Because of the digital radio TEA5768HL of the one piece – Engineering

July 17th, 2011 › immigration laws › admin ›

Summary: This text passes as well as introduces the application embodiment in the low-voltage MCS-51 system of digital radio of one piece represented by TEA5768HL, possess analyzed digital radio computer chip TEA5768HL application system design and software implement method of the one piece in detail, and put forward and used the handle method of the software to realize in which image frequency is caused problems with with, to tune the newest thinking of the broadcasting train station accurately to resist in the electronic radio. Keyword: I2C; MCU; PLL; The foreword regarding digital tuning TEA576x series monolithic nick digital radio is widely applied to the digital stereo, numbers such as walkie CD, VCD, DVD, mobile phone,etc. are consumed inside the electronic system. But not a bit very the same because of this electronic digital radio chip and tuning principle of the traditional superheterodyne stereo, the fixed intermediate rate of recurrence such as the traditional superheterodyne radio is 10.7Mz, and the fixed advanced frequency of TEA576x serial electronic radios is 225KHz, because repaired intermediate frequency is different, the program control of the phase locked loop system has a extremely great difference, this utilizes the artificer to bring certain difficulty for vast chip. This text directs against the manage mechanism of TEA576x serial electronic radio chips, the gentle hardware design of application detailing this chip is on such basis as MCS-51 one-chip computer in detail. TEA5768HL brief introduction TEA5768HL is a one piece stereosound FM electronic tuning radio suitable for the low-voltage environment. This chip completely integrated IF frequency assortment and frequency discrimination are usually systematic, and the low-cost peripheral ingredient that only needs to be few, the particular hardware system does not need debugging whatsoever. TEA5768HL signal forward end offers high-performance RF AGC circuit, receive high sensitivity, and compatible European, U.S.A. and also Japan FM frequency band. It’s flexible to consult frequency choice, can be set up and picked 32.768KHz, 13MHz crystal oscillator or 6.5MHz external clock reference rate of recurrence through the register. Carry on different functional control through I2C method bus, and pass Several IF counter value of I2C tour bus out. Complete free controlling of the demodulator of the stereosound, software manage SNC, HCC, suspends and quite function. Have got mouth of two prrr-rrrglable I/Os, can be used in other associative functions of the system.

The hardware implementation of TEA5768HL digital radio software system is shown as in Fig. One: The hardware module of TEA5768HL digital tuning radio program system is mainly by MCU(P89LPC932) Controlling routine, radio reception (TEA5768HL) of electronic tuning , audio frequency transmission amplification (TDA1308) 3 major elements make up. Among them MCU controlling routine is mainly formed by MCS-51 collection one-chip computers P89LPC932, keyboards and state cathode lewis tube terminals of reduced power consumption, it is the equipment platform of this application method, the keyboard is used for inputting various operation of the electronic tuning radio, various operating condition of the system are usually revealed by the state cathode ray tube terminal. At P89LPC932 with pairs of clock with regard to 80C51 kernel,it and if you can’t include, catch on-chip /comparing element, 2 analog comparators, I2C communication port, SPI communication port, keyboard interrupt feedback, real time clock, EEPROM storage area, resistance-capacitance oscillator and also watchdog’s timer on-chip,etc., can be suitable for the application of low-cost a lot of requirement higher integration density. Formed radio module of digital adjusting by TEA5768HL, audio frequency transmission amplification formed by TDA1308, end the audio frequency sign amplification of the digital adjusting radio. MCU control module surface finishes controlling all of the radio module of digital tuning through I2C bus line, the tone of voice signal that the radio module outputs is exported to the earphone or loudspeaker after amplifying via the amplification obstruct of audio frequency. The principle of TEA5768HL digital tuning radio reception module is actually shown as in Fig. 2.

The software design of TEA5768HL digital radio based on P89LPC932 one-chip computer control platform regarding application software framework of software program design mainly includes Several parts: 1. I2C bus line communication protocol, keyboard and also cathode ray tube terminal motorist program; 2. TEA5768HL bottom layer is driven, including the read/write procedure of control word of the register; 3. The application layer procedure includes the recognition of different application functions with the digital tuning radio. Employ software design whole the actual intersection of application layer and the intersection of computer software and main program by: System initiation, the intersection of keyboard command and diagnosis, system status information read and channel tune and the intersection of keyboard as well as command processing and systematic the intersection of scenario display and 6 deafening module make up. TEA5768HL digital focusing radio employs the main movement of program of the system software to be shown as in Fig. Several. The intersection of system initiation and including initialisation, I2C communication initialisation, method status information reading as well as TEA5768HL control register of P89 LPC932 initialisation included in this. One yard of recognizers regarding scanning and key about the keyboard, no longer go into information here, readers can finish through oneself. All functions tend to be opened by the input regarding keyboard, so the keyboard command processor will finish just about all functions of this system. Bring in the keyboard command processor associated with TEA5768HL digital radio especially the following. The keyboard command processor offers realized and suspended, guide search, automatic search, broadcast channel change, stereosound / the particular intersection of monophonic and also switch over, squelch muting and keyboard lock-up, each function is finished by a operate function. Each function is a function module function, key pad command processors are all the call of the function module function. In the above-mentioned 7 pieces of perform module, automatic search as well as manual search are secrets of the radio system program function module of this digital tuning. Automatic search the 4 way stop of function module and the intersection of function and also the intersection of automatic lookup and the intersection of function module and function through mainly: FM broadcast frequency setup, search for the frequency to presume, broadcast signal intensity to read, IFC intermediate frequency counter is read, the discrimination from the effective radio channel, transmit the machine format memory and system work situation exhibit of the channel etc. and made up partly. The function module function procedure with the automatic search is shown as in Fig. 4. Follow the method of Fig. 4 and create the function module associated with automatic search, will make the system well realize the automatic function of search, the manual lookup is equivalent to a search course of action frequency of the automatic lookup. Easy to find no matter automatic lookup or presume frequency manually, how it tunes single regularity to be key, also the particular algorithmic core of software the digital tuning radio tunes the broadcasting station. TEA5768HL term tunes the tuning how the radio system finished the single frequency by transferring the function function. Tune the function module function of the only frequency and tune the particular function module function of the single frequency to include: Frequency and machine format conversion (track the algorithm function) regarding phase locked loop , TEA5768HL songs the optimization choices as well as TEA5768HL control register write operation of arrangement, High/Low Injection with the state register.

TEA5768HL digital tuning radio is a Digital Focusing System to conclude the speech. Besides the hardware platform, completely depend on MCU control on its register can finish all capabilities of the digital tuning stereo. On the basis of the application system associated with TEA5768HL, the hardware design of trustworthy performance is a foundation, the nice software framework is a important, and choose optimally on the basis of High/Low Shot of software control and the machine format accurate transformation of phase locked loop can guarantee the system runs continuously more reliably.

Bibliographical reference One Philips Semiconductors TEA5768HL Datasheet, 20022 Philips Semiconductors P89LPC932 Datasheet, User Manual, 2002 Several Philips Semiconductors. Digital Radio Specification. Faithful plum of 20004 horses,etc.. Language C application programming from the one-chip computer. Beihang University publishing home, 1999