YTD428_07 Datasheet, PDF (15/28 Pages) YAMAHA CORPORATION – IDSU ISDN DSU for Terminal Equipment

DETAILS OF FUNCTIONS
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4. DETAILS OF FUNCTIONS
4.1 U Reference Point Section
s Variable Amplifier
This block amplifies the receive signal amplitude to the maximum dynamic range.
s ADC
This block makes an A/D conversion of the received signal and transfers it to the line termination block.
s Peak Hold
This block is performed during the initial training so that the gain of the Variable amplifier block is set to
make best communication condition.
4.2 Circuit Termination / Line Termination Section
s Circuit Termination Block
The following functions provide the necessary functions for TTC Standard JT-G961 (TCM operation) and the
NT function described in TTC Standard JT-I430.
q _{Rate adaptation and frame assembly / disassembly at the U and T reference points}
q _{State transition control}
q _{U reference point drive control}
q _{T reference point receive timing control}
q _{Loopback control}
YTD428 supports loopback 2 and loopback C for testing and maintenance.
These loopback tests are under local switch control.
s Line Termination Block
The line termination provides the f equalization which compensates the DLL (Digital Local Line) loss and the
amplitude distortion, and the BT equalization which compensates the waveform distortion caused by the
bridged tap.