CS44600
trol changes, by the Soft and Zero Cross bits (SZC[1:0]). This bit does not cause a mute condition to occur.
The MUTE_50/50 bit only defines operation during a normal mute condition.
When MUTE_50/50 is set and a mute condition occurs, PSR will not affect the output of the modulator,
regardless if PSR is enabled. Output noise may be increased in this case if the noise on the high voltage
power supply is greater than the system noise. Therefore, it is recommended that if a noisy power supply
is used in a single-ended half-bridge configuration with PSR enabled, MUTE_50/50 should be disabled
and a normal, modulated mute should be used. This will allow the modulator to use the PSR feedback to
reject power supply noise and improve system performance.
7.7.4
Soft Ramp-Down on Interface Error (SRD_ERR)
Default = 0
0 - Disabled
1 - Enabled
Function:
A mute will be performed upon detection of a timing error on the Digital Audio Interface or if an
SRC_LOCK error has occurred. An SRC_LOCK interrupt is an indication that the sample rate converter
timings have become unstable, or have changed abruptly. Audio data from the SRC is no longer consid-
ered valid and could cause unwanted pops or clicks.
When this feature is enabled, this mute is affected, similar to attenuation changes, by the Soft and Zero
Cross bits (SZC[1:0]). When disabled, an immediate mute is performed on detection of an error.
Note:
For best results, it is recommended that this bit be used in conjunction with the SRU_ERR bit.
7.7.5
Soft Ramp-Up on Recovered Interface Error (SRU_ERR)
Default = 0
0 - Disabled
1 - Enabled
Function:
An un-mute will be performed after a MCLK/LRCK ratio change, recovered DAI timing error, or after the
SRC has gained lock. When this feature is enabled, this un-mute is affected, similar to attenuation chang-
es, by the Soft and Zero Cross bits (SZC[1:0]). When disabled, an immediate un-mute is performed in
these instances.
Note:
For best results, it is recommended that this bit be used in conjunction with the SRD_ERR bit.
7.7.6
Auto-Mute (AMUTE)
Default = 1
0 - Disabled
1 - Enabled
Function:
The PWM converters of the CS44600 will mute the output following the reception of 8192 consecutive
audio samples of static 0 or -1. A single sample of non-static data will release the mute. Detection and
muting is done independently for each channel. The muting function is affected, similar to volume control
changes, by the Soft and Zero Cross bits (SZC[1:0]).
54
DS633F1
CIRRUS [ CIRRUS LOGIC ]
