Version: 1.18
PRELIMINARY/CONFIDENTIAL
TrueSpeech® Co-Processor
9.7.10.1
Threshold Level Scale
The threshold level scale is relative to the maximum positive full-scale value of 7FFFH (decimal 32767). This
corresponds to an input signal level of approximately + 3dBm0 from the external µ-law CODEC.
The precise input signal level scale can be calculated thus:
Input Level in dBm0 = +3.17 - 20 log(base 10) ( (input level/32767) * 256/240)
so the default threshold level of 0100H = 256 decimal, corresponds to 44.753 dBm0.
To calculate the actual average input signal level, read the LEVEL from the device and then perform the following
calculation:
CORRECTED LEVEL = (LEVEL * 256)/240
Input level in dBm0 = 3.17 - 20 * log10( CORRECTED LEVEL/32767)
CT8022A11AQC FW Revision 0118 DSP GROUP, INC., 3120 SCOTT BOULEVARD
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All specifications are subject to change without prior notice.
ETC [ ETC ]
