phyCORE-OMAP44xx
Part I: PCM-049/phyCORE-OMAP44xx System on Module
L-760e_1 © PHYTEC Messtechnik GmbH 2012
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connected device and automatically configures the PHY TX and RX pins accordingly. The Ethernet controller also
provides wake on LAN and other power management modes. To integrate the power management features of
the Ethernet controller into the application's power management concept the power management event signal
(PME) of the LAN9221 is available at pin X1C44 of the phyCORE-Connector (please refer to the SMSC LAN9221
datasheet for further information on this signal). Utilization of this signal allows to wake-up the application by
a power management circuitry on the custom target hardware. The PEM signal is also connected to the
Peripheral 2A Power Request input (PREQ2A) of the PMIC TWL6030. Consequently it is also possible to interpret
the signal on the phyCORE-OMAP44xx without the need to design an external power management circuitry
1
.
If pin X1C44 of the phyCORE-OMAP44xx, or the Peripheral 2A Power Request input (PREQ2A) of the PMIC
TWL6030 are intend for a different function de-soldering of resistor R69 and mounting of resistor R70 discon-
nects the PME signal from the phyCORE-Connector and PREQ2A and connects it to the Peripheral 2B Power
Request input (PREQ2B) of the PMIC TWL6030 instead.
The Ethernet controller is connected to chip select CS5 of the General-Purpose Memory Controller (GPMC).
The start address for CS5 is configurable (e.g. for the Phytec Linux BSP the start address is set to 0x2C00 0000).
Please refer to the OMAP44xx Reference Manual for more information on how to configure the address space for
CS5 etc.
Connecting the phyCORE-OMAP44xx to an existing 10/100Base-T network involves adding an RJ45 and
appropriate magnetic devices in your design. The required 49,9 Ohm +/-1% termination resistors on the analog
signals (ETH_RX±, ETH_TX±) are already populated on the module. Connection to an external Ethernet
magnetics 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.
If a power management is implemented which allows to turn off the Ethernet controller's supply voltage
VCC_3V3_S special care must be taken to avoid a reverse current over the terminating resistors. In this case the
reference voltage VCC_3V3_S which is available at pin X1D23 of the phyCORE-Connector should be used to
switch off any supply voltage attached to the center tap of the magnetics located on the target hardware.
Please consult the phyCORE-OMAP44xx Carrier Board schematics as a reference.
If you are using the applicable carrier board for the phyCORE-OMAP44xx (part number PCM-959), the external
circuitry mentioned above is already integrated on the board (refer to
).
1.8.5.2 MAC Address EEPROM (U13)
In a computer network such as a local area network (LAN), the MAC (Media Access Control) address is a unique
computer hardware number. For a connection to the Internet, a table is used to convert the assigned IP number
to the hardware's MAC address.
In order to guarantee that the MAC address is unique, all addresses are managed in a central location.
PHYTEC has acquired a pool of MAC addresses. The MAC address of the phyCORE-OMAP44xx is located on the bar
code sticker attached to the module. This number is a 12-digit HEX value.
An EEPROM at U13 is used to store the MAC address.
1.
All special functions of the PMIC such as use of PREQ2A, etc. require the PMIC to be programmed via I
2
C interface. At the time of
delivery only the generation of the required voltages is implemented . Please refer to the TWL6030 Technical Ref. Man. for more
information on how to program the PMIC.
Caution:
Please see the datasheet of the Ethernet controller when designing the Ethernet transformer circuitry.
