RTD Embedded Technologies, Inc.
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17
LAN17222 User’s Manual
5
Functional Description
Block Diagram
The Figure below shows the functional block diagram of the LAN17222. The various parts of the block diagram are discussed in the following
sections.
Figure 8: LAN17222 Block Diagram
PCI to PCIe Bridge
The PCI to PCI-Express Bridge allows this Legacy PCI device to take advantage of PCI Express interfacing chips. It utilizes a single 33 MHz,
32-Bit PCI lane to create an x1 PCI Express link. This link is replicated and sent to the two Gigabit Ethernet controllers on the board.to PCI
Bridge allows legacy PCI devices to be used with newer PCI Express chipsets.
5.2.1
PCI
E
XPRESS
H
UB
The LAN17222 has an onboard PCI Express Signal Hub which allows it to provide a PCI Express link to each of the Ethernet controllers.
Intel WG82574IT Gigabit Ethernet Controller
The LAN17222 features two Gigabit Ethernet ports controlled by Intel’s WG82574IT Gigabit Ethernet controller. The WG82574IT is an
industrial temperature rated Gigabit Ethernet controller which features Auto-Crossover for MDI/MDI-X, 9KB Jumbo Frame Support, 40KB
packet buffer size and IPv4/6 support.
Link/Activity/Speed LEDs
Each Ethernet port has LED indicators which show link, activity and the speed of the connection.
Yellow LED: On indicates the link has been established. Blinks with activity
Blue LED: On indicates connection at 100 Mbps speed.
Green LED: On indicates connection at 1 Gbps speed.
PCI to
PCIe
Bridge
82574
Gig-E
Controller
PC
I B
us
PCI Link
PCI-Express
Hub
82574
Gig-E
Controller
0.1” DIL
or
RJ45
0.1” DIL
or
RJ45
x1 PCI-E Link
