8101 datasheet(44/172 Pages) LSI

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2-26

Functional Description

• Adds the end of packet delimiter

• Adds the idle code stream

• Formats the packet according to the 10B PHY format deﬁned in IEEE

802.3z and shown in Figure 2.3

The 8B10B encoded data stream is then sent to the transmit 10-bit PHY

interface for transmission.

The transmit 8B10B PCS section also generates the AutoNegotiation

code stream when the controller is in the AutoNegotiation process.

The receive 8B10B PCS section takes the 8B10B encoded packet data

from the incoming 10-bit PHY interface and:

• Acquires and maintains word synchronization

• Strips off the start of packet delimiter

• Strips off the end of packet delimiter

• Strips off the idle code stream

• Decodes the data with the 8B10B decoder

• Converts the packet to the Ethernet packet format shown in

Figure 2.2

The Ethernet packet is then sent to the receive MAC for processing.

The receive 8B10B PCS section also decodes the AutoNegotiation code

stream when the controller is in the AutoNegotiation process.

2.11.1 8B10B Encoder

The 8B10B encoder converts each data byte of a packet into a unique

10-bit word as deﬁned in IEEE 802.3z and shown in Table 2.7 (in

abbreviated form).

8101 Datasheet(PDF) 44 Page - LSI Computer Systems