LAN83C183 Datasheet, PDF (32/113 Pages) SMSC Corporation – FAST ETHERNET PHYSICAL LAYER DEVICE

The AutoNegotiation algorithm in the device meets all requirements specified in IEEE
802.3.
AutoNegotiation is only specified for 100BASE-TX and 10BASE-T operation, and
must be disabled when the device is placed in
100BASE-FX mode.
1.2.11.1 10BASE-T LINK INTEGRITY ALGORITHM (10 MBITS/S)
The device implements the same 10BASE-T link integrity algorithm defined in IEEE
802.3. This algorithm uses normal link pulses (NLPs), which are transmitted during
idle periods, to determine if a device has successfully established a link with a remote
device (called Link Pass state). The transmit link pulse meets the template
requirements defined in IEEE 802.3 and shown in Figure 1.6. Refer to IEEE 802.3
for more details if needed.
Figure 1.6 Link Pulse Output Voltage Template (10 Mbits/s)
3.1 V
0 BT
1.3 BT
585 mV
0.5 V/ns
0.5 BT
0.6 BT
+ 50 mV
− 50 mV
0.25 BT
2.0 BT
300 mV
4.0 BT
+ 50 mV
200 mV
− 50 mV
4.0 BT _{42.0 BT}
− 3.1 V
0.85 BT 2.0 BT
1.2.11.2 100BASE-TX LINK INTEGRITY ALGORITHM (100 MBITS/S)
Because the IEEE 802.3 specification defines 100BASE-TX to have an active idle sig-
nal, there is no need to have separate link pulses such as those defined for 10BASE-
T. The LAN83C183 uses the squelch criteria and descrambler synchronization algo-
rithm 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 more details if
needed.
1.2.11.3 AUTONEGOTIATION ALGORITHM
As stated previously, the AutoNegotiation algorithm is used for two purposes:
• To establish a link to and from a remote device
• To automatically configure the device for either 10 or 100 Mbits/s operation and
either Half- or Full-Duplex operation.
The AutoNegotiation algorithm is the same algorithm defined in IEEE 802.3 Clause
28. AutoNegotiation uses a burst of link pulses, called fast link pulses (FLPs), to pass
up to 16 bits of signaling data back and forth between the LAN83C183 and a remote
device. The transmit FLP pulses meet the template specified in IEEE 802.3 and
SMSC DS – LAN83C183
32
Rev. 12/14/2000