I²S

Inter-Integrated Circuit Sound (I²S, pronounced "eye-squared-ess"[citation needed]) is a serial interface protocol for transmitting two-channel, digital audio as pulse-code modulation (PCM) between integrated circuit (IC) components of an electronic device.

[1] The standard was last revised on February 17, 2022 and updated terms master and slave to controller and target.

[1] This allows the number of bits per frame to be arbitrary, with no negotiation required between transmitter and receiver.

[1] In audio equipment, I²S is sometimes used as an external link between a CD player or digital audio streaming device and an external digital-to-analog converter, as opposed to a purely internal connection within one player box.

[7] Dutch manufacturer Van Medevoort has implemented Q-link in some of its equipment, which transfers I²S over 4 RCA connectors (data, MCK, LRCK, BCK).