Fast Ethernet 10/100 Quad Transceivers — LXT974/LXT975
Contents
1.0
2.0
Pin Assignments and Signal Descriptions....................................................10
Functional Description...........................................................................................19
2.1
2.2
Introduction..........................................................................................................19
Network Media / Protocol Support.......................................................................20
2.2.1 10/100 Mbps Network Interface .............................................................20
2.2.1.1 Twisted-Pair Interface ...............................................................20
2.2.1.2 Fiber Interface ...........................................................................21
2.2.2 MII Interface ...........................................................................................21
2.2.2.1 MII Data Interface......................................................................21
2.2.2.2 MII Management Interface ........................................................24
2.2.3 Hardware Control Interface ....................................................................25
Initialization..........................................................................................................27
2.3.1 MDIO Control Mode ...............................................................................27
2.3.2 Manual Control Mode.............................................................................27
2.3.3 Link Configuration ..................................................................................28
Auto-Negotiation..................................................................................................29
2.4.1 Parallel Detection ...................................................................................29
2.4.2 Controlling Auto-Negotiation ..................................................................29
2.4.3 Monitoring Auto-Negotiation...................................................................29
100 Mbps Operation............................................................................................30
2.5.1 100BASE-X MII Operations....................................................................30
2.5.2 100BASE-X Network Operations ...........................................................30
2.5.3 100BASE-X Protocol Sublayer Operations ............................................33
2.5.4 PCS Sublayer.........................................................................................33
2.5.4.1 Preamble Handling....................................................................33
2.5.4.2 Data Errors................................................................................34
2.5.4.3 Collision Indication ....................................................................34
2.5.5 PMA Sublayer ........................................................................................35
2.5.5.1 Link............................................................................................35
2.5.5.2 Link Failure Override.................................................................35
2.5.5.3 Carrier Sense (CRS) .................................................................35
2.5.6 Twisted-Pair PMD Sublayer ...................................................................35
2.5.6.1 Scrambler/Descrambler (100TX Only) ......................................35
2.5.6.2 Baseline Wander Correction .....................................................36
2.5.6.3 Polarity Correction.....................................................................36
2.5.7 Fiber PMD Sublayer...............................................................................36
10 Mbps Operation..............................................................................................36
2.6.1 10BASE-T MII Operation........................................................................36
2.6.2 10BASE-T Network Operations..............................................................36
2.6.2.1 Preamble Handling....................................................................37
2.6.2.2 Link Test....................................................................................37
2.6.2.3 Link Failure................................................................................37
2.6.2.4 SQE (Heartbeat)........................................................................37
2.6.2.5 Jabber .......................................................................................37
LED Functions.....................................................................................................37
2.7.1 Serial LED Output ..................................................................................38
2.3
2.4
2.5
2.6
2.7
Datasheet
3