VPS102418A are high-speed, low-power synchronous static
RAMs designed to provide burstable, high-performance memory
for communication and networking applications. The
IS61LPS/VPS51236A is organized as 524,288 words by 36
bits, and the IS61LPS/VPS102418A is organized as
1,048,576 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
This document contains ADVANCE INFORMATION data. ISSI reserves the right to make changes to its products at any time without notice in order to improve design and supply the best
