144Mbit SigmaQuadTM and SigmaDDRTM
FAQ
Q) What are the different types of devices that make up the
144Mbit SigmaQuadTM and SigmaDDRTM family?
A)
This 144Mbit fast SRAM family consists of four groups of products.
|
|
Separate I/O |
Common I/O |
|
Type-II |
SigmaQuad-II |
SigmaDDR-II |
|
Type-II+ |
SigmaQuad-II+ |
SigmaDDR-II+ |
The
Type-II devices are density upgrades to Type-II Quad and DDR SRAMs that have
been on the market for several years. The Type-II+ devices, designed for
somewhat higher speeds, are density upgrades to the more recently introduced
Type-II+ products. As noted in the table above, both types are offered in both
Common I/O (DDR) and Separate I/O (Quad) versions.
Q) What are the different types of devices that make up the
144Mbit SigmaQuad-II+ and SigmaDDR-II+
family?
A)
The 144Mbit Type-II+ family of SRAMs consists of two different types of high
speed SRAM products. One is a SigmaDDR (Double Data
Rate) Common I/O (CIO) SRAM configured for Burst of 2 operations. The other is
a SigmaQuad SRAM Separate I/O (SIO) SRAM configured
for Burst of 4 operations. There are also two different Read Latency (RL)
configurations available. Both of the Type–II+ versions include On-Die
Termination (ODT).
|
Density |
Type |
Burst |
RL |
Speed |
Part
Number |
Package |
|
144Mbit |
SigmaQuad-II+ |
4 |
2.0 |
400–300 |
GS81302D07E/GE-xxx |
15 mm x 17 mm FBGA |
|
GS81302D10E/GE-xxx |
||||||
|
GS81302D19E/GE-xxx
|
||||||
|
GS81302D37E/GE-xxx |
||||||
|
SigmaDDR-II+ |
2 |
2.0 |
400–300 |
GS81302T07E/GE-xxx |
||
|
GS81302T10E/GE-xxx |
||||||
|
GS81302T19E/GE-xxx |
||||||
|
GS81302T37E/GE-xxx |
||||||
|
SigmaQuad-II+ |
4 |
2.5 |
450–300 |
GS81302D06E/GE-xxx |
||
|
GS81302D11E/GE-xxx |
||||||
|
GS81302D20E/GE-xxx |
||||||
|
GS81302D38E/GE-xxx |
||||||
|
SigmaDDR-II+ |
2 |
2.5 |
450–300 |
GS81302T06E/GE-xxx |
||
|
GS81302T11E/GE-xxx |
||||||
|
GS81302T20E/GE-xxx |
||||||
|
GS81302T38E/GE-xxx |
The
SigmaQuad-II+ and SigmaDDR-II+
families of high speed SRAM are pin and function compatible with other Type II+
devices and are available in multiple organizations and speed bins. Both types
can be used to upgrade current designs or used in new designs that require
higher speeds.
Q) What are some of the features of SigmaQuad-II+
and SigmaDDR-II+ 144Mbit
Family?
A)
The 144Mbit family of SigmaQuad-II+ and SigmaDDR-II+ SRAMs achieve higher operating frequencies, in
part, because they are designed with a longer read pipeline. When described in
terms of cycles of latency, Type-II SRAMs demonstrate a 1.5 cycle read latency,
while Type-II+ SRAMs are offered with read latencies of both 2.0 and 2.5
cycles. The multiple read latency selections offered allow designers more
flexibility to optimize SRAM performance in their particular applications.
Type-II+
SRAMs also offer optional On-Die Termination (ODT) to improve signal integrity.
ODT can be enabled or disabled via the ODT pin—a Low (0) disables ODT while a High
(1) enables ODT. When ODT is enabled, a resistor (RQ) connected between pin ZQ
and ground sets the input termination impedance. The device supports an RQ
value of 175 to 350 ohms in order to produce a Thevenin-equivalent
termination impedance of RQ*0.6 with an accuracy of ±15%.
Like
all SigmaQuad/SigmaDDR
SRAMs, these devices also include FLXDrive-II output
impedance control. The same ZQ pin and external RQ resistor used to program
input impedance is also used to program output driver impedance. These SRAMs
support an RQ resistor value of 175 to 350 ohms, and will deliver an output
impedance of RQ/5, within an accuracy of ±15%.
Type-II+
SRAMs also offer an Output Valid signal (QVLD), that provides early warning of
impending valid data and is used to facilitate synchronization of RAM data with
the clock domain of the host chip using the SRAM.
Q) What are the different types of devices that make up the SigmaQuad-II and
SigmaDDR-II family of 144Mbit SRAMs?
A)
The 144Mbit Type-II family of SRAMs consists of five different types of high
speed SRAM products. Two are SigmaDDR-II (Double Data
Rate) SRAMs with Common I/O (CIO). In this group, one set is configured for Burst
of 2 operations and the other for Burst of 4 operations. A third member of this
group is a hybrid device offering Burst of 2 DDR operations in a Separate I/O (SIO)
pinout. The other SRAMs in the family are the SigmaQuad-II SRAMs. These devices are Separate I/O (SIO)
devices and are offered in both Burst of 2 and Burst of 4 versions.
Density |
Type |
Burst |
Speed |
Part
Number |
Package |
|
144Mbit |
SigmaQuad-II |
4 |
333–167 |
GS81302D08E/GE-xxx |
15 mm x 17 mm FBGA |
|
GS81302D09E/GE-xxx |
|||||
|
GS81302D18E/GE-xxx |
|||||
|
GS81302D36E/GE-xxx |
|||||
|
SigmaQuad-II |
2 |
250–167 |
GS81302Q08E/GE-xxx |
||
|
GS81302Q09E/GE-xxx
|
|||||
|
GS81302Q18E/GE-xxx |
|||||
|
GS81302Q36E/GE-xxx |
|||||
|
SigmaDDR-II |
4 |
333–167 |
GS81302R08E/GE-xxx |
||
|
GS81302R09E/GE-xxx |
|||||
|
GS81302R18E/GE-xxx |
|||||
|
GS81302R36E/GE-xxx |
|||||
|
SigmaDDR-II |
2 |
333–167 |
GS81302T08E/GE-xxx |
||
|
GS81302T09E/GE-xxx |
|||||
|
GS81302T18E/GE-xxx |
|||||
|
GS81302T36E/GE-xxx |
|||||
|
SigmaDDR-II
SIO |
2 |
333–167 |
GS81302S08E/GE-xxx |
||
|
GS81302S09E/GE-xxx |
|||||
|
GS81302S18E/GE-xxx |
|||||
|
GS81302S36E/GE-xxx |
SigmaQuad-II
devices are pin and function compatible with other Type-II SRAMs. They are available
in multiple speed bins—from 167 MHz to 333 MHz in Burst of 4 configurations and
167 MHz to 250 MHz in Burst of 2 configurations.
SigmaDDR-II
devices have a common data bus and are supplied in both Burst of 2 and
Burst of 4 versions. They are available
in I/O widths of 8, 9, 18 and 36 with multiple speed
bins—from 167 MHz to 333 MHz
SigmaDDR-II
SIO devices separate data input and data output pins like the Quad SRAMs but
can do continuous Read or Write operations. They are available in Burst of 2
configuration with I/O widths of 8, 9, 18 and 36 in multiple speed bins—from
167 MHz to 333 MHz.
Q) Why is GSI offering 144Mbit densities for the SigmaQuad/SigmaDDR-II family?
A)
GSI’s 144Mbit offering is intended to continue to improve the value and
performance available to SRAM users world wide. The
products provide a direct density upgrade for existing applications currently
using 18Mbit through 72Mbit products that need maximum density and performance.
The family is a solid next step in the long term support of this class of
memory.
Q) When will 144Mbit parts be available?
A)
Engineering samples are available now. Please contact your local GSI Sales
representative for pricing and delivery. Datasheets are available at www.gsitechnology.com
Q) Are GSI’s 144Mbit devices drop-in replacements for other
Quad and DDR SRAMs?
A)
The basic operation and truth tables are the same for both Type-II+ and Type-II
parts. But, as these are higher density SRAMs, additional address signals are
required when upgrading a design from lower densities to 144Mbit. The 72Mbit to
144Mbit upgrade address pin location is ball A2 on the package for SigmaDDR-II + CIO devices. For SigmaQuad-II
+ parts, the upgrade address ball location is A10. The JTAG TAP has been
standardized so the only differences from previous generation JTAG TAP
registers in the product are in the company specific IDCODE field that
indicates device revision.
Q)
Is there a different package for the 144Mbit versus lower density parts?
A)
GSI uses the JEDEC-standard 165-bump Fine Pitch BGA array for all SigmaQuad and SigmaDDR SRAMs. The
package perimeter matches that used since 36Mb devices were introduced and
measures 15 mm x 17 mm.
Q)
Are the 144Mbit families offered in a lead-free package?
A)
Yes, 144Mbit family and virtually all GSI products are offered in both 5/6 RoHS-compliant leaded package and 6/6 RoHS-compliant
lead-free package.
Q)
In what temperature ranges are the GSI 144Mbit devices offered?
A)
GSI offers Commercial Temp (0°C to+70°C), Industrial Temp (–40°C to+85°C)
temperature ranges for all part numbers in its product line. Extended
temperature and Military temperature parts are also available in all product
families.
Q)
What are some applications in which SigmaQuad/DDR
devices are used?
A)
SigmaQuad and SigmaDDR
devices are primarily used in networking applications in support of Network
Processors, FPGAs and ASICs, but also see service in image processing (medical
and military), high speed data acquisition, test equipment, and various other
fields. Typical types of networking applications include:
SigmaQuad—Packet
buffering and statistics accumulation
SigmaDDR—Table
look-ups, translation tables, and general purpose memory storage