K x 18, 256K x 32, 256K x 36
9Mb Sync Burst SRAMs
250 MHz–150 MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
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 GS880E18/32/36BT 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 GS880E18/32/36BT 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 GS880E18/32/36BT 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
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.
-333
Pipeline
3-1-1-1
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
2.5
3.0
250
290
4.5
4.5
200
230
Paramter Synopsis
-300
2.5
3.3
230
265
5.0
5.0
185
210
-250
2.5
4.0
200
230
5.5
5.5
160
185
-200
3.0
5.0
170
195
6.5
6.5
140
160
-150
3.8
6.7
140
160
7.5
7.5
128
145
Unit
ns
ns
mA
mA
ns
ns
mA
mA
Flow Through
2-1-1-1
Rev: 1.02 10/2004
1/28
© 2001, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GS880E18/32/36BT-333/300/250/200/150
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
—
I
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
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
Rev: 1.02 10/2004
5/28
© 2001, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
Embedded System
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