RTL8111 Ver la hoja de datos (PDF) - Realtek Semiconductor

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RTL8111

INTEGRATED GIGABIT ETHERNET CONTROLLER FOR PCI EXPRESS™ APPLICATIONS

Realtek Semiconductor 

RTL8111

Datasheet

6. Functional Description

6.1. PCI Express Bus Interface

The RTL8111 is compliant with PCI Express Base Specification Revision 1.0a, and runs at a 2.5GHz

signaling rate with X1 link width, i.e., one transmit and one receive differential pair. The RTL8111

supports four types of PCI Express messages: interrupt messages, error messages, power management

messages, and hot-plug messages. The PCI Express lane polarity reversal and link reversal are also

supported to ease PCB layout constraints.

6.1.1. PCI Express Transmitter

The RTL8111’s PCI Express block receives digital data from the Ethernet interface and performs data

scrambling with Linear Feedback Shift Register (LFSR) and 8B/10B coding technology into 10-bit code

groups. Data scrambling is used to reduce the possibility of electrical resonance on the link, and 8B/10B

coding technology is used to benefit embedded clocking, error detection, and DC balance by sacrificing a

25 percent overhead to the system through the addition of 2 extra bits. The data code groups are passed

through its serializer for packet framing. The generated 2.5Gbps serial data is transmitted onto the PCB

trace to its upstream device via a differential driver.

6.1.2. PCI Express Receiver

The RTL8111’s PCI Express block receives 2.5Gbps serial data from its upstream device to generate

parallel data. The receiver’s PLL circuits are resynchronized to maintain bit and symbol lock. Through

8B/10B decoding technology and data descrambling, the original digital data is recovered and passed to

the RTL8111’s internal Ethernet MAC to be transmitted onto the Ethernet media.

6.2. LED Functions

The RTL8111 supports 4 LED signals in 4 different configurable operation modes. The following sections

describe the various LED actions.

6.2.1. Link Monitor

The Link Monitor senses link integrity, such as LINK10, LINK100, LINK1000, LINK10/100/1000,

LINK10/ACT, LINK100/ACT, or LINK1000/ACT. Whenever link status is established, the specific link

LED pin is driven low. Once a cable is disconnected, the link LED pin is driven high, indicating that no

network connection exists.

Integrated Gigabit Ethernet Controller for PCI Express 7

Track ID: JATR-1076-21 Rev. 1.2

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