WG82574L S LBA8 Intel, WG82574L S LBA8 Datasheet - Page 420

• Manufacturer Part Number: WG82574L S LBA8
• Manufacturer: Intel

Specifications of WG82574L S LBA8

• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: 0C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Compliant

13.0
13.1
13.1.1
13.1.2
13.1.3
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Design Considerations
This section provides general design considerations and recommendations when
selecting components and connecting special pins to the 82574.
PCIe
Port Connection to the 82574
PCIe is a dual simplex point-to-point serial differential low-voltage interconnect with a
signaling bit rate of 2.5 Gb/s per direction. The 82574’s PCIe port consists of an
integral group of transmitters and receivers. The link between the PCIe ports of two
devices is a x1 lane that also consists of a transmitter and a receiver pair. Note that
each signal is 8b/10b encoded with an embedded clock.
The PCIe topology consists of a transmitter (Tx) located on one device connected
through a differential pair connected to the receiver (Rx) on a second device. The
82574 can be located on a motherboard or on an add-in card using a connector
specified by PCIe.
The lane is AC-coupled between its corresponding transmitter and receiver. The AC-
coupling capacitor is located on the board close to transmitter side. Each end of the link
is terminated on the die into nominal 100 differential DC impedance. Board
termination is not required.
For more information on PCIe, refer to the PCI Express* Base Specification, Revision
1.1 and PCI Express* Card Electromechanical Specification, Revision 1.1RD.
For information about the 82574’s PCIe power management capabilities, see
section
PCIe Reference Clock
The 82574 uses a 100 MHz differential reference clock, denoted PECLKp and PECLKn.
This signal is typically generated on the system board and routed to the PCIe port. For
add-in cards, the clock is furnished at the PCIe connector.
The frequency tolerance for the PCIe reference clock is +/- 300 ppm.
Other PCIe Signals
The 82574 also implements other signals required by the PCIe specification. The 82574
signals power management events to the system using the PE_WAKE_N signal, which
operates very similarly to the familiar PCI PME# signal. Finally, there is a PE_RST_N
signal, which serves as the familiar reset function for the 82574.
5.0.
82574 GbE Controller—Design Considerations