CDB4365 datasheet(40/52 Pages) CIRRUS

40 / 52 page

DS670F1

CS4365

Soft Ramp on Zero Crossing

Soft Ramp and Zero Cross Enable dictates that signal-level changes, either by attenuation changes or

muting, will occur in 1/8 dB steps and be implemented on a signal zero crossing. The 1/8 dB level change

will occur after a timeout period between 512 and 1024 sample periods (10.7 ms to 21.3 ms at 48 kHz

sample rate) if the signal does not encounter a zero crossing. The zero cross function is independently

monitored and implemented for each channel.

6.8.2

Soft Volume Ramp-Up after Error (RMP_UP)

Function:

An un-mute will be performed after executing an LRCK/MCLK ratio change or error, and after changing

the Functional Mode.

When set to 1 (default), this unmute is effected, similar to attenuation changes, by the Soft and Zero Cross

bits in the Volume and Mixing Control register.

When set to 0, an immediate unmute is performed in these instances.

Note:

For best results, it is recommended that this feature be used in conjunction with the RMP_DN bit.

6.8.3

Soft Ramp-Down before Filter Mode Change (RMP_DN)

Function:

If either the FILT_SEL or DEM bits are changed the DAC will stop conversion for a period of time to

change its filter values. This bit selects how the data is effected prior to and after the change of the filter

values.

When set to 1 (default), a mute will be performed prior to executing a filter mode change and an un-mute

will be performed after executing the filter mode change. This mute and un-mute are effected, similar to

attenuation changes, by the Soft and Zero Cross bits in the Volume and Mixing Control register.

When set to 0, an immediate mute is performed prior to executing a filter mode change.

Note:

For best results, it is recommended that this feature be used in conjunction with the RMP_UP bit.

6.8.4

PCM Auto-Mute (PAMUTE)

Function:

When set to 1 (default), the Digital-to-Analog converter output will mute following the reception of 8192

consecutive audio samples of static 0 or -1. A single sample of non-static data will release the mute. De-

tection and muting is done independently for each channel. The quiescent voltage on the output will be

retained and the Mute Control pin will go active during the mute period.

When set to 0, this function is disabled.

CDB4365 Datasheet(PDF) 40 Page - Cirrus Logic