NSW-6
System Module SE2
PAMS Technical Documentation
Page 15
Issue 1 12/99
Nokia Mobile Phones Ltd.
MCU main features
System control
Cellular Software (CS)
Cellular Software communicates with the switching office, and
performs call build–up, maintenance and termination.
Communication control
M2BUS is used to communicate to external devices. This in-
terface is also used for factory testing, service and mainten-
ance purposes.
User Interface (UI)
PWR–key, keyboard, LCD, backlight, mic, ear and alert (buz-
zer, vibra, led) control. Serial interface from MAD to LCD
(same as for CCONT).
Authentication
Authentication is used to prevent fraud usage of cellular
phones.
RF monitoring
RF temperature monitoring by VCXOTEMP, ADC in CCONT.
Received signal strength monitoring by RSSI, ADC in CCONT.
False transmission detection by TXF signal, digital IO–pin.
Power up/down and Watchdog control
When power key is pressed, initial reset (PURX) has happened
and default regulators have powered up in CCONT, MCU and
DSP take care of the rest of power up procedures (LCD, COB-
BA, RF). The MCU must regularly reset the Watchdog counter
in CCONT, otherwise the power will be switched off.
Accessory monitoring
Accessory detection by EAD (HEADSETINT), AD–converter in
CCONT.
Battery and charging monitoring
MCU reads the battery type (BTYPE), temperature (BTEMP)
and voltage (VBAT) values by AD–converter in CCONT, and
phone’s operation is allowed only if the values are reasonable.
Charging current is controlled by writing suitable values to
PWM control in CCONT.
MCU reads also charger voltage (VCHAR) and charging cur-
rent values (ICHAR).
Production/after sales tests and tuning
Flash loading, baseband tests, RF tuning
Control of CCONT via serial bus