Nokia NSB-7 Series, Руководство по обслуживанию

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NSB-7
System Module PAMS Technical Documentation
Page 8 ã Nokia Mobile Phones Ltd. Issue 1 06/00
System Module
Baseband Module
The ASICs are in the uBGA package. Flash and SRAM chips are inside the same package.
EEPROM is software emulated with Flash. These changes have decreased the number of
I/O between the ICs. Smaller I/O count has made using smaller packages possible
The baseband architecture supports a power saving function called ”sleep mode”. This
sleep mode shuts off the VCTCXO, which is used as system clock source for both RF and
baseband. During the sleep mode the system runs from a 32 kHz crystal. The phone is
waken up by a timer running from this 32 kHz clock supply. The sleeping time is deter-
mined by some network parameters. The sleep mode is entered when both the MCU and
the DSP are in stand-by mode and the normal VCTCXO clock has been switched off.
The battery charging is controlled by a PWM signal from the CCONT. The PWM duty cycle
is determined by a charging software and is fed to the CHAPS charging switch.
Two types of chargers can be connected to the phone. Standard chargers (two wires)
provide a coarse supply power, which is switched by the CHAPS for suitable charging
voltage and current. Advanced chargers (three wires) are equipped with a control input.
Three wire chargers are treated like two wire ones.
Block Diagram
Figure 1: Block Diagram
CCONT
UI
SIM
MAD
CHAPS
COBBA
BATTERY
PA SUPPLY
RF SUPPLIES
BB SUPPLY
TX/RX SIGNALS
BASEBAND
VBAT
+
MEMORIES
COBBA SUPPLY
EXT. AUDIO
IR
32kHz
CLK
13MHz
CLK
SLEEP CLOCK
SYSTEM CLOCK
HS-connector
Charger
connector