IS61(64)LF25636B, IS61VF/VVF25636B
IS61(64)LF51218B, IS61VF/VVF51218B
256K x 36, 512K x 18
9 Mb SYNCHRONOUS
FLOW-THROUGH
STATIC RAM
FEATURES
• Internal self-timed write cycle
• Individual Byte Write Control and Global Write
• Clock controlled, registered address, data and
control
• Burst sequence control using MODE input
• Three chip enable option for simple depth expan-
sion and address pipelining
• Common data inputs and data outputs
• Auto Power-down during deselect
• Single cycle deselect
• Snooze MODE for reduced-power standby
• JTAG Boundary Scan for BGA package
• Power Supply
LF: Vdd
3.3V (+
5%), Vddq
3.3V/2.5V (+
5%)
VF: Vdd
2.5V (+
5%), Vddq
2.5V (+
5%)
VVF: Vdd
1.8V (+
5%), Vddq
1.8V (+
5%)
• JEDEC 100-Pin QFP, 119-pin BGA, and 165-pin
BGA packages
• Lead-free available
MARCH 2020
DESCRIPTION
The 9Mb product family features high-speed, low-power
synchronous static RAMs designed to provide burstable,
high-performance memory for communication and network-
ing applications. The IS61(64)LF/VF25636B
is organized
as 262,144 words by 36 bits. The IS61(64)LF/VF51218B
is organized as 524,288 words by 18 bits. Fabricated with
ISSI
's advanced CMOS technology, the device integrates
a 2-bit burst counter, high-speed SRAM core, and high-
drive capability outputs into a single monolithic circuit. All
synchronous inputs pass through registers controlled by
a positive-edge-triggered single clock input.
Write cycles are internally self-timed and are initiated by the
rising edge of the clock input. Write cycles can be one to
four bytes wide as controlled by the write control inputs.
Separate byte enables allow individual bytes to be writ-
ten. Byte write operation is performed by using byte write
enable (BWE)
input combined with one or more individual
byte write signals (BWx). In addition, Global Write (GW)
is available for writing all bytes at one time, regardless of
the byte write controls.
Bursts can be initiated with either
ADSP
(Address Status
Processor) or
ADSC
(Address Status Cache Controller)
input pins. Subsequent burst addresses can be gener-
ated internally and controlled by the
ADV
(burst address
advance) input pin.
The mode pin is used to select the burst sequence order,
Linear burst is achieved when this pin is tied LOW. Inter-
leave burst is achieved when this pin is tied HIGH or left
floating.
FAST ACCESS TIME
Symbol
tkq
tkc
Parameter
Clock Access Time
Cycle Time
Frequency
-6.5
6.5
7.5
133
-7.5
7.5
8.5
117
Units
ns
ns
MHz
Copyright © 2020 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no
liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on
any published information and before placing orders for products.
Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause
failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written
assurance to its satisfaction, that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
Integrated Silicon Solution, Inc. — www.issi.com —
1-800-379-4774
Rev. B2
03/04/2020
1
IS61(64)LF25636B, IS61VF/VVF25636B
IS61(64)LF51218B, IS61VF/VVF51218B
119 BGA PACKAGE PIN CONFIGURATION-
256K x 36 (TOP VIEW)
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
V
DDQ
NC
NC
DQc
DQc
V
DDQ
DQc
DQc
V
DDQ
DQd
DQd
V
DDQ
DQd
DQd
NC
NC
V
DDQ
2
A
CE2
A
DQPc
DQc
DQc
DQc
DQc
V
DD
DQd
DQd
DQd
DQd
DQPd
A
NC
TMS
3
A
A
A
Vss
Vss
Vss
BWc
Vss
NC
Vss
BWd
Vss
Vss
Vss
MODE
A
TDI
4
ADSP
ADSC
V
DD
NC
CE
OE
ADV
GW
V
DD
CLK
NC
BWE
A
1
*
A
0
*
V
DD
A
TCK
5
A
A
A
Vss
Vss
Vss
BWb
Vss
NC
Vss
BWa
Vss
Vss
Vss
NC
A
TDO
6
A
A
A
DQPb
DQb
DQb
DQb
DQb
V
DD
DQa
DQa
DQa
DQa
DQPa
A
NC
NC
7
V
DDQ
NC
NC
DQb
DQb
V
DDQ
DQb
DQb
V
DDQ
DQa
DQa
V
DDQ
DQa
DQa
NC
ZZ
V
DDQ
Note:
* A
0
and A
1
are the two least significant bits (LSB) of the address field and set the internal burst counter if burst is desired.
PIN DESCRIPTIONS
Symbol
A
A0, A1
ADV
ADSP
ADSC
GW
CLK
CE,
CE2
BWx
(x=a-d)
BWE
Pin Name
Address Inputs
Synchronous Burst Address Inputs
Synchronous Burst Address
Advance
Address Status Processor
Address Status Controller
Global Write Enable
Synchronous Clock
Synchronous Chip Select
Synchronous Byte Write Controls
Byte Write Enable
Symbol
OE
ZZ
MODE
TCK, TDO
TMS, TDI
NC
DQa-DQd
DQPa-Pd
Vdd
Vddq
Vss
No Connect
Data Inputs/Outputs
Parity Data Inputs/Outputs
Power Supply
I/O Power Supply
Ground
Pin Name
Output Enable
Power Sleep Mode
Burst Sequence Selection
JTAG Pins
4
Integrated Silicon Solution, Inc. — www.issi.com —
1-800-379-4774
Rev. B2
03/04/2020
IS61(64)LF25636B, IS61VF/VVF25636B
IS61(64)LF51218B, IS61VF/VVF51218B
119 BGA PACKAGE PIN CONFIGURATION
512Kx18 (TOP VIEW)
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
V
DDQ
NC
NC
DQb
NC
V
DDQ
NC
DQb
V
DDQ
NC
DQb
V
DDQ
DQb
NC
NC
NC
V
DDQ
2
A
CE2
A
NC
DQb
NC
DQb
NC
V
DD
DQb
NC
DQb
NC
DQPb
A
A
TMS
3
A
A
A
Vss
Vss
Vss
BWb
Vss
NC
Vss
Vss
Vss
Vss
Vss
MODE
A
TDI
4
ADSP
ADSC
V
DD
NC
CE
OE
ADV
GW
V
DD
CLK
NC
BWE
A
1
*
A
0
*
V
DD
NC
TCK
5
A
A
A
Vss
Vss
Vss
Vss
Vss
NC
Vss
BWa
Vss
Vss
Vss
NC
A
TDO
6
A
A
A
DQPa
NC
DQa
NC
DQa
V
DD
NC
DQa
NC
DQa
NC
A
A
NC
7
V
DDQ
NC
NC
NC
DQa
V
DDQ
DQa
NC
V
DDQ
DQa
NC
V
DDQ
NC
DQa
NC
ZZ
V
DDQ
Note:
* A
0
and A
1
are the two least significant bits (LSB) of the address field and set the internal burst counter if burst is desired.
PIN DESCRIPTIONS
Symbol
A
A0, A1
ADV
ADSP
ADSC
GW
CLK
CE,
CE2
BWx
(x=a,b)
BWE
Pin Name
Address Inputs
Synchronous Burst Address Inputs
Synchronous Burst Address
Advance
Address Status Processor
Address Status Controller
Global Write Enable
Synchronous Clock
Synchronous Chip Select
Synchronous Byte Write Controls
Byte Write Enable
Symbol
OE
ZZ
MODE
TCK, TDO
TMS, TDI
NC
DQa-DQb
DQPa-Pb
Vdd
Vddq
Vss
No Connect
Data Inputs/Outputs
Parity Data Inputs/Outputs
Power Supply
I/O Power Supply
Ground
Pin Name
Output Enable
Power Sleep Mode
Burst Sequence Selection
JTAG Pins
Integrated Silicon Solution, Inc. — www.issi.com —
1-800-379-4774
Rev. B2
03/04/2020
5