LAN91C111 Datasheet, PDF (33/125 Pages) SMSC Corporation – 10/100 Non-PCI Ethernet Single Chip MAC + PHY

LAN91C111
FIGURE 7-7:
LINK PULSE OUTPUT VOLTAGE TEMPLATE - NLP, FLP
0
1.3
BT
BT
3.1 V
0.5 V/ns
585 mV
0.5
BT _0.6
BT
2.0
BT
4.0
300 mV
BT
+50 mV
-50 mV
0.25
BT
200 mV
4.0
42.0
BT
BT
+50 mV
-50 mV
-3.1 V
0.85
2.0
BT
BT
7.7.12.3 100BASE-TX Link Integrity Algorithm - 100Mbps
Since 100BASE-TX is defined to have an active idle signal, then there is no need to have separate link pulses like those
defined for 10BASE-T. The LAN91C111 uses the squelch criteria and descrambler synchronization algorithm on the
input data to determine if the device has successfully established a link with a remote device (called Link Pass State).
Refer to IEEE 802.3 for both of these algorithms for more details.
7.7.12.4 Auto-Negotiation Algorithm
As stated previously, the Auto-Negotiation algorithm is used for two purposes: (1) To automatically configure the device
for either 10/100 Mbps and Half/ Full Duplex modes, and (2) to establish an active link to and from a remote device. The
Auto-Negotiation algorithm is the same algorithm that is defined in IEEE 802.3 Clause 28. Auto-Negotiation uses a burst
of link pulses, called fast link pulses and referred to as FLP'S, to pass up to 16 bits of signaling data back and forth
between the LAN91C111 and a remote device. The transmit FLP pulses meet the templated specified in IEEE 802.3
and shown in Figure 7-7. A timing diagram contrasting NLP's and FLP's is shown in Figure 7-8.
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DS00002276A-page 33