User Manual
Table Of Contents
- Document History
- Introduction
- Product Concept
- GSM Application Interface
- GSM/GPRS Operating Modes
- Power Supply
- Power Up / Down Scenarios
- Automatic GPRS Multislot Class Change
- Charging Control of the GSM Part
- Power Saving
- Summary of State Transitions (Except SLEEP Mode)
- RTC Backup for GSM Part of XT55/56
- Serial Interfaces of the XT55/56 GSM Part
- Audio Interfaces
- SIM Interface
- Control Signals
- GPS Application Interface
- GSM and GPS Antenna Interfaces
- Electrical, Reliability and Radio Characteristics
- Mechanics
- Reference Approval
- Example Applications
- List of Parts and Accessories
XT55/56 Hardware Interface Description
Confidential / Preliminary
s
XT55/56_hd_v02.96 Page 25 of 125 18.08.2005
2.2 Circuit Concept
The XT55/56 module comprises the following major functional components:
GSM / GPRS baseband block:
• Baseband controller operating at 26MHz
• Power supply ASIC
• Stacked Flash / SRAM
• Application interface (board-to-board connector)
GSM RF block:
• RF transceiver
• RF power amplifier / FEM
• Antenna connector
GPS block:
• Processor type: ARM7/TDMI
• Processor speed: depending on GPS software, e.g. 12.277MHz for the standard GPS
software supplied by Siemens
GPS RF block:
• GPS receiver with SiRFstar Ile/LP chip set