参数资料
型号: PEF22508E
厂商: INFINEON TECHNOLOGIES AG
元件分类: 数字传输电路
英文描述: DATACOM, PCM TRANSCEIVER, PBGA256
封装: 17 X 17 MM, 1 MM PITCH, PLASTIC, LBGA-256
文件页数: 165/193页
文件大小: 10683K
代理商: PEF22508E
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页第125页第126页第127页第128页第129页第130页第131页第132页第133页第134页第135页第136页第137页第138页第139页第140页第141页第142页第143页第144页第145页第146页第147页第148页第149页第150页第151页第152页第153页第154页第155页第156页第157页第158页第159页第160页第161页第162页第163页第164页当前第165页第166页第167页第168页第169页第170页第171页第172页第173页第174页第175页第176页第177页第178页第179页第180页第181页第182页第183页第184页第185页第186页第187页第188页第189页第190页第191页第192页第193页
Data Sheet
73
Rev. 1.0, 2005-06-02
OctalLIU
TM
PEF 22508 E
Functional Description
to TCLK is automatically performed if CMR6.ATCS = 1. All switchings of XCLK between TCLK and the DCO-
X output are shown in the interrupt status bit ISR7.XCLKSS0 which is masked by IMR7.XCLKSS0. These
kinds of switching cannot be done in general without causing phase jumps in the transmit clock XCLK.
Additionally after loss of TCLK the transmit clock XCLK is also lost during the “detection time” for loss of TCLK
and the transmit pulses are disturbed. If CMR6.ATCS is cleared, TCLK is used (again) as source for the
transmit clock XCLK, independent if TCLK is lost or not. The interrupt status bit ISR7.XCLKSS0 will be set also.
If the transmit clock XCLK is sourced by the DCO-X output and the DCO-X reference clock is TCLK, the DCO-
X reference will be switched automatically (if CMR6.ATCS = 1) to FCLKX (see multiplexer “F” in Figure 29)
after a loss of TCLK was detected. If the DCO-X reference was switched to FCLKX and TCLK becomes active,
switching of the reference (back) to TCLK is automatically performed if CMR6.ATCS = 1. All switchings of the
reference between TCLK and FCLKX are shown in the interrupt status bit ISR7.XCLKSS1 which is masked by
IMR7.XCLKSS1. For these kinds of automatically switching, the transmit clock XCLK fulfills the jitter-, wander-
and frequency deviation- requirements as specified for E1/T1 after the clock source of the DCO-X was
changed. If CMR6.ATCS is cleared, TCLK is used (again) as reference for the DCO-X, independent if TCLK
is lost or not. The interrupt status bit ISR7.XCLKSS1 will be set also.
The status register bits CLKSTAT.TCLKLOS and CLKSTAT.FCLKXLOS (CLKSTAT) show if the appropriate
clock is actual lost or not, so together with ISR7.XCLKSS1 and ISR7.XCLKSS0 the complete information
regarding the current status of the transmit clock system is provided.
3.9.4
Transmit Jitter Attenuator
The transmit jitter attenuator is based on the so called DCO-X (digital clock oscillator, transmit) in the transmit path.
Jitter attenuation of the transmit data is done in the transmit elastic buffer, see Figure 29. The DCO-X circuitry
generates a "jitter-free" transmit clock and meets the E1 requirements of ITU-T I.431, G. 736 to 739, G.823 and
ETSI TBR12/13 and the T1 requirements of AT&T PUB 62411, PUB 43802, TR-TSY 009,TR-TSY 253, TR-
TSY 499 and ITU-T I.431, G.703 and G. 824. The DCO-X circuitry works internally with the same high frequency
clock as the DCO-R. It synchronizes either to the working clock of the transmit system interface (internal transmit
clock) or the clock provided on multi function pin TCLK or the receive clock RCLK (remote loop/loop-timed). The
DCO-X attenuates the incoming jitter starting at its corner frequency with 20 dB per decade fall-off. With the jitter
attenuated clock, which is directly depending on the phase difference of the incoming clock and the jitter
attenuated clock, data is read from the transmit elastic buffer (512/386 bit) or from the JATT buffer (512/386 bit,
remote loop), see Figure 31. Wander with a jitter frequency below the corner frequency is passed transparently.
The dual transmit elastic buffer can buffer two data streams so that dual rail mode is possible at the transmit framer
interface (XDIP/XDIN).
The DCO-X is equivalent to the DCO-R so that the principle for its configuring is the same, see Figure 23 and
The DCO-X reference clock is monitored: If one, two or three clock periods of the 2.048 MHz (1.544 MHz in T1/J1
mode) clock at FCLKX are missing the DCO-X regulates its output frequency. If four or more clock periods are
missing
The DCO-X circuitry is automatically centered to the nominal frequency of 2.048 MHz (1.544 MHz in T1/J1) if
the center function of DCO-X is enabled by CMR2.DCOXC = 1.
The actual DCO-X output frequency is “frozen” if the center function of DCO-R is disabled by
CMR2.DCOXC = 0.
The jitter attenuated clock is output on pin XCLK if the transmit jitter attenuator is enabled, see multiplexer “H” in
The transmit jitter attenuator can be disabled. In that case data is read from the transmit elastic buffer with the
clock sourced on pin TCLK, see multiplexer “H” in Figure 29. Synchronization between FCLKX and TCLK has to
be done externally.
In the loop-timed clock configuration (LIM2.ELT) the DCO-X circuitry generates a transmit clock which is frequency
synchronized on RCLK, see Figure 31 and multiplexers “G” and “F” in Figure 29. In this configuration the transmit
elastic buffer has to be enabled.
相关PDF资料
PDF描述
PEF22554E DATACOM, FRAMER, PBGA160
PEF22554HT DATACOM, FRAMER, PQFP144
PES12-42S-N0024
PESD3V3V4UK,132 25 W, UNIDIRECTIONAL, 4 ELEMENT, SILICON, TVS DIODE
PF38F3050L0YUQ3A SPECIALTY MEMORY CIRCUIT, PBGA88
相关代理商/技术参数
参数描述
PEF22508EV1.1-G 功能描述:网络控制器与处理器 IC T/E RoHS:否 制造商:Micrel 产品:Controller Area Network (CAN) 收发器数量: 数据速率: 电源电流(最大值):595 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PBGA-400 封装:Tray
PEF22508EV11G 制造商:Rochester Electronics LLC 功能描述: 制造商:Infineon Technologies AG 功能描述:
PEF22508EV11GXP 制造商:Lantiq 功能描述:LINE INTERFACE UNITS
PEF22508EV11GXT 制造商:Lantiq 功能描述:LINE INTERFACE UNITS
PEF22509EV1.1 制造商:Infineon Technologies AG 功能描述:SP000205605_T/E ASIC_TY_PB