Siemens C75 - Page 27

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Copyright 2005© Siemens AG
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Service Repair Documentation
Level 2.5e – C75
Release 1.0
7.1.2.8 USB Charging
The ASIC can support USB charging when USB charging is integrated in the charging
software. If charge voltage is in the range 4.4V to 5.25 V USB charging is ongoing. During
USB charging only limited charging is possible. Charge current is limited to 75, 150, 300 or
400 mA.
7.1.2.9 Audio multiplexer
The digital audio information from/to the DSP inside the SGOLD are delivered via the I2S
interface, the 26MHz from the RF part. The internal AD and DA converter are connected to
microphone and loudspeaker.
DSP
MCU
I/O-Connector
MIC2
Mozart / Twigo 4
MONO1_OUT
MICBIAS
I²C / TWI
SSC
MONO2_OUT
Vibra
PWM
RINGIN
MONO1_LP_OUT
MONO2_LP_OUT
MONO1_IN
MONO2_IN
HP
SPK
STEREO1_OUT
STEREO1_OUT
PHANTOM_BUFF_OUT
MUX
MIC1
LINE2
LINE1
I²S
MUX
I²S
MICE2
MICE1
HP
MIC
HP
MICE
M
I²S
Control
...
26MHz
DAC
ADC
PLL
DIV
DIV
I²S_1
EP2
MIC1
MIC2
RINGIN
I²S_1
MUX
VMIC
NB
ADC
Decoder
Encoder
I²C / TWI
SSC
EP1
LP Filter
SGold lite
KEY-CLICK
&Ringing
I²S_2
I²S_2
NB
DAC
BB
GSM
RF
GSM
BB & RF
Bluetooth
Voice
Recording
DAC
ADC
I/O-Connector
Mono Headset
I²S
HP
MICBIAS
7.1.2.10 Interface
The ASIC has two serial control interfaces and one serial audio interface. With the serial
interfaces, all functions of the ASIC can be controlled. For time critical commands ( all audio
functions incl. Vibra) the SSC is used.
TWI interface
TWI ( two wire interface) is an I2C 2 wire interface with the signals Clock (I2C_CLK) data line
(I2C_DAT) and the interrupt (PM_INT).