NHL-10
CCS Technical Documentation
Baseband Troubleshooting
10
COMPANY CONFIDENTIAL
ISSUE 2 01/2004
Copyright © 2003 Nokia. All Rights Reserved.
Baseband serial interface troubleshooting
CBUS
CBUS is a three wire serial interface between the main baseband components. The bus con-
sists of data, clock and bus_enable signals. In NHL-10 the bus is connected from UPP_WD2
to UEM and the BT module. UPP_WD2 takes care of controlling the traffic on the bus.
If the interface is faulty from the UPP WD2's end the phone will not boot properly as powering
configurations do not work. Traffic on the bus can be monitored from three pins on the BT mod-
ule.
Pins are shown below.
Figure 6: CBUS test points
CBUS traffic is shown in the figure below (Read command to Zocus, LM3819, N380).
CbusClk is connected to Ch1, Cbus Da to Ch2 and CbusEnx to Ch3.