Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 20 of 92 21.12.2001
2.4 GSM baseband processor
The GSM baseband processor handles all the processing for audio, signaling and data
transfer within a GSM cellular device. Internal software runs the application interface and the
whole GSM protocol stack. A UART forms the interface to the cellular device application.
The GSM baseband processor is a single chip mixed signal baseband IC, containing all
analog and digital functionality of a cellular radio. Designed to meet the increasing demands
of the GSM/PCS cellular subscriber market, it supports FR, HR and EFR speech and
channel coding without the need for external hardware.
Its high level of integration reduces system complexity, board dimensions and the number of
components. In combination with the RF solution a complete two-chip GSM system solution
is achieved, which results in extremely compact implementation, very low power
consumption and cost effective system performance. Due to its very flexible interfaces the
baseband controller can easily be set up to control a wide variety of RF architectures. The
baseband processor is powered by a C166 CPU and a DSP processor core. Integrating
these high performance processor cores with on-chip memory, a TDMA timer module and
GSM specific peripherals provides a compelling single chip cellular baseband processor.
2.4.1 Features of the GSM baseband processor
The baseband processor includes the following major features:
• C166 MCU processor core
• Digital Signal Processing core
• On-chip MCU Program ROM / SRAM flexibly configurable as program or data RAM
• DSP Program ROM / RAM
• DSP Data ROM / RAM
• Programmable PLL for system clock generation
• GSM Timer Module that off-loads the MCU from radio channel timing
• MCU and DSP Timers
• Pulse Carry Modulation output for Automatic Frequency Correction (AFC)
• Serial RF Control Interface
• ISO 7816 compatible SIM card interface
• Digital and analog voiceband and baseband filters including digital-to-analog and
analog-to-digital converters
• RF power ramping functions
• Measurement of battery voltage, battery and environment temperature
• GMSK Modulator
• Viterbi Hardware Accelerator
• A51/A52 Cipher Unit
• Comprehensive static and dynamic power management