Preliminary
VN16118
SERDES
Gigabit Ethernet Transceiver
Applications
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Gigabit Ethernet Up-links
High Speed Proprietary
interface
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Backplane Serialization
Bus Extender
General Description
The VN16118 is a single chip,1.25 Gigabits per second Ethernet transceiver. It performs all the
functions of the Physical Medium Attachment (PMA) portion of the Physical layer, as specified
by the IEEE 802.3z Gigabit Ethernet standard. These functions include parallel-to-serial and
serial-to-parallel conversion, clock generation, clock data recovery, and word synchronization.
In addition, an internal loopback function is provided for system debugging.
The VN16118 is ideal for Gigabit Ethernet, serial backplane and proprietary point-to-point
applications. The device supports both 1000BASE-LX and 1000BASE-SX fiber-optic media,
and 1000BASE-CX copper media.
The transmitter section of the VN16118 accepts 10-bit wide parallel TTL data and converts it to
a high speed serial data stream. The parallel data is encoded in 8b/10b format. This
incoming parallel data is latched into an input register, and synchronized on the rising edge of
the 125 MHz reference clock supplied by the user. A phase locked loop (PLL) locks to the 125
MHz clock. The clock is then multiplied by 10 to produce a 1.25 GHz serial clock that is used
to provide the high speed serial data output. The output is sent through a Pseudo Emitter
Coupled Logic (PECL) driver. This output connects directly to a copper cable in the case of
1000BASE-CX medium, or to a fiber optic module in the case of 1000BASE-LX or 1000BASE
SX fiber optic medium.
The receiver section of the VN16118 accepts a serial PECL-compatible data stream at a 1.25
Gbps rate, recovers the original 10-bit wide parallel data format, and retimes the data. A Phase
Lock Loop (PLL) locks on to the incoming serial data stream, and recovers the 1.25 GHz high
speed serial clock and data. This is accomplished by continually frequency locking on to the
125 MHz reference clock, and by phase locking on to the incoming data stream. The serial
data is converted back to parallel data format. The ‘comma’ character is used to establish byte
alignment. Two 62.5 MHz clocks, 180 degrees out of phase, are recovered. These clocks are
alternately used to clock out the parallel data on the rising edge. This parallel data is sent to
the user in TTL-compatible form.
Features
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•
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IEEE 802.3z Gigabit Ethernet
Compliant
Supports 1.25 Gbps Using NRZ Coding
over uncompensated twin-coax cable
Fully integrated CMOS IC
Low Power Consumption
ESD rating >2000V (Human Body
Model) or >200V (Machine Model)
•
•
•
5-Volt Input Tolerance
Fully Compatible with HP HDMP-
1636/HDMP-1646 and Vitesse
VCS7135 transceivers
Available in both 10 mm x 10 mm
and 14 mm x 14 mm LQFP
Packages
1999-12-15
Page 1
MDSN-0001-00
Vaishali Semiconductor
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747 Camden Avenue
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Campbell
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CA 95008
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Ph. 408.379.2900
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Fax 408.379.2937
VAISH [ VAISHALI SEMICONDUCTOR ]
