Research And Design On Set-stop Boxes Position Lock And Download System

The GSM technology is investigated at first。 And then the system framework and workingprinciple of the RF and the baseband of GSM handset are introduced in detail,on this basis,Further analyzing the MTK6225platform provided by MediaTek Taiwan,the hardware design and debugging of GSM mobile phone at this platform are proposed.The study in this paper is as follows:1. Details of the circuit and working principle of the MT6225platform. Including the baseband circuit, RF circuit of two parts. The Baseband include:the storage part of、the serial part、the part of the SIM card、boot circuit part together with the design schematics. The RF section introduces the MT6139RF chip, which uses radio frequency low-IF architecture. The basic module contains the antenna、RF connector、 SAW filter and antenna matching circuit、 power amplifier、crystal oscillator.Understanding of the overall RF draw a basic schematic diagram of the RF module and the external matching circuit.2. MTK provides software development kit (modify the corresponding drive can easily be ported to their system is very convenient for secondary development, greatly improving the reusability of software development cost and time savings), detailed description of the softwareplatform for secondary development interfaces needed in the part of the MMI structure and development process. MMI on the AT command module、base station search module、memory module、download the software design of the module.3. Different from the previous design is also an additional a bootloader minimum system used to communicate with the set-top box as an intermediate interface.In this paper, the set-top box position to lock the download system has a simple、reliable、 small size、easy to upgrade、just the serial port can be used accurately set-top box position lock to ensure that the use of set-top boxes in the service area approved specification set-top box service regional marketsand accelerate the process of information in rural areas is of great significance and broad market prospects.