I347-AT4 Datasheet, PDF (26/148 Pages) Intel Corporation – Intel® Ethernet Network Connection I347-AT4 Datasheet

I347-AT4—Device Functionality
3.1
I347-AT4 Operation and Major Interfaces
The I347-AT4 supports an MDI interface-to-copper cable interface.
The MDI Interface is always a media interface. (The system interface is also known as
MAC interface. It is typically the connection between the PHY and the MAC or the
system ASIC.) For example:
10/100/1000 Mbps
Ethernet MAC
10/100/1000 Mbps
Ethernet MAC
10/100/1000 Mbps
Ethernet MAC
I347-AT4
10/100/1000 Mbps
Ethernet MAC
SGMII (System Interface)
M
RJ45
a
g
n
e
t
i
RJ45
RJ45
Media Types:
- 10BASE-T
- 100BASE-TX
- 1000BASE-T
c
s
RJ45
Figure 5. SGMII System Interface Example — Quad-Port Mode
Port 0
10/100/1000 Mb/s
Ethernet MAC
I347-AT4
10/100/1000 Mb/s
Ethernet MAC
Port 1
SGMII (System Interface)
M
a
g
RJ45
n
e
Media Types:
t
- 10BASE-T
i
- 100BASE-TX
c
RJ45
- 1000BASE-T
s
Figure 6.
3.2
SGMII System Interface Example — Dual-Port Mode
As can be seen from this example, the SGMII interface acts as a system interface.
The I347-AT4 supports one mode of operation: SGMII (system)-to-copper (Register
20_6.2:0 (001b).
Copper Media Interface
The copper interface consists of the MDIP/N[3:0] pins that connect to the physical
media for 1000BASE-T, 100BASE-TX, and 10BASE-T modes of operation.
The I347-AT4 integrates MDI interface termination resistors. The IEEE 802.3
specification requires that both sides of a link have termination resistors to prevent
reflections. Traditionally, these resistors and additional capacitors are placed on the
board between a PHY device and the magnetics. The resistors have to be very accurate
to meet the strict IEEE return loss requirements. Typically, ± 1% accuracy resistors are
used on the board. These additional components between the PHY and the magnetics
complicate board layout. Integrating the resistors has many advantages including
component cost savings, better ICT yield, board reliability improvements, board area
savings, improved layout, and signal integrity improvements.
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