Figure 96 Internal and external connections diagramBaseband functional descriptionDigital baseband consists of ISA based modem and SYMBIAN based application sections. Modem functionalityis in RAP3G and Helen2/3 acts as a platform for SYMBIAN applications.Modem section consists of RAP3G ASIC with NOR FLASH and SDRAM memory as the core. RAP3G supports cellularprotocols of WCDMA (3GPP R-4) and GSM (minimum EDGE glass 10, GPRS phase2). Modem SDRAM memory have64Mbits of memory and NOR flash have 64Mbits of memory. RAP3G operates with the system clock of 38.4 MHz,which comes from the VCTCXO.Application section includes Helen3 ASIC with DDR/NAND combo memory as the core. Stacked DDR/NANDapplication memory has 512Mbits of DDR memory and 512Mbits of flash memory. Helen3 uses 19.2MHz clock,which comes from the RAP3G divided by two from the 38.4 MHz system clock.RM-42Nokia Customer Care System ModulePage 9–8 Company Confidential 9241872 (Issue 1)Copyright ©2005 Nokia. All Rights Reserved.