GS88018T Datasheet, PDF (1/25 Pages) GSI Technology – 512K x 18, 256K x 32, 256K x 36 8Mb Sync Burst SRAMs

Preliminary
GS88018/32/36T-11/11.5/100/80/66
100-Pin TQFP
Commercial Temp
Industrial Temp
512K x 18, 256K x 32, 256K x 36 ^{100 MHz–66 MHz}
8Mb Sync Burst SRAMs
3.3 V V_DD
3.3 V and 2.5 V I/O
Features
• FT pin for user-configurable flow through or pipelined
operation
• Single Cycle Deselect (SCD) operation
• 3.3 V +10%/–5% core power supply
• 2.5 V or 3.3 V 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
Pipeline
3-1-1-1
Flow
Through
2-1-1-1
-11 -11.5 -100 -80 -66
tCycle 10 ns 10 ns 10 ns 12.5 ns 15 ns
t_KQ 4.0 ns 4.0 ns 4.0 ns 4.5 ns 5 ns
I_DD ^{225 mA 225 mA 225 mA 200 mA 185 mA}
t_KQ 11 ns 11.5 ns 12 ns 14 ns 18 ns
tCycle ^{15 ns 15 ns 15 ns 15 ns 20 ns}
I_DD ^{180 mA 180 mA 180 mA 175 mA 165 mA}
Functional Description
Applications
The GS88018/32/36T 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
CPUs, the device now finds application in synchronous SRAM
applications, ranging from DSP main store to networking chip
set support.
Controls
Addresses, data I/Os, 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.
Flow Through/Pipeline Reads
The function of the Data Output Register can be controlled by
the user via the FT mode pin (Pin 14). Holding the FT mode
pin low places the RAM in Flow Through mode, causing
output data to bypass the Data Output Register. Holding FT
high places the RAM in Pipeline mode, activating the rising-
edge-triggered Data Output Register.
SCD Pipelined Reads
The GS88018/32/36T is a SCD (Single Cycle Deselect)
pipelined synchronous SRAM. DCD (Dual Cycle Deselect)
versions are also available. SCD SRAMs pipeline deselect
commands one stage less than read commands. SCD RAMs
begin turning off their outputs immediately after the deselect
command has been captured in the input registers.
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 GS88018/32/36T operates on a 3.3 V power supply and all
inputs/outputs are 3.3 V- and 2.5 V-compatible. Separate
output power (V_DDQ) pins are used to decouple output noise
from the internal circuit.
Rev: 1.11 8/2000
1/25
© 2000, Giga Semiconductor, Inc.
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.