AES3
Protocol

AES3

Section Title: Protocol
Table Section Text: None

Time slot	Name	Description

0–3	Preamble	A synchronisation preamble (biphase mark code violation) for audio blocks, frames, and subframes.

4–7	Auxiliary sample (optional)	A low-quality auxiliary channel used as specified in the channel status word, notably for producer talkback or recording studio-to-studio communication.

8–27, or 4–27	Audio sample	One sample stored with most significant bit (MSB) last. If the auxiliary sample is used, bits 4–7 are not included.

28	Validity (V)	Unset if the audio data are correct and suitable for D/A conversion. During the presence of defective samples, the receiving equipment may be instructed to mute its output.

29	User data (U)	Forms a serial data stream for each channel (with 1 bit per frame), with a format specified in the channel status word.

30	Channel status (C)	Bits from each frame of an audio block are collated giving a 192-bit channel status word. Its structure depends on whether AES3 or S/PDIF is used.

31	Parity (P)	Even parity bit for detection of errors in data transmission. (I.e. bits 4–31 have an even number of ones.)

Sentence(s)

In the AES3, there is one channel status bit in each frame, making one 192 bit word in each block.

final_sentence: In the AES3, there is one channel status bit in each frame, making one 192 bit word in each block.