Hardware interfaces
Version 8 dated 15.03.00
22
Siemens Information and Communication Products
Signal description on the 9-pole D-sub DCE connector:
Signal connection 9-pole D-sub DCE to M20 80-pole SMD connector:
4.3.6
Additional RX/TX interface
This interface is reserved for Siemens development internal purposes.
4.3.7
Voiceband serial ports/digital audio interface (DAI)
To provide a digital audio interface to the user and to offer high-end echo suppression in handsfree environments as an
upgrade feature, the on-board voiceband serial connector between the M20 microcontroller and codec (A/D device) is con-
nected to the 80-pole SMD connector.
Note
: the data exchanged on the interface involves 13 bit linear PCM at 8000 samples per second.
Note
: in normal cases, the voiceband serial ports (to microcontroller and to codec) have to be interconnected on the PCB
of the base unit.
If using the DAI, connection to the codec-oriented ports is not necessary.
For handsfree applications, see detailed information in Chapter
8.8.5 “Adding echo suppression functionality” on page 200
9-pole D-Sub
DCE Pin No
Description
Function
CCITT
V-24
EIA
RS232
DIN
66020
I/O DCE to
DTE
1
DCD
Data Carrier Detect
109
CF
M5
O
2
RXD
Receive Data
104
BB
D2
O
3
TXD
Transmit Data
103
BA
D1
I
4
DTR
Data Terminal Ready
108
CD
S1
I
5
GND
Ground
102
AB
E2
6
DSR
Data set ready
107
CC
M1
O
7
RTS
Request to send
105
CA
S2
I
8
CTS
Clear to send
106
CB
M2
O
9
RI
Ring Indication
125
CE
M3
O
DCE Pin No
DCE Signal
M20 Signal
M20 Pin No
1
DCD
DCD
54
2
RXD
USCTX
72
3
TXD
USCRX
10
4
DTR
DSR
26
5
GND
6
DSR
DTR
16
7
RTS
USCCTS
9
8
CTS
USCRTS
73
9
RI
USCRI
11
Signal
Function
I/O
Level
Comments
RXDATA
Receive data
I
2.8 V
if unused, connect to signal RES#
TXDATA
Transmit data
O
2.8 V
may be disconnected if unused
Signal
Function
I/O
Level
Comments
VSFS_C
Synchronisation
I
2.8V
to microcontroller (in normal cases, to be connected to VSFS_V)
VSCLK_C
Clock
I
2.8V
to microcontroller (in normal cases, to be connected to VSCLK_V)
VSDO_C
Data output
O
2.8V
to microcontroller (in normal cases, to be connected to VSDI_V)
VSDI_C
Data Input
I
2.8V
to microcontroller (in normal cases, to be connected to VSDO_V)