Nokia NEM-4 Series Troubleshooting Instructions page 21

CCS Technical Documentation
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.
Audio
Clock
12MHz
Oscillator
VCXO
26MHz
Mjoelner
SysClk
Bluetooth
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.
Issue 1 09/2003
Company Confidential
Amadeus
Buffer
MMC Clock
Audio
Codec
RFClk
RFBusClk
UPPWD2
Flash
SDRClk
Clock
SDRAM Flash
Figure 1: Clock diagram
Copyright  2003 Nokia Corporation
Company Confidential
MMC
Nectar
RFConvClock
SIM Clock
DBus Clock
Sleep Clock
CBus Clock
Zocus
NEM-4
BB Troubleshooting
FM Clock
UEM
SIM
Clock
SIM
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