AMCC Components Provide Breakthrough Performance Enhancement in Fibre
Channel RAID Subsystems
Business Wire - October 27, 1997 07:58
-- Jitter peaking performance of repeater improved by 300 percent
over competitive solutions for better data signal integrity
SAN DIEGO--(BUSINESS WIRE)--Oct. 27, 1997--Applied Micro Circuits Corp.
(AMCC) Monday announced a Port Bypass Circuit (PBC) and Port Bypass with
Repeater Circuit for use in 1.0625 gigabit/second (Gb/s) Fibre Channel Arbitrated
Loop (FC-AL) Disk Arrays, a high performance RAID subsystem that is rapidly
gaining acceptance.
The S2058 Port Bypass with Repeater is designed with a jitter peaking specification of
0.1dB, less than one-third of previously available solutions.
AMCC's S2057 PBC and S2058 Port Bypass with Repeater Circuit are important
building blocks used in FC-AL RAID subsystems. Typical FC RAID arrays can
support from four to 24 disk drives, and have a drive connector available for each.
One PBC is required for each drive node, and use of a Port Bypass with Repeater
instead of the standard PBC is recommended at every fifth or sixth node.
"We've designed the first 1.0625 Gb/s FC single-port bypass circuit to simplify the
design of disk drive backplane boards for Fibre Channel RAID systems, minimize EMI
by reducing trace length, and reduce jitter accumulation," said Jack Basi, director of
marketing, datacom and computer products, at AMCC.
"To reduce cost, all of the previously available PBC's were designed with four ports
per chip. In practice, this results in long trace lengths needed to bring the circuitry from
the chip to four separate port connectors. Our single-port S2057 is approximately
one-third inch square, and can fit between the disk drive connectors, thus minimizing
trace length and the associated EMI. The pinout has been planned so that the layout
designer needs no vias or discontinuities in interconnection while connecting the PBC
between two port connectors."
The S2057 is a PBC designed to reduce jitter accumulation to less than 10ps by
providing a high bandwidth fully differential signal path. PBC's are used within FC-AL
disk arrays to provide resiliency and hot swapping of FC-AL drives. A PBC is a 2:1
multiplexer with two modes of operation, Normal and Bypass. In Normal mode, the
disk drive is connected to the loop. In Bypass mode, the disk drive is either absent or
non-functional and data bypasses to the next available disk drive.
The S2058 Port Bypass with Repeater performs two functions. The first is to perform
the function of a PBC for nodes in a FC-AL system. The low jitter accumulation of the
port bypass path is essential in these systems. The second function is to retime and
restore signal quality in RAID drives using the FC-AL link configuration. The low jitter
transfer peaking and the high jitter tolerance specification of AMCC's clock and data
recovery PLL are essential, allowing more repeaters to be utilized in RAID drives to
ensure signal quality in these applications. In addition, the Lock-Detect circuit monitors
the incoming signals for valid run length, transition density and frequency.
FC-AL RAID subsystems are commonly implemented using a simple JBOD
architecture in which the host adapter provides RAID functionality. AMCC's S2057
and S2058 support this type of design, in which the JBOD acts as an intelligent
FC-AL router to ensure high speed data transfer and hot swapability of disk drives.
Unlike traditional RAID controllers, the JBOD does not have a controller with
separate CPU and memory, but uses the advanced features of the FC-AL disk drives
to provide high-end RAID performance at a fraction of the cost and complexity of
traditional solutions.
The new S2057 and S2058 PBC's are fabricated in AMCC's established, low-power
bipolar process, and are designed to maintain the signal quality of the Fibre Channel
signal passing through unused ports according to the requirements of the Fibre Channel
X3T11 specifications.
The S2057 is packaged in a 20-pin TSSOP that measures 7.2mm (0.283 in.) by
7.8mm (0.31 in.). It uses a 3.3V power supply and dissipates only 0.2 watts. The
S2058 is packaged in a 28-pin SOIC that measures 17.9mm (0.704 in.) by 10.3mm
(0.406 in.). It uses a 3.3V power supply and dissipates only 0.5 watts.
Samples of the S2057 Port Bypass Circuit transceiver are available now, and samples
of the S2058 Port Bypass with Repeater Circuit will be available in November.
Production release of both devices is scheduled for first quarter, 1998. The S2057 is
priced at $9, and the S2058 is priced at $13.20 in quantities of 1,000.
AMCC develops, manufactures and markets high-speed, high reliability system
interface products for data communications, telecommunications, and PCI-based
computer applications. A leading supplier of bipolar ASICs since 1979, AMCC's
corporate headquarters and wafer fabrication facilities are located in San Diego, Calif.
Sales and consulting engineering offices are located throughout the world. For further
information regarding AMCC and its products, write: Marketing Communication
Department, AMCC, 6290 Sequence Drive, San Diego, Calif. 92121-4358; or call
800/755-AMCC (800/755-2622) or 619/450-9333; or fax 619/450-9885; or e-mail
nwpr@amcc.com; or visit the Web site at amcc.com . |
