RH-21
Troubleshooting
CCS Technical Documentation
Page 8
Nokia Corporation Confidential
Issue 1 05/2003
Figure 1: Power-up sequence
1 Power key pressed
•
After 20ms, UEM enters RESET MODE if VBAT>Vmstr+
•
VFLASH1, Vana, Vcore, Vio, and VR3 goes high
•
VCTCXO enabled by VR3 -> RFClk 19.44 MHz running
2 Purx released
•
Purx released by UEM, UEMINT goes high for 100 ms, SleepX
goes high, and SleepClk (32 KHz) starts running.
3 Software running
•
Default value for Vcore is 1.5 volts and, if software is running, Vcore
will rise to 1.8 volts
•
Cbus (1.08MHz) and Dbus clocks start running
Phone does not start up normally or does not stay on
Note: In the case of power-up faults, it is not possible to force the phone on by disabling the watchdog.
Instead, measurements should be taken immediately when the power key is pressed or when the bat-
tery voltage is connected to the phone (local / test mode).
The easiest way to check if the software is running when the phone takes an abnormal
amount of current is to measure the
cbusclk
and
Vcore
.
The Dbus clock (programmable 9.72MHz) is not automatically visible in the test and local
modes.
