CN109874087A - The application of CCB bussing technique in HTIB system - Google Patents

Abstract

I2S be PHILIPS Co. between digital audio-frequency apparatus audio data transmission and formulate a kind of bus standard, it is very widely used in HTi B system.In HTi B system, need to decide whether to open PCM1800 sometimes；Mainly pass through setting Audio CTL register (2000d008h) for the switch of PCM1800 to realize, such as mvd [audioctl] |=0x20, namely by the position AREN in Audio CTL register, the function of opening PCM1800 is thus realized；By setting mvd, [audioctl] &=~0x20, which is realized, closes PCM1800 function；In HTi B system, due to being integrated with the function of radio, control and data transmission are carried out between reception signals tuning chip this requires realizing main control chip and carrying out, therefore, system introduces CCB bus.

Description

The application of CCB bussing technique in HTIB system

Technical field

The signal of I2S format of the invention no matter how many valid data, the highest order of data always occur from SCK change At the 2nd SCK pulse after changing (namely a frame starts).This allows for receiving end and the number of significant digit of transmitting terminal can not Together；If the number of significant digit that receiving end can be handled is less than transmitting terminal, low data extra in data frame can be abandoned；If connect The number of significant digit that receiving end can be handled is more than transmitting terminal, can voluntarily supply remaining position, this synchronization mechanism makes digital audio The interconnection of equipment is more convenient, and not will cause data dislocation.

Background technique

As digital audio system is being gradually introduced sound equipment consumption market, such as CD, DVD, DTV etc., these Digital audio and video signals in system need to be handled by many chips, such as carry out D/A and A/D conversion, digital signal Processing etc.；How standard connection is carried out between these audio systems to ask at what chip manufacturer and equipment commercial city were paid special attention to Topic under the conditions of this herein, has developed a kind of for digital sound series connection bus I2S；In I2S format, any equipment is all Main equipment can be served as, during carrying out data transmission between devices, the equipment for serving as main equipment generates SCK and WS letter Number, after obtaining SCK and ws signal from equipment, SD signal is sent to main equipment.

Summary of the invention

In HTi B system, the chip used for the conversion of Δ ∑ audio D/A is solution of the invention PCM1606 just teaches how to realize the conversion of Δ ∑ audio D/A by PCM1606 in HTi B system below；Δ ∑ audio Digital-to-analogue or analog-to-digital conversion mainly use noise shaping sampling technique, that is, make quantizing noise point with Δ ∑ quantizer It is scattered to other than signal band, inhibits the noise in signal band, reach high-precision；Core for audio system noise reduction technology is " first properly increasing i.e. the treble components of program " exacerbation is aggravated/postemphasises " then to record, the signal-to-noise ratio of high frequency just improves , but for signal, it is at this moment the phenomenon that there is frequency distortions, in order to compensate for this distortion in playback again high pitch Component, which is suitably decayed, " to postemphasis ", and the overshoot part in such program is just calmed down, high-frequency noise during postemphasising It is attenuated together, so the signal-to-noise ratio of high band obtains and improves.

Specific embodiment

Present invention implementation is as follows, when the analog signal of audio is input to PCM1800, by the modulation of Δ ∑, digital filtering etc. Process exports digital audio and video signals under the control of mode and system clock；In PCM1800, there is a mode/format control Interface processed uses MODEO, MODE1 as mode selection pin in the interface, and FMT0, FMT1 select pin as output format； ES6028 provides the I2S interface of standard, and realizes the interconnection with PCM1800 chip by this interface；Specifically by mould Quasi- signal is handled, and then interconnects the digital signal of output and the respective pins of ES6028；By Audio RCV register (0x2000d010h) is set as OxaO, is meant that finger is carried out data transmission using the data format of I2S, in transmission process, The transmission for first carrying out MSB, is triggered in failing edge.

Claims (1)

1. CCB bus of the invention is a kind of bus standard of Sanyo (SANYO) company, the address of bus is all by SANYO Managing performance, the function of radio receiver in HTiB system is realized, needs to use the bus standard；CE signal is the enabled letter of chip Number, when CE signal wire is set to high level, it can permit serial data output or serial date transfer；DI is data The serial data signal come from controller transmission can be input in LC72131 by input signal cable；DO is data output signal The serial signal come from LC72131 transmission can be output in controller by line；CL is synchronizing clock signals, serial when carrying out When data input or output, synchronizing clock signals are used it as.