PSB21383H Datasheet, PDF (154/270 Pages) Infineon Technologies AG – Siemens Codec with S/T Transceiver

PSB 21381/2
PSB 21383/4
Description of the programmable parameters:
Codec
Parameter
GLE
GDSLE
PDSLE
GDNLE
PDNLE
ETLE
# of CRAM
Bytes
1
1
1
1
1
1
Range
– 48 to + 48 dB
0 to 48 dB
0.16 to 42 ms/dB
0 to 48 dB
0.16 to 42 ms/dB
0 to 1020 ms
Comment
Gain of Line Echo
Reserve when speech is detected
Peak Decrement
when speech is detected
Reserve when noise is detected
Peak Decrement
when noise is detected
Echo time
4.4.4.3 Automatic Gain Control of the Transmit Direction (AGCX)
Optionally an AGCX is inserted into the transmit path (see figure 83) to reach nearly
constant loudness ratings independent from the varying distance between the speaking
person and the microphone. The AGCX works only together with the speakerphone
function (GCR.SP=1).
Operation of the AGCX depends on a threshold level. The threshold is defined by the
parameter COMX (value relative to the maximum PCM-value). Regulation follows two
time constants: TMHX for signal amplitudes above the threshold and TMLX for
amplitudes below. Usually TMHX will be chosen up to 10 times faster than TMLX. The
bold line in figure Chapter 84 depicts the steady-state output level of the AGCX as a
function of the input level.
Data Sheet
144
2001-03-12