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المقسم الفرعي الآلي الخصوصي الهواتف متعددة المعالجه

المقسم الفرعي الآلي الخصوصي الهواتف متعددة المعالجه يتضمن DSP لأداء محددة لتجهيز نفسه لقنوات متعددة الخدمات الهاتفية ، في حين ان الحصول على اوامر من جهة اخرى (البلد المضيف) معالج...


The TMS320C54CST DSP features built-in telephony multi-processing algorithms such as DTMF generation and detection, Caller ID and Call Progress and Tone Detection, giving designers the ability to implement these features in cost-effective small office home office (SOHO) customer premise network equipment. Easy connection to an inexpensive telephony co-processor is made through the DSP's Host Port Interface (HPI), and all necessary telephony algorithms are included on-chip at no additional cost.

TI C54CST offers a complete, low-cost, one-stop-shopping solution for Telephony Multi-Processing applications. This C54x-based DSP encompasses Spirit Corporation's on-chip (ROM) algorithms for modem, telephony and voice functions. The C54CST combines the benefits of a programmable DSP and a Vocoder/Modem Chipset. The embedded voice algorithms are all eXpressDSP compliant, enabling other functions to be easily integrated and performed by the DSP. Additional software algorithms are available from Spirit Corporation.

Multiple Channel Echo Cancellation is an example of an application where multiple channels of voice and data are processed through a single algorithm, such as G.168 Echo Canceller or DTMF. In this example, a high frequency network channels are connected to a standard telephony system, requiring co-processing to remove background noise and echo. The C54CST is used as a Line Echo Canceling (LEC) chip, supporting 4 channels. Up to 16 channels of G.168 can run on C54CST, depending on the length of the echo tail. Here, the C54CST is operating in the Chipset Mode controlled by a host processor, utilizing only the on-chip ROM software. This software includes the G.168 algorithm.

Digital Signal Processor: TMS320C54CST

In Telephony Co-processing the C54CST is used for performing a single function on multiple channels, by using one or more of its on-chip ROMed algorithms for voice or telephony, along with the designer application code. The C54CST offers the following key advantages for Telephony Multi-processing:

Minimum design effort - in Chipset mode of operation, only the on-chip software runs on the C54CST. The DSP is controlled by a host processor, using AT parser commands via the UART. - allow you to concentrate on your add-on customized software while ensuring interoperability to the telephony algorithms.
Low cost solution - pricing includes both the DSP and on-chip software
Multiple channels - processing the same functionality on multiple streams.
Voice Algorithms:
VAD (Voice Activity Detection): detects presence of speech and adjusts level of noise in signal
AGC (Automatic Gain Control): amplifies voice signal ; works in conjunction with VAD
CNG (Comfort Noise Generator): generates small amount of noise to indicate live line
G.726: voice compression from 64kbps to selectable 16, 24, 32, or 40 kbps
G.711: converts u-law / A-law PCM signal to linear PCM (or vice versa)
G.168: Line ech cancellation (cancels ech tail length of 16 or 32 msec)
Telephony Algorithms:
DTMF (Dual-Tone Multi-Frequency) generation: generates touch tones
DTMF (Dual-Tone Multi-Frequency) detection: detects touch tone
CPTD (Call Progress Tone Detect): monitors progress on line (i.e. busy tone, dial tone)
CID Type 1/Type 2: Caller ID/Caller ID during call waiting
Data Algorithms:
V.32bis/V.32: 14.4/9.6 kbps modem
V.22bis/V.22: 2.4/ 1.2 kbps modem
V.42bis: data compression
V.42: data error correction

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