LAN8710A Datasheet, PDF (28/82 Pages) SMSC Corporation – Small Footprint MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR Technology

Small Footprint MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR^® Technology
Datasheet
3.2.3
3.2.4
signal transmitted by the link partner. Auto-negotiation resumes in an attempt to determine the new
link configuration.
If the management entity re-starts auto-negotiation by setting the Restart Auto-Negotiate bit of the
Basic Control Register, the LAN8710A/LAN8710Ai will respond by stopping all transmission/receiving
operations. Once the break_link_timer is completed in the Auto-negotiation state-machine
(approximately 1200ms), auto-negotiation will re-start. In this case, the link partner will have also
dropped the link due to lack of a received signal, so it too will resume auto-negotiation.
Disabling Auto-negotiation
Auto-negotiation can be disabled by setting the Auto-Negotiation Enable bit of the Basic Control
Register to zero. The device will then force its speed of operation to reflect the information in the Basic
Control Register (Speed Select bit and Duplex Mode bit). These bits should be ignored when auto-
negotiation is enabled.
Half vs. Full Duplex
Half duplex operation relies on the CSMA/CD (Carrier Sense Multiple Access / Collision Detect)
protocol to handle network traffic and collisions. In this mode, the carrier sense signal, CRS, responds
to both transmit and receive activity. If data is received while the transceiver is transmitting, a collision
results.
In full duplex mode, the transceiver is able to transmit and receive data simultaneously. In this mode,
CRS responds only to receive activity. The CSMA/CD protocol does not apply and collision detection
is disabled.
Revision 1.4 (08-23-12)
28
DATASHEET
SMSC LAN8710A/LAN8710Ai