User Guide

CCS Technical Documentation Troubleshooting — BB

RH-48

Baseband Troubleshooting

RH-48 Baseband Module Overview

The Baseband module of the RH-48 transceiver is a CDMA single-band engine. The base-

band architecture is based on the DCT4 Apollo engine.

RH-48 cellular baseband consists of three ASICs: Universal Energy Management (UEM),

Universal Phone Processor (UPP), and a 128/8 megabit combo FLASH.

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

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

baseband. During the 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 phone 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.

RH-48 supports standard Nokia 2-wire and 3-wire chargers (ACP-x and LCH-x). How-

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

controlling the three-wire charger is ignored. UEM ASIC and EM SW control charging.

BL-5C Li-ion battery is used as main power source for RH-48. BL-5C has nominal capac-

ity of 850 mAh.