LAN8710A Datasheet, PDF (43/82 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
Collision Test is enabled in the Basic Control Register. The transmitters are powered down regardless
of the state of TXEN.
10/100
Ethernet
MAC
TXD
RXD
Digital
X ^TX
X ^RX
Analog
SMSC
Ethernet Transceiver
XFMR
CAT-5
3.8.9.2
Figure 3.9 Near-end Loopback Block Diagram
Far Loopback
Far loopback is a special test mode for MDI (analog) loopback as indicated by the blue arrows in
Figure 3.11. The far loopback mode is enabled by setting the FARLOOPBACK bit of the Mode
Control/Status Register to “1”. In this mode, data that is received from the link partner on the MDI is
looped back out to the link partner. The digital interface signals on the local MAC interface are isolated.
Note: This special test mode is only available when operating in RMII mode.
Far-end system
10/100
Ethernet
MAC
TXD _X
RXD _X
Digital
Analog
SMSC
Ethernet Transceiver
TX
XFMR
RX
CAT-5
Link
Partner
3.8.9.3
Figure 3.10 Far Loopback Block Diagram
Connector Loopback
The device maintains reliable transmission over very short cables, and can be tested in a connector
loopback as shown in Figure 3.11. An RJ45 loopback cable can be used to route the transmit signals
SMSC LAN8710A/LAN8710Ai
43
DATASHEET
Revision 1.4 (08-23-12)