According to Joel Huloux, chairman of the board of MIPI Alliance, SoundWire consolidates many of the key attributes available in existing mobile and PC-industry audio interfaces and introduces a comprehensive interface and scalable architecture that can be used to transport audio and control data for audio peripherals.
He said companies can apply the specification as needed to best fit their particular systems integration requirements. More than 25 companies from across the audio technology ecosystem—including audio peripheral, electronic design automation and silicon vendors as well as OEMs—took part in developing MIPI SoundWire.
The ratification of MIPI SoundWire by the MIPI Alliance is now underway and scheduled for completion by year-end 2014. Products based on MIPI SoundWire are already in development and IP, silicon components and test tools based on the specification are expected to become commercially available also by year-end 2014, said Huloux.
“MIPI SoundWire is a hardware interface and transport protocol,” he said. “It offers a scalable, low complexity, low power, low latency, 2-pin (clock and data) multidrop bus that allows for the transfer of multiple audio streams and embedded controls/commands.
The specification can be used to add intelligence to audio peripherals, increase the number of peripherals attached to a link and optimize their implementations without compromising product cost, pin count, power consumption, software complexity, or key audio metrics. MIPI SoundWire provides built-in synchronization capabilities and optional multilane extensions and it supports PCM and PDM, multichannel data, isochronous and asynchronous modes.
One of the impacts of SoundWire, saild Huloux is that it can be used to support the use of more advanced amplifiers and microphones. “It can be used to optimize speaker protection, microphone power and performance, noise cancellation, and always-listening audio input,” he said, “and it is expected to enable new use cases not present in previous specifications. I
According to Mohamad El-Hage, vice chair of the MIPI Alliance Low Speed Multipoint Link Working Group, the boundaries between mobile phones, tablets and PCs are converging but until now, standardized audio interfaces have been specific to the individual market segments. “This fragmentation has made it very challenging for firms to scale their product designs for use across segments,” he said. “MIPI SoundWire was developed to provide a common interface to overcome this challenge.”
El-Hage emphasized that MIPI SoundWire was defined by designers for the benefit of designers. “Thanks to the recommendations of engineers involved in hardware and software product integration, the MIPI SoundWire specification embeds built-in self-test and debug capabilities, he said. ”
The MIPI Alliance offers MIPI SoundWire in addition to MIPI SLIMbus, an interface that supports a wide range of digital audio and control solutions needed to transport audio for larger-sized components in mobile terminals, such as the processor and modem.
MIPI SoundWire, said El-Hage, has a lower gate count and can be embedded in small, very-cost-sensitive audio peripherals such as amplifiers and microphones. MIPI SoundWire can coexist with MIPI SLIMbus or non-MIPI interfaces through bridging solutions.