ksz8851-mql Micrel Semiconductor, ksz8851-mql Datasheet - Page 27

• Manufacturer Part Number: ksz8851-mql
• Description: Single-port Ethernet Mac Controller With 8/16-bit Or 32-bit Non-pci Interface
• Manufacturer: Micrel Semiconductor

Auto Negotiation
The KSZ8851M conforms to the auto negotiation protocol as described by the 802.3 committee to allow the port to
operate at either 10Base-T or 100Base-TX.
Auto negotiation allows unshielded twisted pair (UTP) link partners to select the best common mode of operation. In auto
negotiation, the link partners advertise capabilities across the link to each other. If auto negotiation is not supported or the
link partner to the KSZ8851M is forced to bypass auto negotiation, the mode is set by observing the signal at the receiver.
This is known as parallel mode because while the transmitter is sending auto negotiation advertisements, the receiver is
listening for advertisements or a fixed signal protocol.
The link setup is shown in the following flow diagram (Figure 6).
February 2009
Micrel, Inc.
Media Dependent Interface
Modular Connector (RJ-45)
Transmit Pair
Receive Pair
(Repeater or Switch)
10/100 Ethernet
Figure 5. Typical Crossover Cable Connection
HUB
1
2
3
4
5
6
7
8
Crossover
Cable
27
Media Dependent Interface
Modular Connector (RJ-45)
(Repeater or Switch)
1
2
3
4
5
6
7
8
10/100 Ethernet
Transmit Pair
HUB
Receive Pair
KSZ8851-16/32 MQL/MQLI
M9999-021309-1.1