參數(shù)資料
型號: L80227
廠商: LSI CORP
元件分類: 網(wǎng)絡(luò)接口
英文描述: 10BASE-T/100BASE-TX Ethernet Physical Layer Device (PHY)(10BASE-T/100BASE-TX 以太網(wǎng)物理層處理器)
中文描述: DATACOM, ETHERNET TRANSCEIVER, PQFP64
封裝: LQFP-64
文件頁數(shù): 35/158頁
文件大?。?/td> 1084K
代理商: L80227
Draft 6/5/00
Block Diagram Description
2-15
Copyright 1999 by LSI Logic Corporation. All rights reserved.
2.3.4 Decoder
This section describes the 4B5B decoder, used in 100 Mbits/s operation,
which converts 5B encoded data to 4B nibbles. It also describes the
Manchester Decoder, used in 10BASE-T operation.
2.3.4.1 4B5B Decoder (100 Mbits/s)
Because the TP input data is 4B5B encoded on the transmit side, the
4B5B decoder must decode it on the receive side. The mapping of the
5B codewords to the 4B nibbles is specified in IEEE 802.3. The 4B5B
decoder takes the 5B codewords from the descrambler, converts them
into 4B nibbles according to
Table 2.5
, and sends the 4B nibbles to the
receive Ethernet controller.
The 4B5B decoder also strips off the SSD delimiter (/J/K/ symbols), and
replaces it with two 4B Data 5 nibbles (/5/ symbol). It also strips off the
ESD delimiter (/T/R/ symbols), and replaces it with two 4B Data 0 nibbles
(/I/ symbol), per IEEE 802.3 specifications (see
Figure 2.2
).
The 4B5B decoder detects SSD, ESD, and codeword errors in the
incoming data stream as specified in IEEE 802.3. To indicate these
errors, the device asserts the RX_ER output while the errors are being
transmitted across RXD[3:0].
2.3.4.2 Manchester Decoder (10 Mbits/s)
In Manchester coded data, the first half of the data bit contains the
complement of the data, and the second half of the data bit contains the
true data. The Manchester Decoder converts the single data stream from
the TP receiver into non-return to zero (NRZ) data for the controller
interface. To do this, it decodes the data and strips off the SOI pulse.
Because the Clock and Data Recovery block has already separated the
clock and data from the TP receiver, that block inherently performs the
the Manchester decoding.
相關(guān)PDF資料
PDF描述
L8050HPLT1 General Purpose Transistors NPN Silicon
L8050HPLT1G General Purpose Transistors NPN Silicon
L8050HQLT1 General Purpose Transistors NPN Silicon
L8050HQLT1G General Purpose Transistors NPN Silicon
L8050LT1 General Purpose Transistors NPN Silicon
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L80227/B 制造商:LSI Corporation 功能描述: 制造商:LSI Corporation 功能描述:L80227/B
L80227/BI 制造商:LSI Corporation 功能描述:L80227/BI
L80227FR 制造商:LAUREL ELECTRONICS 功能描述:Laureate 1/8 DIN multi-function counter / timer, universal 85-264 Vac power, two
L80227-I 制造商:LSI Corporation 功能描述:STD CELL ASIC
L80227-I-LEADFREE 制造商:LSI Corporation 功能描述:796000124413