DM9161AEP Product Brief
10/100 Mbps Fast Ethernet Physical Layer Single Chip Transceiver
June 2008 Rev.1.0
The DM9161A is a physical layer, single-chip, and low power transceiver for
100BASE-TX and 10BASE-T operations. On the media side, it provides a direct
interface either to Unshielded Twisted Pair Category 5 Cable (UTP5) for
100BASE-TX Fast Ethernet, or UTP5/UTP3 Cable for 10BASE-T Ethernet. Through
the Media Independent Interface (MII), the DM9161A connects to the Medium
Access Control (MAC) layer, ensuring a high inter operability from different vendors.
TheDM9161A uses a low power and high performance advanced CMOS process. It
contains the entire physical layer functions of 100BASE-TX as defined by
IEEE802.3u, including the Physical Coding Sublayer (PCS), Physical Medium
Attachment (PMA), Twisted Pair Physical Medium Dependent Sublayer (TP-PMD),
10BASE-TX Encoder/Decoder (ENC/DEC), and Twisted Pair Media Access Unit
(TPMAU). The DM9161A provides a strong support for the auto-negotiation function,
utilizing automatic media speed and protocol selection. Furthermore, due to the
built-in wave shaping filter, the DM9161A needs no external filter to transport signals
to the media in 100BASE-TXBASE-TX or 10BASE-TBASE-T Ethernet operation.
Block Diagram
25M OSCI
LED1-4#
TX CGM
LED
Driver
4B/5B
Encoder
Scrambler
Parallel
to Serial
NRZ
to
NRZI
NRZI to
MLT-3
MLT-3
Driver
100TXD+/-
Rise/Fall
Time
CTL
25M CLK
125M CLK
MII
Signals
MII
Interface/
Control
AutoMDIX
4B/5B
Decoder
Code-
group
Alignment
Descrambler
Serial to
Parallel
NRZI
to
NRZ
RX
CRM
MLT-3 to
NRZI
Adaptive
EQ
RXI+/-
Digital
Logic
10BASE-T
Module
RX
TX
RXI+/-
10TXD+/-
Register
Collision
Detection
Carrier
Sense
Auto-
Negotiation
DAVICOM [ DAVICOM SEMICONDUCTOR, INC. ]
