Siemens C55 Repair Documentation

V1.20 Page 25 of 48 ICM MP CCQ GRM
A55/C55_Hitachi Company Confidential © Copyright Siemens AG 04/03
The DSP part contains:
• DSP signal processor
• Separate program/data memory
• a hardware block for processing the RX signal,
• a hardware block for “ciphers“,
• a hardware block for processing the linguistic signal,
• a hardware block for the “GMSK modulator“,
• De-/ interleaving memory,
• Communication memory
• a PLL for processing and reproducing the VCXO pulse signal.
In the DSP Firmware are implemented the following functions:
• scanning of channels, i.e., measurement of the field strengths of neighbouring
base stations
• detection and evaluation of Frequency Correction Bursts
• equalisation of Normal Bursts and Synchronisation Bursts
• channel encoding and soft-decision decoding for fullrate, enhanced-fullrate and
adaptive multirate speech, fullrate and halfrate data and control channels.
• channel encoding for GPRS coding
• fullrate, enhanced fullrate and adaptive multirate speech encoding and decoding
• mandatory sub-functions like
– discontinuous transmission, DTX
– voice activity detection
– background noise calculation
• generation of tone and side tone
• hands-free functions
• support for voice memo
• support for voice dialling
• loop-back to GSM functions
• GSM Transparent Data Services and Transparent Fax
• calculation of the Frame Check Sequence for a RLP frame used for GSM
NonTransparent Data Services
• support of the GSM ciphering algorithm
Real Time Clock (integrated in the EGOLD+):
The real time clock is powered via a separate voltage regulator inside the Power
Supply ASIC. Via a capacitor, data are kept in the internal RAM during a battery
change for at least 30 seconds. An alarm function is also integrated with which it is
possible to switch the phone on and off.
5.1.4 SRAM
Memory for volatile data
Memory Size: 4 Mbit
Data Bus: 16Bit
5.1.5 FLASH
Memory Size: 64Mbit (8 Mbyte)
Data Bus: 16 Bit
5.1.6 SIM
SIM cards with supply voltages of 1.8V and 3V are supported.

Siemens C55 Specifications

General

Brand	Siemens
Model	C55
Category	Cell Phone
Language	English