參數(shù)資料
型號: PEB2445-N
廠商: SIEMENS A G
元件分類: 路由/交換
英文描述: Multipoint Switching and Conferencing Unit - Attenuation MUSAC-A
中文描述: TELECOM, CONFERENCING CIRCUIT, PQCC44
封裝: PLASTIC, LCC-44
文件頁數(shù): 25/70頁
文件大小: 1236K
代理商: PEB2445-N
PEB 2445
Functional Description
Semiconductor Group
25
02.96
stored in the CCM include the input time-slot and line number, the associated
conference number as well as the noise suppression thresholds and the attenuation
levels. The conference number defines a unique location in the Conference Sum
Memory (CSM) used to store the accumulated samples for each conference. The
Conference Sum Memory is alternately loaded in the first half of the frame and unloaded
in the following second half. In the first half the input samples are processed to
implement the noise suppression, the expansion according to the European A-law or the
US
μ
-law and the attenuation function. The Data Memory (DM) buffers these samples
for output processing. The CSM is used to accumulate these samples and store the
resulting sum. During output processing the input sample is retrieved from the Data
Memory and the appropriate sum from the Conference Sum Memory for subtraction, so
that the channel output signal contains the contribution of all the other channels in the
conference except its own. After output attenuation and PCM compression, the data are
written in the Speech Memory for output switching.
If one result of the subtractions exceeds the full scale value, a saturation appears and
the MUSAC-A signals this conference overflow condition by an interrupt. The conference
number of the conference in overflow is buffered in the Conference Status Register
(CST) which can be retrieved by the external controller.
A tone to be inserted into a conference is handled as an additional conference
subscriber using any input PCM channel (access to CCM) but without assigning an
output time-slot (no access to CM).
Multipoint Switching is a special form of conferencing for data communication. In the
multipoint switching mode several terminals are connected together. Normally only one
should transmit at a time; its signal is distributed to the other terminals. For collision
detection purposes all input signals are summed up to construct the output signal. In
contrast to audio conferences terminals broadcast data to the MUSAC-A which are only
‘or-connected’. That is, at each bit time, the ‘conference sum’ is ‘1’ if the input of one or
more terminals is ‘1’; otherwise, the result is ‘0’. The data memory, the subtractor, the
linearization and attenuation are of no use in this mode. The general procedure is the
same as for conferencing.
All attenuations of the PCM values are calculated by the following mechanism
1. Expansion according CCITT Rec. G. 711
2. Attenuation by
lin. value
×
2
– (x/6)
, x = Attenuation
3. Comparison according CCITT Rec. G. 711
These functions are implemented by a PLA/ROM.
The chip architecture makes it possible to decrease the delay between incoming and
outgoing PCM channels. The processed input samples are transmitted either in the
same frame or in the next frame at the latest.
相關(guān)PDF資料
PDF描述
PEB2445N LTM4600 Evaluation Kit
PEB2447 Memory Time Switch Extended Large MTSXL
PEB2447H Memory Time Switch Extended Large MTSXL
PEB2466 Four Channel Codec Filter with PCM- and m-Controller Interface SICOFI4-mC
PEB2466-HV1.2 Four Channel Codec Filter with PCM- and m-Controller Interface SICOFI4-mC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PEB2445P 制造商:未知廠家 制造商全稱:未知廠家 功能描述:PCM, Other/Special/Miscellaneous
PEB2447 制造商:INFINEON 制造商全稱:Infineon Technologies AG 功能描述:Memory Time Switch Extended Large MTSXL
PEB2447H 制造商:INFINEON 制造商全稱:Infineon Technologies AG 功能描述:Memory Time Switch Extended Large MTSXL
PEB2447HV1.2 制造商:Rochester Electronics LLC 功能描述:- Bulk
PEB2447H-V12 功能描述:IC SWITCH MEM TIME CMOS 100-MQFP RoHS:否 類別:集成電路 (IC) >> 接口 - 專用 系列:* 特色產(chǎn)品:NXP - I2C Interface 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:2 通道 I²C 多路復(fù)用器 接口:I²C,SM 總線 電源電壓:2.3 V ~ 5.5 V 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:剪切帶 (CT) 安裝類型:表面貼裝 產(chǎn)品目錄頁面:825 (CN2011-ZH PDF) 其它名稱:568-1854-1