The Ideal " />
參數(shù)資料
型號(hào): XRT75R12DIB-L
廠商: Exar Corporation
文件頁(yè)數(shù): 4/133頁(yè)
文件大小: 0K
描述: IC LIU E3/DS3/STS-1 12CH 420TBGA
標(biāo)準(zhǔn)包裝: 40
類(lèi)型: 線路接口裝置(LIU)
驅(qū)動(dòng)器/接收器數(shù): 12/12
規(guī)程: DS3,E3,STS-1
電源電壓: 3.135 V ~ 3.465 V
安裝類(lèi)型: 表面貼裝
封裝/外殼: 420-LBGA 裸露焊盤(pán)
供應(yīng)商設(shè)備封裝: 420-TBGA(35x35)
包裝: 托盤(pán)
第1頁(yè)第2頁(yè)第3頁(yè)當(dāng)前第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)
XRT75R12D
97
REV. 1.0.3
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
The Ideal Case (e.g., with no frequency offsets)
The 44.736Mbps + 1 ppm Case
The 44.736MHz - 1ppm Case
Throughout each of these cases, we will discuss how the resulting "bit-stuffing" (that was done when mapping
the DS3 signal into SONET) affects the amount of intrinsic jitter and wander that will be present in the DS3
signal, once it is ultimately de-mapped from SONET.
8.2.2.1
The Ideal Case for Mapping DS3 data into an STS-1 Signal (e.g., with no Frequency
Offsets)
Let us assume that we are mapping a DS3 signal, which has a bit rate of exactly 44.736Mbps (with no
frequency offset) into SONET. Further, let us assume that the SONET circuitry within the PTE is clocked at
exactly 51.84MHz (also with no frequency offset), as depicted below.
Given the above-mentioned assumptions, we can state the following.
The DS3 data-stream has a bit-rate of exactly 44.736Mbps
The PTE will create 8000 STS-1 SPE's per second
In order to properly map a DS3 data-stream into an STS-1 data-stream, then each STS-1 SPE must carry
(44.736Mbps/8000 =) 5592 DS3 data bits.
Is there a Problem?
According to Figure 44, each STS-1 SPE only contains 5589 bits that are specifically designated for "DS3 data
bits". In this case, each STS-1 SPE appears to be three bits "short".
No there is a Simple Solution
No, earlier we mentioned that each STS-1 SPE consists of nine (9) "Stuff Opportunity" bits. Therefore, these
three additional bits (for DS3 data) are obtained by using three of these "Stuff Opportunity" bits.
As a
consequence, three (3) of these nine (9) "Stuff Opportunity" bits, within each STS-1 SPE, will carry DS3 data-
bits. The remaining six (6) "Stuff Opportunity" bits will typically function as "stuff" bits.
In summary, for the "Ideal Case"; where there is no frequency offset between the DS3 and the STS-1 bit-rates,
once this DS3 data-stream has been mapped into the STS-1 data-stream, then each and every STS-1 SPE will
have the following "Stuff Opportunity" bit utilization.
3 "Stuff Opportunity" bits will carry DS3 data bits.
6 "Stuff Opportunity" bits will function as "stuff" bits
FIGURE 45. A SIMPLE ILLUSTRATION OF A DS3 DATA-STREAM BEING MAPPED INTO AN STS-1 SPE, VIA A PTE
PTE
44.736MHz + 0ppm
DS3_Data_In
STS-1_Data_Out
51.84MHz + 0ppm
相關(guān)PDF資料
PDF描述
XRT75R12IB-L IC LIU E3/DS3/STS-1 12CH 420TBGA
XRT75VL00DIV IC LIU E3/DS3/STS-1 1CH 52TQFP
XRT75VL00IV-F IC LIU E3/DS3/STS-1 1CH 52TQFP
XRT79L71IB-F IC LIU/FRAMER DS3/E3 1CH 208BGA
XRT81L27IV-F IC LIU EI 7CH 3.3V 128TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XRT75R12ES 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 12CH T3/E3/STS1LIUJA 3.3V W/REDUNDANCY RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel
XRT75R12IB 功能描述:外圍驅(qū)動(dòng)器與原件 - PCI 12CH E3/DS3/STS W/JITTER R3 TECH RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray
XRT75R12IB-F 功能描述:外圍驅(qū)動(dòng)器與原件 - PCI 12 Channel 3.3V-5V temp -45 to 85C RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray
XRT75R12IB-L 功能描述:LIN 收發(fā)器 Attenuator RoHS:否 制造商:NXP Semiconductors 工作電源電壓: 電源電流: 最大工作溫度: 封裝 / 箱體:SO-8
XRT75VL00 制造商:EXAR 制造商全稱(chēng):EXAR 功能描述:E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR