Specifications

AN93
110 Rev. 0.9
3.5.2. Voice Mode Example
Perform the following steps:
1. Connect hardware as shown in Figure 22. If using the Si3000 SSI EVB evaluation board, note that the Si3000
Evaluation Board requires an external 12-volt supply and derives 5 V power from the Si24xx-EVB. The Si24xx-
EVB should be connected to the supplied power adapter or powered through USB.
2. Enter the following AT commands to initialize the modem:
ATZ reset modem
ATE0 disable echo
AT:U0071,11 enable voice routing firmware
AT*Y254:W0059,7785 enable Si3000 Hardware Interface
In actual application, this line
must be implemented as a read-modify-
write consisting of the following:
n = AT*Y254:Q0059
n |= 1
AT*Y254:W0059,n
AT*Y254:W004B,011C Si3000 Reg 01 = 1C
This applies power to SPKRx,HDST,LINEO
AT*Y254:W004B,0545 Si3000 Reg 05 = 45
Enable HDST into ADC mixer
MIC input disabled
LINEI input disabled
AT*Y254:W004B,065D Si3000 Reg 06 = 5D
Activate HDST as output
Keep LINEO muted
0 db Receive Gain Setting
AT*Y254:W004B,075C Si3000 Reg 07 = 5C
0 dB Transmit Gain
Keep SPKRx muted
AT*Y0
3. Type "ATDTnnn", where nnn represents the telephone number of the remote telephone.
4. The remote phone rings and should be picked up.
5. Also pick up the local phone connected to the Si3000 Evaluation Board.
6. At this point, a voice connection exists between the two telephones.
7. It is also possible to send a series of single digit DTMF tones to the remote phone using the "AT.N" command
(dot character is in-between "AT" and "N", where N is a DTMF digit 0-9,A-F). The main reason for using the
"AT.N" instead of ATDT is that usage of AT.N ensures that carrier loss detection is not enabled inadvertently.
Using ATDT may result in a connection hang-up if the ambient noise is too low. Example:
AT.1 sends DTMF digit 1, return to voice mode.
8. Voice mode does not support T2CID, %V2, or overlap dialing.