VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7128
Features
• Supports ANSI X3T11 1.0625Gb/s FC-AL Disk
Attach for Resiliency
• Dual Repeaters (CRUs) Improve Signal Quality
• Six Port Bypass Circuits (PBCs) for Resiliency
• Dual Digital Signal Detect Units (SDUs)
Hex Port Bypass Circuit / Dual Repeater
for 1.0625 Gb/s FC-AL Disk Arrays
• Fully Differential for Minimum Jitter
• Selectable REFCLK: 53.125 / 106.25MHz
• TTL Bypass Select
• 3.3V Supply, 1.3W
• 64-Pin, 14 mm Thermally Enhanced PQFP
General Description
The VSC7128 contains six Port Bypass Circuits (PBCs), dual embedded Clock Recovery Unit repeaters
(CRU) and dual Signal Detect Units (SDU). These functions are integrated into a single part to minimize circuit
size, part count, cost, high frequency routing and jitter accumulation. Together, they allow for optimized designs
of FC-AL JBOD systems that provide resiliency and hot insertion/removal of disk drives. The PBCs configure
the FC-AL loop to either include or exclude each drive. Repeaters retime the incoming signal thereby attenu-
ating jitter so that downstream devices see high amplitude, low jitter signals. The SDUs determine whether the
output of the CRU is a valid Fibre Channel signal. Disk drives are connected directly to the LSO/LSI/SEL pins
while the IN/OUT pins can be connected to any FC-AL devices.
VSC7128 Block Diagram
DISK
DRIVE
#1
DISK
DRIVE
#2
DISK
DRIVE
#3
DISK
DRIVE
#4
DISK
DRIVE
#5
DISK
DRIVE
#6
LSO1+
LSO1-
LSI1+
LSI1-
SEL1
LSO2+
LSO2-
LSI2+
LSI2-
SEL2
LSO3+
LSO3-
LSI3+
LSI3-
SEL3
LSO4+
LSO4-
LSI4+
LSI4-
SEL4
LSO5+
LSO5-
LSI5+
LSI5-
SEL5
SDU1
FAIL1-
Previous Device
IN1+
IN1-
CRU1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
OUT2+
OUT2-
PBC1
OUT1+
OUT1-
PBC2
PBC3
PBC4
PBC5
MUX7
0
1
PBC6
IN2+
IN2-
CRU2
SDU2
FAILSEL
RFSEL
REFCLK
(106/53 MHz)
CMU
FAIL2-
SEL8
SEL7
G52177-0, Rev. 2.3
8/31/98
©
VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Next Device
Page 1
MUX8
LSO6+
LSO6-
LSI6+
LSI6-
SEL6
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
