KSZ8842MQL Datasheet, PDF (30/141 Pages) Micrel Semiconductor – 2-Port Ethernet Switch with Non-PCI Interface

Micrel, Inc.
KSZ8842-16/32 MQL/MVL/MVLI/MBL
Crossover Cable
A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device. The
following diagram shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).
Figure 8. Typical Crossover Cable Connection
Auto Negotiation
The KSZ8842M conforms to the auto negotiation protocol as described by the 802.3 committee to allow the channel to
operate at 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 KSZ8842M 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 9).
October 2007
30
M9999-102207-1.9