Connector Signals; Vc-20-Mr2 Dtmf Tone Data - Digital Voice Systems VC-20-MR2 User Manual

D V S
IGITAL OICE YSTEMS,
The Speech Compression Specialists
VFXI is the analog speech input which is filtered with a 100 Hz. - 3700 Hz.
bandpass filter and then input to the encoder via a 16 bit linear codec. In order to
VRXI
avoid clipping VRXI must not exceed +/- 1.5 volts.
3.5 VC-20-MR2 on-board jumpers Connector Signals
Jumper
3.6

VC-20-MR2 DTMF Tone Data

The VC-20-MR2 supports dtmf detection, transmission, and generation. The
encoder detects and transmits dtmf tones, and the decoder decodes and generates
dtmf tones, in support of standard telephony requirements
In addition, if the VC-20 encoder detects a dtmf tone it activates the DTMF_DET
signal for four clock cycles of TXCK and simultaneously outputs (LSB first) four
bits of data on DTMF_DAT which identify the dtmf tone which was detected. The
DTMF_DET flag is only output once for each continuous dtmf tone that is detected.
The correspondence between the data bits and dtmf tone is shown in Table 1.
VC-20 AMBE™ Vocoder Board User's Manual
I
NC.
Signal
1 Connects on-board 4.8/2.4 kHz data clock to TXCK
2 Connects on-board 4.8/2.4 kHz data clock to RXCK
Connects on-board 20 ms frame clock to FMEN
3
4 Connects on-board 20 ms frame clock to FMDE
5 Connects TXD to RXD0 (LSB)
6 Connects TXD to RXD1
Connects TXD to RXD (MSB)
7
8 reserved (leave unconnected)
9 reserved (leave unconnected)
10 reserved (leave unconnected)
11 Deactivates LOST signal
12 Connects ENSLNCE to DESLNCE signal
13 reserved (leave unconnected)
14 reserved (leave unconnected)
Section 6 – Advanced Features
page 15