CN100508446C - Digital Audio Signal transmission system and method - Google Patents
Digital Audio Signal transmission system and method Download PDFInfo
- Publication number
- CN100508446C CN100508446C CNB2005101304857A CN200510130485A CN100508446C CN 100508446 C CN100508446 C CN 100508446C CN B2005101304857 A CNB2005101304857 A CN B2005101304857A CN 200510130485 A CN200510130485 A CN 200510130485A CN 100508446 C CN100508446 C CN 100508446C
- Authority
- CN
- China
- Prior art keywords
- digiverter
- digital audio
- frequency
- signal
- transmission system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 40
- 230000005236 sound signal Effects 0.000 title claims abstract description 24
- 238000000034 method Methods 0.000 title claims abstract description 7
- 238000005096 rolling process Methods 0.000 claims description 3
- 230000001360 synchronised effect Effects 0.000 claims description 3
- 101000821096 Homo sapiens Synapsin-2 Proteins 0.000 description 3
- 102100021994 Synapsin-2 Human genes 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 101000821100 Homo sapiens Synapsin-1 Proteins 0.000 description 2
- 102100021905 Synapsin-1 Human genes 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000009365 direct transmission Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
Images
Abstract
The transmission system of disclosed digital audio signal is in use for lowering noise in procedure for transmitting and plying back audio data. Through a counter, the transmission system controls D/A converter in control system so as to overcome the issue brought by inconsistent of working clock rate between unit of sending audio data and D/A converter. The invention keeps certain proportional relation between working clock rate of D/A converter and data input frequency in whole procedure for transmitting and playing back audio data. Thus, audio signal can be played back sharply.
Description
Technical field
The present invention relates to field of data transmission, particularly the transmission of digital audio-frequency data.
Technical background
For digital audio processor, more satisfactory is to integrate functions such as audio decoder, Audio Processing, digital-to-analogue conversion, but the common cost of the chip of this integrated-type is very high, and if one of them functional module cisco unity malfunction also can have influence on the operation of other devices.Therefore, at present common way is by the dispensing device with audio decoder or audio recording function, has the receiving system of Audio Processing function, and digiverter and corresponding bus are formed an audio transmission system together.
As shown in Figure 1, dispensing device T sends data transfer clock signal SCK, track selecting signal WS to receiving system R, and digital audio-frequency data SD.Through the processing of receiving system R, digital audio-frequency data DATA is sent to digiverter DAC.Simultaneously, receiving system R produces synchronizing signal SYN according to the change frequency (being the sample frequency Fs of voice data) of WS, and SYN is sent to described digiverter DAC.
Shown in Fig. 2 A, in each cycle of data transfer clock SCK, there is a digital audio-frequency data SD to be sent to receiving system R.Track selecting signal WS has defined the sound channel of playing digital audio and video signals, and for example, digital audio and video signals will be play by R channel when WS is high level, and digital audio and video signals will be play by L channel when WS is low level.Shown in Fig. 2 B, digiverter DAC just reads in a treated voice data DATA when synchronizing signal SYN is high level, so the frequency of SYN has determined the data incoming frequency of DAC.As seen generally, the sampled audio signal frequency Fs of dispensing device T is consistent with the data incoming frequency Fs ' of digiverter DAC.
Digiverter DAC is that the relation between the working clock frequency Fmclk ' of DAC data incoming frequency Fs ' and DAC has clear and definite requirement for the frequency of synchronizing signal SYN, Fmclk '=256*Fs ' for example, Fmclk '=384*Fs ', Fmclk '=512*Fs '.With configuration different selections can be arranged according to different DAC, but in a single day this proportionate relationship is fixed up, and does not allow to change in the voice playing process.When voice data when dispensing device T sends, the operating frequency Fmclk of dispensing device T and audio data samples frequency Fs satisfy above-mentioned relation.As previously mentioned, audio sampling frequency Fs is consistent with the data incoming frequency of DAC, therefore, if keep the stable proportionate relationship of above-mentioned Fmclk ' and Fs ' just to require the working clock frequency of dispensing device T and receiving system R necessary identical.But, because dispensing device T and receiving system R are two separate operational modules, therefore their working clock frequency can not guarantee identical, Fmclk '/Fs can not keep fixing value so, normally periodically change, what this will cause that DAC can not be correct reduces to voice data, and will introduce a large amount of noises.
The way that addresses the above problem in the prior art directly sends to digiverter DAC with the work clock signal of dispensing device T by receiving system R as shown in Figure 3A.But, be not that all chips all have enough pins to support the direct transmission of this kind clock signal.
The way of another kind of prior art is shown in Fig. 3 B, because data transmission system clock signal SCK is handled through frequency division by the work clock of dispensing device T to obtain, therefore in described audio transmission system, increase by a phase-locked loop circuit PLL the received data transfer clock signal SCK of receiving system R is carried out frequency multiplication, thereby obtain consistent working clock frequency, and with its operating frequency as described digiverter DAC with described dispensing device T.But adopt described phase-locked loop circuit PLL will make the cost of whole system increase greatly.
Therefore, also there is not a kind of lower cost solution that can solve dispensing device T work clock and the inconsistent problem of receiving system R work clock at present.
Summary of the invention
The objective of the invention is under the prerequisite that improves chip cost not significantly, solve in the Digital Audio Transmission process owing to dispensing device work clock and the inconsistent problem of introducing a large amount of noises of digiverter work clock.
The invention provides a kind of digital Audio Signal transmission system, comprise dispensing device, receiving system and digiverter, also comprise a counter; Described dispensing device sends data transfer clock signal, track selecting signal and digital audio-frequency data to described receiving system; Described receiving system transmits treated digital audio-frequency data to described digiverter; Described counter produces a synchronous signal by counting described digiverter is controlled, and when described rolling counters forward during to a predetermined value, the treated digital audio-frequency data that comes from described receiving system is read into described digiverter.Wherein, the long-pending working clock frequency that equals described digiverter of described predetermined value and described synchronous signal frequency.
Aforesaid digital Audio Signal transmission system can also comprise a MUX.Wherein, described counter produces the input signal of synchronizing signal one as described MUX by counting, and described receiving system produces synchronizing signal two another input as described MUX according to the track selecting signal; Under the control of the synchronizing signal three that described MUX is exported, the treated digital audio-frequency data that comes from described receiving system is read into described digiverter.Wherein, the long-pending working clock frequency that equals described digiverter of described predetermined value and described synchronizing signal one frequency.
Aforesaid dispensing device can be an audio decoding apparatus, and receiving system can be an apparatus for processing audio, and the bus of audio transmission can be I
2S bus, digital audio-frequency data wherein can be serial data or parallel data.In addition, described predetermined value can require to determine according to described digiverter.
The present invention also provides a kind of digital audio and video signals transmission method that carries out, and comprising: the operating frequency with digiverter is the counting operation of count frequency; And the operation of when counting down to a predetermined value, just digital audio-frequency data being sent into digiverter.
Technical solution of the present invention does not influence under the prerequisite of system cost in the number of pins that does not increase chip yet, and it is inconsistent and introduce the problem of noise to have solved voice data dispensing device and digiverter work clock.
Description of drawings
Fig. 1 is traditional digital Audio Signal transmission system structure chart;
Fig. 2 A is the signal timing diagram of dispensing device to the receiving system transmission;
Fig. 2 B is a digiverter data-interface working timing figure;
Fig. 3 A solves dispensing device work clock and the inconsistent digital Audio Signal transmission system structure chart of digiverter work clock in the prior art;
Fig. 3 B solves dispensing device work clock and the inconsistent another kind of digital Audio Signal transmission system structure chart of digiverter work clock in the prior art;
Fig. 4 A is the digital Audio Signal transmission system structure chart that technical solution of the present invention is put down in writing;
Fig. 4 B is the another kind of digital Audio Signal transmission system structure chart that technical solution of the present invention is put down in writing;
Fig. 5 adopts the different technologies scheme to reduce the audio signal comparison diagram that obtains.
Embodiment
The present invention has adopted a kind of new Digital audio frequency signal transmission system for realizing aforementioned goal of the invention.In this transmission system, shown in Fig. 4 A, the synchronizing signal SYN of control digiverter DAC reading of data is produced by a counter C, and the count frequency of this counter C is identical with the working clock frequency Fmclk ' of described digiverter DAC.When described counter C count down to a certain predetermined count value, C just sent a pulse signal to digiverter DAC, and then DAC reads in a voice data DATA.A certain predetermined numerical value described here can be decided according to different DAC, and for example 256,384,512 etc.
The course of work of the digital Audio Signal transmission system that the present invention put down in writing can further specify by following example.The working clock frequency Fmclk=12.288MHz of for example described dispensing device T, audio sample rate Fs=48KHz, the relation between them satisfies Fmclk=256*Fs.But, working clock frequency Fmclk '=12.00MHz of described receiving system R and described digiverter DAC.If it is consistent with the sample frequency Fs of dispensing device T that the data incoming frequency Fs ' of digiverter DAC still keeps, the situation that will occur Fmclk ' ≠ 256*Fs ' in whole audio transmission process, what this will cause that DAC can't be correct reduces to audio signal.In order to address this problem, in original digital Audio Signal transmission system, added counter C, be responsible for producing the synchronizing signal SYN of control digiverter DAC by C.The count frequency of counter C is configured to the operating frequency Fmclk ' of described digiverter DAC.Like this, when the integral multiple that count down to 256, counter C just sends a pulse to digiverter DAC, and DAC just reads in a voice data.Like this, although the work clock of dispensing device T and receiving system R and incomplete same has still kept the fixed proportion of Fmclk '=256*Fs ' to concern in whole audio transmission process.
An alternative embodiment of the invention has increased a MUX M between said counting device C and digiverter DAC shown in Fig. 4 B.One of the input of this MUX M SYN1 is from described counter C.The count frequency of this counter C is configured to the operating frequency Fmclk ' of described digiverter DAC.Another input SYN2 of described MUX M comes from described receiving system R, and the frequency of SYN2 is the sample frequency Fs of dispensing device T.Such audio data transmission system structure provides the space that can select for the user, and when the working clock frequency of the working clock frequency of dispensing device T and digiverter DAC not there are differences, MUX M selected to allow SYN2 pass through; When the working clock frequency of dispensing device T is different with the working clock frequency of digiverter DAC, MUX M select to allow SYN1 by and control digiverter DAC reading to voice data.
Fig. 5 is for adopting the audio signal oscillogram of being exported by digiverter DAC before and after the technical solution of the present invention.Wherein, waveform l is for original table sample audio signal, and waveform 2 is represented under the dispensing device T situation different with the working clock frequency of digiverter DAC, the audio signal that reduction obtains through DAC.Can see since in whole audio transmission process the proportionate relationship of Fmclk ' and Fs ' therefore have a large amount of noises in the audio signal that reduction obtains through DAC in continuous variation.Resulting audio signal after the technical scheme that the present invention put down in writing has been adopted in waveform 3 representative, although as seen because the incoming frequency Fs ' of DAC thus have certain reduction to produce small discontinuous on some euphonic minor variations and the waveform compared to the sample frequency Fs of dispensing device T, but because the difference of Fmclk and Fmclk ' is very small, therefore these differences that caused all belong to people's ear can not identification minor variations.
Being used for the bus of transmitting audio data in the foregoing description can be I
2The S bus also can be other bus that is used for audio transmission.Voice data SD can be that the voice data of serial also can walk abreast.
The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement etc., all should be included within protection scope of the present invention.
Claims (8)
1. a digital Audio Signal transmission system comprises dispensing device, receiving system and digiverter, it is characterized in that described transmission system also comprises a counter;
Described dispensing device sends data transfer clock signal, track selecting signal and digital audio-frequency data to described receiving system;
Described receiving system transmits treated digital audio-frequency data to described digiverter;
Described counter produces a synchronous signal by counting described digiverter is controlled, make when described rolling counters forward during to a predetermined value, the treated digital audio-frequency data that comes from described receiving system is read into described digiverter, the long-pending working clock frequency that equals described digiverter of the frequency of described predetermined value and described synchronizing signal.
2. a digital Audio Signal transmission system comprises dispensing device, receiving system and digiverter, it is characterized in that described transmission system also comprises a counter and a MUX;
Described dispensing device sends data transfer clock signal, track selecting signal and digital audio-frequency data to described receiving system;
Described receiving system transmits treated digital audio-frequency data to described digiverter;
Described rolling counters forward produces the input signal of first synchronizing signal as described MUX during to a predetermined value, described receiving system produces another input as described MUX of second synchronizing signal according to described track selecting signal, the long-pending working clock frequency that equals described digiverter of the frequency of described predetermined value and described first synchronizing signal;
Described MUX is first of input, select one of them output as the 3rd synchronizing signal in second synchronizing signal, when the working clock frequency of the working clock frequency of described dispensing device and described digiverter not there are differences, described MUX selects described second synchronizing signal as described the 3rd synchronizing signal, when the working clock frequency of the working clock frequency of described dispensing device and described digiverter there are differences, described MUX selects described first synchronizing signal as described the 3rd synchronizing signal, under the control of described the 3rd synchronizing signal, the treated digital audio-frequency data that comes from described receiving system is read into described digiverter.
3. transmission system as claimed in claim 1 or 2 is characterized in that described dispensing device is an audio decoding apparatus.
4. transmission system as claimed in claim 1 or 2 is characterized in that described receiving system is an apparatus for processing audio.
5. transmission system as claimed in claim 1 or 2, the bus that it is characterized in that carrying out the digital audio-frequency data transmission is I
2The S bus.
6. transmission system as claimed in claim 1 or 2 is characterized in that digital audio-frequency data is serial data or parallel data.
7. transmission system as claimed in claim 1 or 2 is characterized in that described predetermined value determines according to described digiverter requirement.
8. method of carrying out digital audio and video signals transmission based on the described digital Audio Signal transmission system of claim 1 comprises:
Working clock frequency with digiverter is the counting operation of count frequency;
When counting down to described predetermined value, just digital audio-frequency data is sent into the operation of digiverter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101304857A CN100508446C (en) | 2005-12-13 | 2005-12-13 | Digital Audio Signal transmission system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101304857A CN100508446C (en) | 2005-12-13 | 2005-12-13 | Digital Audio Signal transmission system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1777088A CN1777088A (en) | 2006-05-24 |
| CN100508446C true CN100508446C (en) | 2009-07-01 |
Family
ID=36766421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005101304857A Expired - Fee Related CN100508446C (en) | 2005-12-13 | 2005-12-13 | Digital Audio Signal transmission system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100508446C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100533552C (en) * | 2007-07-03 | 2009-08-26 | 北京中星微电子有限公司 | Digital audio frequency controller |
-
2005
- 2005-12-13 CN CNB2005101304857A patent/CN100508446C/en not_active Expired - Fee Related
Non-Patent Citations (2)
| Title |
|---|
| 数字音频信号的传输与同步. 刘勇.现代电视技术，第2期. 1996 |
| 数字音频信号的传输与同步. 刘勇.现代电视技术，第2期. 1996 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1777088A (en) | 2006-05-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9461812B2 (en) | Increased bandwidth encoding scheme | |
| US5577044A (en) | Enhanced serial data bus protocol for audio data transmission and reception | |
| CN110248285B (en) | Multi-channel audio equipment | |
| JP4851942B2 (en) | Equipment with improved serial communication | |
| US10560780B2 (en) | Phase alignment in an audio bus | |
| CN100527802C (en) | Multiplexed analog-to-digital converter arrangement | |
| CN110749763A (en) | Triggering method based on I2S signal and oscilloscope | |
| CN101577618B (en) | Transmission apparatus and method | |
| CN100508446C (en) | Digital Audio Signal transmission system and method | |
| CN110888619A (en) | Digital audio power amplifier synchronization circuit and method and electronic equipment | |
| US10476659B2 (en) | SPDIF clock and data recovery with sample rate converter | |
| US7454543B2 (en) | Early high speed serializer-deserializer (HSS)internal receive (Rx) interface for data sampling clock signals on parallel bus | |
| KR19990072628A (en) | Audio playback apparatus | |
| US8848849B1 (en) | SPDIF clock and data recovery with sample rate converter | |
| CN113986130A (en) | High-capacity high-speed multichannel data playback equipment and method | |
| CN201449727U (en) | Conversion device based on field programmable gate array | |
| US9355558B2 (en) | High bandwidth configurable serial link | |
| CN102148920B (en) | Synchronizing signal amplitude limiting device and method | |
| CN208768200U (en) | A kind of monitoring device | |
| KR100200736B1 (en) | Micom interface apparatus | |
| CN112765066B (en) | Bridge module for serdes interface | |
| US20220070586A1 (en) | Audio signal processing chip, multichannel system, and audio signal processing method | |
| EP2581903B1 (en) | Systems and methods for reducing audio disturbance associated with control messages in a bitstream | |
| CN110519667B (en) | Method for realizing optical signal line crossing | |
| CN100412747C (en) | Method for providing digital audio frequency I2S interface clock |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090701 Termination date: 20111213 |