User Guide

Nokia Customer Care Troubleshooting - Baseband

6015/6015i/6016i/6019i (RH-55), 6012 (RM-20)

The charger recognition is initiated when the EM SW receives a "charger connected"

interrupt. The algorithm basically consists of the following three steps:

1. Check that the charger output (voltage and current) is within safety limits

2. Identify the charger as a 2-wire or 3-wire charger

3. Check that the charger is within the charger window (voltage and current)

If the charger is accepted and identified, the appropriate charging algorithm is initiated.

Figure 15: Charging circuit

Charge Control

In active mode, charging is controlled by the UEM's digital part. Charging voltage and

current monitoring is used to limit charging into a safe area. For that reason, the UEM

has the following programmable, charging cut-off limits:

• VBATLim1=3.6 V (Default)

• VBATLim2L=5.0 V

• VBATLim2H=5.25 V

VBATLim1, 2L, 2H are designed with hystereses. When the voltage rises above VBATLim1,

2L, 2H+ charging is stopped by turning the charging switch off. There is no change in the

operational mode. Charging restarts after the voltage decreases below VBATLim-.

Audio

The audio control and processing is supported by the UEM and the UPP. The UEM

contains the audio codec. The UPP contains the MCU and DSP blocks, handling and

processing the audio data signals.

The baseband supports three microphone inputs and two earpiece outputs. The

microphone inputs are:

• MIC1 = Used for the phone's internal microphone

• MIC2 = Used for pop-port audio accessories

• MIC3 = Used for the Universal Headset

Every microphone input can have either a differential or single-ended AC connection to

the UEM circuit. The internal microphone (MIC1) and external microphone (MIC2) are

both differential for Tomahawk accessory detection. However, the Universal Headset

interface is single-ended. The microphone signals from different sources are connected