Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 193)

AN93
Rev. 1.3 193
7.3.3.5. TAM PSTN
This mode is used to answer an incoming call with OGM playback and ICM recording. The caller may perform local
TAM operations (i.e. record OGM, review ICM) via remote DTMF control. The modem is off-hook routing audio
between the DAA and the DTE interface; however, audio is also available at the Si3000 (via UB5 path) so call
screening is possible via the speaker (LINEO) while the microphone is muted. The modem voice path is configured
for half-duplex audio with the speakerphone algorithm disabled. Side tone is disabled. Handset TX/RX coefficients
are applied. The Si3000 is using the LINEI and LINEO signals with speakerphone gain settings. This mode is
supported by the Si2418/29/36/38 parts.
Figure 31. System Voice Modes
Handset
Speakerphone
TAM
Hands-Free
TAM
PSTN
Initialize
RIN
G
(An
swe
r O
n)
On-
Hoo
k
Eve
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(nu
me
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S
P
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ise
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on
On
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et
R
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Han
dse
t
Rais
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ven
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SP B
utton
Off E
vent
(Han
dset
Off-
Hoo
k)
TAM
Handset
H
an
ds
et
Lo
w
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o
r
Ab
or
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ve
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Us
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Re
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