User Guide

Nokia Customer Care Baseband Description and Troubleshooting

2118 (RH-77)

Introduction

The baseband module is a CDMA single-band engine based on the DCT4 architecture and

consists of three ASICs: Universal Energy Management cost effective (UEMC), Universal

Phone Processor (UPP8M4.2), and a 64 megabit FLASH.

The baseband architecture supports a power-saving function called sleep mode. Sleep

mode shuts off the VCTCXO, which is used as the system clock source for both the RF and

the baseband. During sleep mode, the system runs from a 32 kHz crystal and all the RF

regulators (VR1A, VR1B, VR2, … VR7) are off. The sleep time is determined by network

parameters. Sleep mode is entered when both the MCU and the DSP are in standby mode

and the normal VCTCXO clock is switched off. The mobile terminal is waken up by a timer

running from this 32 kHz clock supply. The period of the sleep/wake up cycle (slotted

cycle) is 1.28N seconds, where N= 0, 1, 2, depending on the slot cycle index.

2118 supports standard Nokia 2-wire and 3-wire chargers (ACP-x and LCH-x). However,

the 3-wire chargers are treated as 2-wire chargers. The PWM control signal for

controlling the 3-wire charger is ignored. UEMC ASIC and EM SW control charging.

BL-5C Li-ion battery is used as main power source and has nominal capacity of 850 mAh.