Preliminary
GS880F18/36T-10/11/11.5/12/14
100 Pin TQFP
Commercial Temp
Industrial Temp
Features
• Flow through mode operation.
• 3.3V +10%/-5% Core power supply.
• 2.5V or 3.3V I/O supply.
• LBO pin for linear or interleaved burst mode.
• Internal input resistors on mode pins allow floating mode pins.
Default to Interleaved Pipelined Mode.
• Byte write (BW) and/or global write (GW) operation.
• Common data inputs and data outputs.
• Clock Control, registered, address, data, and control.
• Internal Self-Timed Write cycle.
• Automatic power-down for portable applications.
• 100-lead TQFP package
-10
-11
-11.5
-12
-14
10ns 11ns 11.5ns 12ns 14ns
Flow Through t
KQ
2-1-1-1
tCycle 10ns 15ns 15ns 15ns 15ns
I
DD
225mA 180mA 180mA 180mA 175mA
512K x 18, 256K x 36
8Mb Sync Burst SRAMs
10ns - 14ns
3.3V VDD
3.3V & 2.5V I/O
broadest access to multiple vendor sources. Boards designed with FT
pin pads tied low may be stuffed with GSI’s Pipeline/Flow through
configurable Burst RAMS or any vendor’s Flow through or
configurable Burst SRAM. Bumps designed with the FT pin location
tied High or floating must employ a non-configurable Flow through
Burst RAM, like this RAM, to achieve Flow through functionality.
88018/32/36T
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 GS880F18/32/36T operates on a 3.3V power supply and all
inputs/outputs are 3.3V and 2.5V compatible. Separate output power
(V
DDQ
) pins are used to de-couple output noise from the internal
circuit.
Functional Description
Applications
The GS880F18/32/36T is a 9,437,184 bit (8,388,608 bit for x32
version) 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 CPU’s, the device
now finds application in synchronous SRAM applications ranging from
DSP main store to networking chip set support.
Controls
Addresses, data I/O’s, chip enables (E1, E2, E3), 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 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.
Designing For Compatibility
The JEDEC Standard for Burst RAMS calls for a FT mode pin option
(pin 14 on TQFP). Board sites for Flow through Burst RAMS should
be designed with V
SS
connected to the FT pin location to ensure the
Rev: 1.03 3/2000
1/25
© 2000, Giga Semiconductor, Inc.
N
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GSI [ GSI TECHNOLOGY ]
