Fig. 8-8 Handsfree Application Diagram - Siemens M20 Terminal Technical Description

Siemens Information and Communication Products
8.8.5 Adding echo suppression functionality
39 42 40 41
SPN
SPP
M ICN M ICP
Fig. 8-8 Handsfree application diagram
The example depicted above makes use of the M20 internal voiceband codec. The M20 is controlled by the HOST via the
AT commands. The HOST is also responsible for booting and controlling the handsfree DSP. If an external voiceband
codec is to be used, the serial link between the DSP and the internal codec (VSFS_C, VSCLK_C, VSDI_C, VSDO_C)
must be omitted and the external codec has to be linked to the DSP.
Note: External clock signalling is not possible in this configuration.
A handsfree DSP can be ordered, for example, from Analog Devices: AD2186L. For further information please contact
Analog Devices (http://www.analog.com/).
8.8.6 Ignition line
1
4
6
T o M20T
W hen using M20T
Implement as shown
Power supply: 8-24V
Fig. 8-9 Ignition line
Version 8 dated 15.03.00
69
68
67
M20
66
12
13
14
15
10 72
USCTX_
USCRX_
AT-Commands
HOST
W hen using M20
80 pole SMD Connector:
Power supply DC IN: 6V
Pins:
DC IN(6V): 18-22, 58-62
IG NITIO N: 8
G ND: 17, 23-25, 38, 43, 56
VSFS_V
SFS1
VSCLK_V
SCLK1
VSDO_V
SDO1
VSDI_V
SDI1
VSFS_C
SFS2
VSCLK_C
SCLK2
VSDI_C
SDO2
VSDO_C
SDI2
1 +
4 G ND
From Power supply
57, 63-65
Application notes
DSP
Host-Interface
A
200