The role of DSP audio processor

      With the increasing degree of electric and electric control in automobile application, digital signal processing will be all over every corner of the automobile.In the automobile signal processing system, high efficiency and energy saving and high speed operation play a great role in the overall performance.DSP is a specialized processor designed to handle highly intensive repetitive data.The traditional processor is far from the speed of DSP processor, in terms of functionality is not much better than the application of high-tech DSP processor.

      Traditionally, GPP uses a Von Neumann memory structure, where programs and data share a memory space and a common set of buses (address bus and a data bus) are linked to the processor core.Today, though, a typical high-performance GPP contains two on-chip caches (one data, one instruction) directly connected to the processor core to speed up access at runtime.The wide application of new technology has brought tuning into a new era, bringing a whole new experience to the field of perfect sound quality.It marks the end of the distortion of the old generation of audio processors.Unbeatable signal-to-noise ratio and ultra-low distortion are the result of technological innovation. DSP audio processors can be operated by a computer with ease.

At present, there are not many DSP audio processors in the market, and there are only one or two DSP audio processor products launched by major brands. There are no large-scale products on the market, and the future market of DSP audio processor is still to be further developed. 

Abstract: Car audio and DSP technology has an inseparable relationship, DSP digital signal processing technology performance of data processing ability is not general processor match.For beginners of audio enthusiasts, how to fully understand and understand the function of DSP processor is the first important.In recent years, be influenced by foreign acoustics refit, domestic car acoustics refit gradually popular rise.In order to enrich their car life and highlight the unique personality, more and more owners began to pay attention to and experience the audio upgrade modification.With the increasing innovation of technology, various digital video and audio technologies are applied more and more in automobiles.DSP digital signal processing technology provides a high performance programmable processor for signal processing applications, which is characterized by flexible applicability, low power consumption, high efficiency and low cost.For the majority of consumers to bring high price products, to solve the urgent needs.

What is a DSP processor?

      DSP (Digital Signal Processing) is a unique microprocessor, which is a device to process a large amount of information with Digital signals.It works by receiving an analog signal and converting it to a 0 or 1 digital signal.Then the digital signal is modified, deleted, and enhanced, and the digital data is interpreted back to analog data or real environment format in other system chips.It is not only programmable, but also capable of running tens of millions of complex instructions per second, which is far more than the general microprocessor. It is an increasingly important computer chip in the digital electronic world.

DSP processor can use the digital signal fixed program to control, using the frequency of the strong or weak to create sound field effect, the auditory environment to create a feeling like in the opera house and other Spaces.Or it can also modify the style of music into Jazz, Pop and other music types.Its powerful data processing capacity and high running speed are the two most praiseworthy features. 

      DSP has several advantages:

1. It is not sensitive to the tolerance of component values and is little affected by external factors such as temperature and environment.

2. Easy to integrate.

3. VLSI can be time multiplexed and shared processor.

4. Convenient to adjust the processor's coefficient to achieve adaptive filtering.

5. It can realize the functions that can not be realized by analog processing: linear phase, multi-sampling rate processing, cascading, easy storage, etc.

6. Can be used for very low frequency signals.

What are the advantages of digital signals over analog signals?

      First of all, let's understand these two terms. What is a digital signal?What is an analog signal?Analog signal refers to the information represented by a continuous change in physical quantity. The amplitude, or frequency, or phase of the signal varies continuously from time to time, such as the current broadcast sound signal, or image signal, etc.Digital signal refers to the value of amplitude is discrete, amplitude representation is limited to a finite number of values.Binary code is a digital signal.Binary code is less affected by noise and easy to be processed by digital circuits, so it has been widely used. 

      Analog communication has two major drawbacks.First of all, confidentiality is poor.Analog communications, especially microwave and wired communications, are vulnerable to eavesdropping.Once the analog signal is received, it is easy to get the content of the communication.Secondly, the anti-interference ability is weak.During the transmission of electrical signals along the road, they will be interfered by the external noise and the internal noise of the communication system. It is difficult to separate the noise and signal mixing, which makes the communication quality decline.The longer the line, the louder the noise.

      The digital signal makes up for the deficiency of the analog signal, and the advantages of digital signal communication are.Firstly, the superiority of digital transmission and exchange.The signal form of digital communication is the same as the signal used by the computer, which is binary code. Therefore, it is easy to network with the computer, and also easy to store, process and exchange the digital signal with the computer. Therefore, the management and maintenance of the communication network can be automated and intelligent.Secondly, it strengthens the confidentiality of communication.Digital communication encryption processing is much easier than analog communication, to voice signal as an example, after the digital transformation of the signal can be simple digital logic operation encryption, decryption processing.Finally, the anti-jamming ability is improved.As a result of the digital signal amplitude for a finite number of discrete values (usually take two amplitude), while in the process of transmission has also been the interference of noise, but when SNR deteriorated to a certain extent, namely in the proper distance using the method of judgment regeneration, regeneration as being without noise and the original sender of digital signal, so it can realize long distance transmission of high quality. 

The difference between car amplifier with DSP processor and ordinary car amplifier

      Car amplifier with DSP processor refers to the use of DSP chip, can be adjusted through the computer, each sound channel parameters (EQ delay frequency points, etc.), can be better managed through the computer Car amplifier.DSP Car amplifier has the functions of other Car amplifier at the same time, it can attenuate the frequency caused by overlapping environment in the car, add the frequency caused by attenuation in the environment, and adjust the distance between each speaker in the car and human ear, etc. DSP Car amplifier it can adjust the physical adjustment of the car can not be the defect.   

      The main features of DSP microprocessor:

1. One multiplication and one addition can be completed in one instruction cycle.

2. The program and the data space are separated so that instructions and data can be accessed simultaneously.

3. The chip has fast RAM, which can usually be accessed in two pieces simultaneously through a separate data bus.

4. Hardware support for loops and jumps with low or no overhead.

5. Fast interrupt handling and hardware I/O support.

6. It has multiple hardware address generators that can operate in a single cycle.

7. Multiple operations can be performed in parallel.

8. Support pipelining operation, so that fingering, decoding and execution operations can be overlapped.

      Compared with the ordinary Car amplifier, it is obviously much better.Ordinary Car amplifier can only adjust: gain, high and low pass, can not be connected with the computer.DSP Car amplifier can be better managed through the computer Car amplifier.DSP Car amplifier has several advantages that ordinary Car amplifier does not have.First of all, the DSP module into the amplifier, save wire cost and wire interference, but also save the installation space in the car.Secondly, the Car amplifier with DSP function is very convenient to do the active frequency division, delay processing, EQ adjustment, so that the complex environment of the car can be improved, so that the sound of the sound more resistant to listen better!

DSP technology application and host

      As technology matures, manufacturers have been able to improve the performance and availability of digital car audio equipment.By operating in sideband and intermediate frequency (IF) signals of automotive entertainment systems, the digital signal processor (DSP) has evolved the automotive radio from a single audio processor into a sophisticated high-tech information and entertainment center.Due to its own characteristics, DSP plays an irreplaceable role in the field of digital signal processing. Digital signal processing of automobile radio is a technology that infiltrates digital media into the vehicle radio.

      This year the market DSP host has become a trend, automotive DSP can provide a higher level of function on a single chip, the vehicle audio source DSP chip implanted in the host, refined the very important frequency division network and delay system.Probably because of the cost, it also simplifies the number of bands in the EQ with Q tuning, and with these DSP features it is not difficult to tune a race-level system.In addition, the DSP system provides an extended listening range for the car radio, allowing users to receive more radio stations over a wider frequency band without the need to constantly adjust the radio for better reception.DSP will make traditional analog AM and FM broadcasts clearer, with better sound quality and less interference. 

The development trend of DSP

      With the application of DSP in the field of communication, digital audiovisual products will be more and more popular, making the related market demand is more and more big, the future DSP market competition will become more and more intense.Although the market for the main application products of DSP is controlled by the big international semiconductor companies, the local manufacturers are actively investing in research and development resources and taking consumer products as a starting point to enter the DSP market.They will gain a place in the DSP market.

　　Digital signal processing (DSP) technology is playing an indispensable role.The development of DSP devices must take into account 3P factors, that is, performance, power consumpTIon and price.In general, with the rapid development of VLSI technology, modern DSP devices keep improving their performance and reducing the power consumption per unit of computation while the price drops significantly.