Connector Default Configuration; Accessory Detection - Siemens SXG 75 Service Repair Documentation

16.3 Connector default configuration

When no accessory is present, the accessory connector must be configured to a specific default
state. This default state only applies when the phone is switched on or when the phone stays in
charge mode.
The default values are shown below:
Pin
1
2
3
4
5
6
7
8
9
10
11
12
Accessory connector configuration
"Z" means the driver is in high impedance state.

16.4 Accessory detection

When initially connected to SXG75, the accessory type must be determined. This is achieved by
monitoring the following signals:
• MSM_UART1_RXD
• MSM_UART1_CTS_N
• MSM_UART1_RFR_N
• MSM_UART1_DCD_N
The MSM6250 must set these signals to be inputs with no internal pull-up/downs if no accessory is
connected.
The RX line has an external pull-down; the CTS, RFR, and DCD lines have an external pull-up. The
MSM6250 must also set the USB/UART switch to connect the TX/RX pins on the connector to the
UART.
When an accessory is connected, the MSM6250 detects a change in state on one or more of the
lines. The lines may be pulled high, low, or connected to the TX line in order to identify the
accessory. Once the accessory is recognised, the accessory connector signals are configured
appropriately.
Technical Documentation
TD_Repair_L3_SXG75_R1.0.pdf
Signal Default Level
POWER L (Z)
GND GND
TX H (Z)
RX L (Z)
CTS H (Z)
RTS H (Z)
DCD H (Z)
AUDIO_L Z
AUDIO_REF Z
AUDIO_R Z
EXT_MIC_GN
GND
D
EXT_MIC Z
Company Confidential
2006©BenQ
Default Direction
off
/
out (Z)
in
in
in
In
Off
Off
Off
/
Off
Release 1.0
01/2006
Page 68 of 73