Preliminary
GS8641EV18/32/36F-300/250/200/167
165-Bump BGA
Commercial Temp
Industrial Temp
Features
• FT pin for user-configurable flow through or pipeline
operation
• Dual Cycle Deselect (DCD) operation
• IEEE 1149.1 JTAG-compatible Boundary Scan
• 1.8 V +10%/–10% core power supply
• 1.8 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 165-bump FP-BGA package
• Pb-Free 165-bump BGA package available
4M x 18, 2M x 32, 2M x 36
72Mb Sync Burst SRAMs
300 MHz–167 MHz
1.8 V V
DD
1.8 V I/O
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 GS8641EV18/32/36F 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 GS8641EV18/32/36F operates on a 1.8 V power supply.
All input are 1.8 V compatible. Separate output power (V
DDQ
)
pins are used to decouple output noise from the internal circuits
and are 1.8 V compatible.
Functional Description
Applications
The GS8641EV18/32/36F is a 75,497,472-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
Parameter Synopsis
-300
2.3
3.3
400
480
5.5
5.5
285
330
-250
2.5
4.0
340
410
6.5
6.5
245
280
-200
3.0
5.0
290
350
7.5
7.5
220
250
-167
3.5
6.0
260
305
8.0
8.0
210
240
Unit
ns
ns
mA
mA
ns
ns
mA
mA
Pipeline
3-1-1-1
Flow
Through
2-1-1-1
t
KQ
tCycle
Curr
(x18)
Curr
(x32/x36)
t
KQ
tCycle
Curr
(x18)
Curr
(x32/x36)
Rev: 1.01 3/2005
1/29
© 2004, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
Preliminary
GS8641EV18/32/36F-300/250/200/167
GS8641EV18/32/36F 165-Bump 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
NC
CK
BW
GW
E
1
E
3
E
2
G
ADV
ADSC, ADSP
ZZ
FT
LBO
TMS
TDI
TDO
TCK
MCL
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
O
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
Chip Enable; active low
Chip Enable; active low
Chip Enable; active high
Output Enable; active low
Burst address counter advance enable; active l0w
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
Scan Test Mode Select
Scan Test Data In
Scan Test Data Out
Scan Test Clock
Must Connect Low
Core power supply
I/O and Core Ground
Output driver power supply
Rev: 1.01 3/2005
5/29
© 2004, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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