
CCS Technical Documentation
BB Troubleshooting
Company Confidential
NEM-4
Issue 1 09/2003
Copyright
2003 Nokia Corporation
Page 6(a)-19
Company Confidential
Clocks Troubleshooting
Clocks include the following:
RF-clock
ADSP Clock
DBUS, CBUS clocks
Flash and SDRAM clocks
Sleep clock
Bluetooth clock
SIM clock
MMC clock
NEM-4 has three external oscillators for baseband clocking. The main clock is generated
by 26MHz oscillator (B601) and routed through Mjoelner RF ASIC to UPP_WD2 engine
ASIC. Sleep Clock is generated by 32kHz oscillator to UEM, which then supplies it to
UPP_WD2, Bluetooth module and FM radio chip. The third oscillator generates 12MHz
clock for ADSP and AIC. UPP_WD2 uses the system clock to generate various clocks for
different purposes.
Figure 1: Clock diagram
System clock can be measured from the lower pad of capacitor C171. This clock should
be running when phone is on.
In SLEEP mode the VCXO is off. UEM generates low frequency clock signal (32.768 kHz)
that is fed to UPP_WD2, Bluetooth and ZOCUS.
MMC Clock
CBus Clock
Sleep Clock
DBus Clock
SIM Clock
RFConvClock
12MHz
Oscillator
MMC
Nectar
Bluetooth
Mjoelner
UPPWD2
UEM
SIM
Zocus
Flash
Amadeus
Audio
Codec
VCXO
26MHz
RFClk
SysClk
SDRClk
Audio
Clock
SIM
Clock
Flash
Clock
SDRAM
RFBusClk
FM Clock
Buffer