In MIPI Soundwire: Digital Audio Simplified, we mentioned that digital audio formats, including Pulse Code Modulation (PCM) and Pulse Density Modulation (PDM), are target applications for MIPI Soundwire. Later, we discussed Digital Audio Streams and Channels. Here, we will talk about the merits MIPI Soundwire protocol has over other available digital audio interfaces.
For more information on MIPI Soundwire, you can download our whitepaper
Major PC audio and mobile companies have been concerned about the limitations of audio interfaces such as PDM, I2S, I2C, SLIMBus and HDAudio for some time. In 2012, the MIPI Alliance LML working group started working on standardization of the Soundwire Interface. In February 2015, the MIPI board adopted version 1.0 of Soundwire Specification. It has the following benefits over other interface technologies:
1. Soundwire supports double data-rate scheme, which reduces power consumption by 40%.
2. Clock-stop mode is provided to save power during idle periods.
3. Frame rate is adjustable to optimize bandwidth and reduce overhead.
4. It has embedded control and command which eliminates the need of other interfaces such as I2C or SPI.
5. The synchronization process uses dynamic sync pattern, which makes synchronization more robust against false synchronization.
6. The transfer protocol is unified for PCM, PDM and general non-audio data.
7. Commands and data are interleaved which reduces latency and it is good for PDM data.
8. It provides bulk transfer protocol for quick startup of devices with DSP capabilities.
9. It implementation is efficient: a simple slave can be as small as 4k gates.
In the next blog, we will discuss a typical use case of Soundwire interface, and how you can leverage Synopsys VIP for MIPI Soundwire to create a test scenario to quickly validate your Soundwire DUT.
For more information on MIPI Soundwire, you can download our whitepaper.