DM9301 View Datasheet(PDF) - Davicom Semiconductor, Inc.
Part Name
Description
Manufacturer
DM9301 Datasheet PDF : 22 Pages
| |||
DM9301
100Mbps Ethernet Fiber/Twisted Pair Single Chip Media Converter
Functional Description
The DM9301 Fast Ethernet single-chip TX/FX media
converter, provides the functionality as specified in
IEEE802.3, integrates the complete 100BASE-TX and a
PECL optic module interface for 100Base-FX. The
DM9301 implements the PCS, PMA, and TP-PMD
sublayer functions, as defined by specification. The term
“X” will be used to describe the sections used in the fiber
PHY layer interface. The term “X” will be used to describe
the sections used in the twisted-pair PMD layer interface.
100BASE-FX to TX Operation
The block diagram in figure 1 provides an overview of the
functional blocks contained in the FX to TX media
converter interface.
The FX to TX interface includes the following functional
blocks:
• FX PECL Receiver
• FX Receiver Clock Recovery Module
• FX NRZI to NRZ Converter
• FX Serial to Parallel Converter
• FX Code Group Alignment Monitor
• TX Scrambler
• TX Parallel to Serial Converter
• TX NRZ to NRZI Converter
• TX NRZI to MLT-3 Converter
• TX MLT-3 Driver
FX PECL Receiver
The PECL receiver receives NRZI encoded, differential
Pseudo Emitter Coupled Logic level signal. The receiver
converts the receive signal into a single-ended NRZI
signal and presents this signal to the FX Clock Recovery
Module.
FX Receiver Clock Recovery Module
The FX Clock Recovery Module accepts NRZI data from
the PECL receiver. The FX Clock Recovery Module locks
onto the data stream, using a Phase Lock Loop (PLL) and
extracts the 125Mhz reference clock. The extracted and
synchronized clock and data are presented to the FX
NRZI to NRZ Decoder.
FX NRZI to NRZ Converter
The receive data stream is required to be NRZI encoded
for compatibility with the standards for 100Base- FX. This
conversion process must be reversed on the transmit end.
The FX NRZI to NRZ decoder, receives the NRZI
data stream from the FX Clock Recovery Module
and converts it to a NRZ data stream to be
presented to the FX Serial to Parallel conversion
block.
PECLSD
FXSD
RCVR
PECLRXI +/-
FX
PECL
RCVR
25M
OSC/XTAL
FX
RX
CRM
CGM
25M FXRXCLK
125M FXRXCLK
FX Link
Status
Monitor
FX
NRZI
to
NRZ
FX Serial
to
Parallel
TX
Scrambler
FX Code-
group
Alignment
Monitor
TX
Parallel
to Serial
TX
NRZ
to
NRZI
TX
NRZI to
MLT-3
Rise/Fall
Time
CTL
MLT-3
Driver
TPTXO+/-
FX to TX Block Diagram
Figure 1
10
Final
Version: DM9301-DS-F02
May 8, 2000
Share Link: 