MIPI Alliance has come up with a new protocol standard for sound interface called SoundWire. SoundWire is a robust, scalable, low complexity, low power, low latency, two-pin (clock and data) multi-drop bus that allows for the transfer of multiple audio streams and embedded control/commands. To understand its specification and design verification needs, it is important to understand basics of digital audio transmission.
Traditionally, sound is recorded and transmitted as analog signals. However analog signal is sensitive to noise: it is difficult to send analog signals over a long distance without introducing significant noise. It is also expensive to transmit high quality analog signals over short distances. The solution to this problem is digitization of analog signals: send it in digital form, and again convert it to analog for sound reproduction. This process involves a number of steps and adds complexity to the system, but it is more reliable and cost effective. If designed properly, the degradation of signal due to digitization can be insignificant.
You can learn more about the common digital audio formats, Pulse Code Modulation (PCM) and Pulse Density Modulation (PDM), which are target applications for MIPI Soundwire, by downloading our whitepaper.