ISD-T360SB Datasheet, PDF (93/109 Pages) List of Unclassifed Manufacturers – VoiceDSP Digital Speech Processor with Master/Slave, Full-Duplex Speakerphone, Multiple Flash and ARAM/DRAM Support

2—SOFTWARE
ISD-T360SB
Table 2-5: TUNABLE PARAMETERS: Tone Generation and Message Playback
Index
Parameter Name
Description
Default
27
DTMF Generation:
A one-byte value that controls the twist level of a DTMF tone, 66
DTMF_GEN_TWIST_LEVEL generated by the GT command, by controlling the energy
level of each of the two tones (low frequency and high
frequency) composing the DTMF tone. The Least Significant
Nibble (LSN) controls the low tone and the Most Significant
Nibble (MSN) controls the high tone. The energy level of each
tone, as measured at the output of a TP3054 codec (before
the DAA) connected to the VoiceDSP processor is summarized
in the following table:
Nibble Value
Tone Energy (dB-Volts)
0
0
1
–17.8
2
–14.3
3
–12.9
4
–12.4
5
–12.0
6
–11.9
7
–11.85
8..15
–11.85
The volume of the generated DTMF tone during
measurements was 6. (TONE_GEN_LEVEL+VOL_LEVEL = 6).
For the default level, the high tone is –14.3 dBV and the low
tone is –12.4 dBV, which gives a DTMF twist level of 1.9 dB.
The energy level of a single generated tone is the level of the
low tone.
16
Tone Generation:
TONE_GEN_LEVEL
Controls the energy level at which DTMF and other tones are 6
generated. Each unit represents 3 dB. The default level is the
reference level.
For example, if you set this parameter to 4, the energy level is
6 dB less than the default level. The actual output level is the
sum of TONE_GEN_LEVEL and the VOL_LEVEL variable,
controlled by the VC command. The tones are distorted when
the level is set too high.
Legal values: 0 ≤ TONE_GEN_LEVEL + VOL_LEVEL ≤ 12.
21
VCD Playback and
Controls the energy during playback and external voice
6
Voice Synthesis:
synthesis. Each unit represents 3 dB. The default level is the
VCD_PLAY_LEVEL
reference level.
For example, if you set this parameter to 4, the energy level is
6 dB less than the default level. The actual output level is the
sum of VCD_LEVEL and the VOL_LEVEL variable, controlled by
the VC command. Speech is distorted when the level is set
too high.
Legal values: 0 ≤ VCD_PLAY_LEVEL + VOL_LEVEL ≤ 12.
ISD
2-53