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Rev 1.0 04/17/2006
Released
Literature # ADS-005104
2.14.2
10/100 Ethernet
Transceiver –
Manufacturer: National Semiconductor
Part #:
DP83847ALQA56A
Connector –
Manufacturer: Pulse
Part #:
J0026D01B
The on-board Ethernet PHY is a National DP83847ALQA56A DsPHYTER® II. The DP83847 is a small, low power physical layer
transceiver that only requires a single 3.3V supply. The PHY supports 3.3V signaling levels to the MAC interface, in this case the
Spartan-3 FPGA. The PHY is connected to a Pulse RJ-45 jack with integrated magnetics (part number: J0026D01B). The jack also
integrates two LEDs to show Link and Receive Activity. Four more LEDs are provided on the board for status indication. These LEDs
indicate Link Speed (D13), Transmit Activity (D11), Collision Detect (D10) and Full Duplex operation (D12). The PHY clock is
generated from its own 25 MHz crystal. The PHY address is set to binary “00011”. Three-pad resistor jumpers were used to set the
operating mode (JT1, JT2 and JT3). An illustration of the resistor jumper footprint is shown below.
Figure 17 - Resistor Jumper Pin-out
These jumper pads provide the user with the ability to change the operating mode by moving the resistors. By default the PHY is set to
auto negotiate a link with a peer. The available modes of operation are shown in the table below.
Operating Modes
JT3
JT2
JT1
10BaseT Half Duplex, Forced Mode
2-3
2-3
2-3
10BaseT Full Duplex, Forced Mode
2-3
2-3
1-2
100Base-TX Half Duplex, Forced Mode
2-3
1-2
2-3
100Base-TX Full Duplex, Forced Mode
2-3
1-2
1-2
10BaseT Half/Full Duplex Advertised, Auto-negotiate
1-2
2-3
2-3
100Base-TX Half/Full Duplex Advertised, Auto-negotiate
1-2
2-3
1-2
10BaseT/100Base-TX Half Duplex Advertised, Auto-negotiate
1-2
1-2
2-3
10BaseT/100Base-TX Half/Full Duplex, Auto-negotiate (Default)
1-2
1-2
1-2
Table 22 - Ethernet PHY Modes
Reference Designator
Function
Note
JP8
Ethernet Enable
Installed by default
JT1-3
Operating Mode
Resistor Jumpers
(see table above)
D10 Collision
Detect
D11 TX
Activity
D12 Duplex
D13 Speed
Indicator
Table 23 - Ethernet Jumpers and LEDs
The use of this port requires an Ethernet MAC core to be instantiated in the FPGA project. The example project that includes network
support utilizes a licensed IP core from Xilinx. A valid license for this IP may be required to regenerate the project. The following table
provides the FPGA pin numbers for the Ethernet PHY interface.
JP8
RJ45
10/100 Eth
Eth En
D13 D11 D10 D12
Speed
TX Col Dup
RJ45 Ethernet Connector
“Link”
“RX Active”