Phytec phyCORE-i.MX31, Hardware Manual

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phyCOREi.MX31
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PHYTEC Messtechnik GmbH 2007 L-700e_0
9 Ethernet Controller (U3)
Connection of the phyCORE-i.MX31 to the world wide web (WWW) or a local area
network (LAN) is possible with the on-board SMSC LAN9215/17 10/100 Mbps Ethernet
controller populating the module at U3. This Ethernet controller features an integrated
PHY layer, thus reducing the external components required to connect the phyCORE-
i.MX31 to a LAN; external components are limited to the transformer, the RJ45 socket
and a few discrete components. Support for this Ethernet chip is available from a wide
range of operating systems, such as Linux and WinCE.
In addition to the integrated PHY layer, the SMSC LAN9215/17 also supports HP Auto-
MDIX technology, eliminating the need for the consideration of a direct connect LAN
cable, or a cross-over patch cable. The LAN9215/17 detects the TX and RX pins of the
connected device and automatically configures the PHY TX and RX pins accordingly.
The Ethernet controller is connected to the address/data bus with a 16-bit width and
x_GPIO3_1 as interrupt. The interrupt is being used as active low, edge triggered. The
/CS signal is connected to the i.MX31 processor's x_/CS1 signal. The Ethernet
controller's offset of 0x300 has to be noted when accessing the chip.
The Ethernet controller provides a PME output that can be externally connected to a
GPIO input of the controller for signalling a system wake-up event.
The physical memory area for the Ethernet chip is defined in Table 12. An offset of 0x300
has to be added to the address of x_/CS1.
Table 12: Ethernet controller memory map
E
THERNET
S
TART
A
DDRESS
x_/CS1 + OFFSET 0xA800 00000 + 0x0000 0300 = 0xA800 0300
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 design specifications provided by SMSC when creating the Ethernet
transformer circuitry.