Phytec phyCORE-i.MX27, Hardware Manual

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phyCOREi.MX27
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PHYTEC Messtechnik GmbH 2011 L-710e_5
10 Ethernet Controller / Ethernet-Phy (U9)
Connection of the phyCORE-i.MX27 to the world wide web (WWW) or a local area network (LAN) is
possible with the internal 10/100 Mbps Fast Ethernet controller. With this Ethernet controller an
external transceiver interface and transceiver function are required to complete the interface to the
media. Therefor the i.MX27 uses an Ethernet-Phy (U9).
The Ethernet-Phy provides MII/RMII/SMII interfaces to transmit and receive data. In addition the PHY
also supports HP Auto-MDIX technology, eliminating the need for the consideration of a direct
connect LAN cable, or a cross-over patch cable. It detects the TX and RX pins of the connected
device and automatically configures the PHY TX and RX pins accordingly. The Ethernet-Phy also
features LinkMD cable diagnostics, which allows detection of common cabling plant problems such as
open and short circuits.
The physical memory area for the Fast Ethernet controller is defined in
Table 15.
Table 15: Fast Ethernet controller memory map
A
DDRESS
F
UNCTION
0x 0x000-1FF Control/Status Registers
0x 0x200-3FF MIB Block Counters
Connection to an external Ethernet transformer should be done using very short signal traces. The
TPI+/TPI- and TPO+/TPO- signals should be routed as 100 Ohm differential pairs. The same applies
for the signal lines after the transformer circuit. The carrier board layout should avoid any other signal
lines crossing the Ethernet signals.
Caution!
Please note the datasheet of the Ethernet-Phy when creating the Ethernet transformer circuitry.