256K x 72, 512K x 36 and 1M x 18
18Mb, FLOW THROUGH 'NO WAIT'
STATE BUS SRAM
www.DataShee•t4U1.c0o0m percent bus utilization
• No wait cycles between Read and Write
• Internal self-timed write cycle
• Individual Byte Write Control
• Single Read/Write control pin
• Clock controlled, registered address,
data and control
• Interleaved or linear burst sequence control using
• Three chip enables for simple depth expansion
and address pipelining
• Power Down mode
• Common data inputs and data outputs
• CKE pin to enable clock and suspend operation
• JEDEC 100-pin TQFP, 165-ball PBGA and 209-
ball (x72) PBGA packages
• Power supply:
NVF: VDD 2.5V (± 5%), VDDQ 2.5V (± 5%)
NLF: VDD 3.3V (± 5%), VDDQ 3.3V/2.5V (± 5%)
• JTAG Boundary Scan for PBGA packages
• Industrial temperature available
• Lead-free available
The 18 Meg 'NLF/NVF' product family feature high-speed,
low-power synchronous static RAMs designed to provide
a burstable, high-performance, 'no wait' state, device for
networking and communications applications. They are
organized as 256K words by 72 bits, 512K words
by 36 bits and 1M words by 18 bits, fabricated with ISSI's
advanced CMOS technology.
Incorporating a 'no wait' state feature, wait cycles are
eliminated when the bus switches from read to write, or
write to read. This 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 are controlled
by a positive-edge-triggered single clock input. Operations
may be suspended and all synchronous inputs ignored
when Clock Enable, CKE is HIGH. In this state the internal
device will hold their previous values.
All Read, Write and Deselect cycles are initiated by the
ADV input. When the ADV is HIGH the internal burst
counter is incremented. New external addresses can be
loaded when ADV is LOW.
Write cycles are internally self-timed and are initiated by
the rising edge of the clock inputs and when WE is LOW.
Separate byte enables allow individual bytes to be written.
A burst mode pin (MODE) defines the order of the burst
sequence. When tied HIGH, the interleaved burst sequence
is selected. When tied LOW, the linear burst sequence is
FAST ACCESS TIME
6.5 7.5 Units
tKQ Clock Access Time 6.5 7.5 ns
tKC Cycle Time
7.5 8.5 ns
133 117 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. — www.issi.com — 1-800-379-4774