IS61VPS25636A IS61LPS25636A
IS61VPS51218A IS61LPS51218A
256K x 36, 512K x 18
9 Mb SYNCHRONOUS PIPELINED,
SINGLE CYCLE DESELECT 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
expansion 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 PBGA package
• Power Supply
LPS: V
DD
3.3V + 5%, V
DDQ
3.3V/2.5V + 5%
VPS: V
DD
2.5V + 5%, V
DDQ
2.5V + 5%
• JEDEC 100-Pin TQFP, 119-ball PBGA, and
165-ball PBGA packages
• Lead-free available
ISSI
MAY 2005
®
DESCRIPTION
The
ISSI
IS61LPS/VPS25636A and IS61LPS/
VPS51218A are high-speed, low-power synchronous static
RAMs designed to provide burstable, high-performance memory
for communication and networking applications. The
IS61LPS/VPS25636A is organized as 262,144 words by
36 bits and the IS61LPS/VPS51218A is organized as
524,288 words by 18 bits. Fabricated with
ISSI
's ad-
vanced 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 written.
The byte write operation is performed by using the 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 generated
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.
Interleave burst is achieved when this pin is tied HIGH or
left floating.
FAST ACCESS TIME
Symbol
t
KQ
t
KC
Parameter
Clock Access Time
Cycle Time
Frequency
250
2.6
4
250
200
3.1
5
200
Units
ns
ns
MHz
Copyright © 2005 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. — 1-800-379-4774
Rev. A
04/29/05
1
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
