Audio Solutions

ARM enables audio product manufacturers to meet the demands of audio clarity, more storage capacity, ease of use, portability and longer battery life through an ideal combination of leading processors and an audio software ecosystem. ARM enables possibilities ranging from simple speech playback to high end surround sound. The excellent combination of processor and software offerings is driving a widespread shift in the audio market from specialized DSPs to ARM processors.

The software offerings through the ARM Connected Community include products like codecs for standards including MP3 and GSM AMR, enhancements such as echo cancellation and reverberation, post processing solutions for mixing and filtering, 3D positional audio, digital radio products and many others. For details of ARM based audio software availability, please refer to the Audio Software page in the Multimedia section of the ARM Connected Community.

Choosing the right processor

Choosing the right software

Embedded audio design can be broadly categorized into three use case scenarios, each one is well served by ARM's diverse processor portfolio:

Scenario 1 - Dedicated audio subsytem

All audio functionality could be handled by a dedicated design subsystem. Depending upon requirements, this approach has several advantages including uninterrupted audio, efficient power management and ease of design. For example, a system could have two ARM9 processors, using the main ARM926 platform for filtering, copy protection, stream analysis and post processing and a low-cost, low power implementation of a dedicated ARM968 for basic audio playback functionality.

Scenario 2 - Just one main processor

Another design choice could be to run all audio on the main processor, using its capabilities over and above that required for the main functionality. The range of applications, workload and required bandwidth could also be very varied. Microcontroller parts based on the Cortex-M3 processor, available in the market today, can comfortably perform a wealth of control functionality combined with MP3 decode. At the same time, if the requirement is to handle application processing for a high end mobile phone and also enable significant audio enhancements and post-processing, then a Cortex-A series processor would be more appropriate.

Scenario 3 - Dynamic sharing of workload

The third choice could be to scale the audio workload between the processors in the system dynamically. This approach has the potential to optimize around the power and performance bottlenecks in the design and split the audio workload across a multicore processor. ARM MPCore technology is ideally suited for this kind of usage scenario where a scaleable multicore processor can dynamically supply the performance required for advanced scenarios, while maximizing power efficiency during simple audio playback.

In all the above stated scenarios, the various benefits ARM processors bring to embedded audio are outlined below.

Processor	Major benefits for audio design
Cortex-A Series	Top end performance and NEON SIMD engine for high-end multimedia
Cortex-R Series	Best in class real time performance for high efficiency
Cortex-M Series	Efficient audio processing for MCU class devices
ARM11 Family	All ARM9E family benefits + additional performance of SIMD
ARM9 Family	Excellent performance with DSP instructions and single-cycle MAC
ARM7 Family	Low-cost silicon choice for many audio applications

The choice of which audio software to run on an ARM processor is an important decision and the availability of products for the intended audio standard is paramount to ensuring a quick time to market. There are many software partners in the ARM Connected Community offering leading codec products which enable fast design cycles for audio applications, on ARM processors.

The most important criteria in choosing a codec for your application is performance. Different factors can have major ramifications on your system design and memory requirements, which in turn can have a significant impact on the total system cost. The audio software partners in the ARM Connected Community offer products with compelling performance and very low memory requirements.

For details of ARM based audio software availability, please refer to the Audio Software page in the Multimedia section of the ARM Connected Community.