Cirrus Logic CS4299 - Manual (Page 18)

CS4299
18
3.3 AC-Link Protocol Violation - Loss of
SYNC
The CS4299 is designed to handle SYNC protocol
violations. The following are situations where the
SYNC protocol has been violated:
• The SYNC signal is not sampled high for exact-
ly 16 BIT_CLK clock cycles at the start of an
audio frame.
• The SYNC signal is not sampled high on the
256th BIT_CLK clock period after the previous
SYNC assertion.
• The SYNC signal goes active high before the
256th BIT_CLK clock period after the previous
SYNC assertion.
Upon loss of synchronization with the controller,
the CS4299 will ‘clear’ the Codec Ready bit in the
serial data input frame until two valid frames are
detected. During this detection period, the CS4299
will ignore all register reads and writes and will
discontinue the transmission of PCM capture data.
In addition, if the LOSM bit in the Misc. Crystal
Control Register (Index 60h) is ‘set’ (default), the
CS4299 will mute all analog outputs. If the LOSM
bit is ‘clear’, the analog outputs will not be muted.
18 DS319PP6
CS4299