[AK4492]
■ Soft Mute Operation (PCM Mode, DSD Mode, EXDF Mode)
The soft mute operateion is performed at digital domain. When the SMUTE pin goes to “H” or the SMUTE
bit set to “1”, the output signal is attenuated by during ATT_DATA ATT transition (1setting per 16/fs)
time from the current ATT level.
When the SMUTE pin is returned to “L” or the SMUTE bit is returned to “0”, the mute is cancelled and the
output attenuation gradually changes to the ATT level during ATT_DATA ATT transition time(Refer to
Table 32 for ATT). If the soft mute is cancelled before attenuating after starting the operation, the
attenuation is discontinued and returned to ATT level by the same cycle. The soft mute is effective for
changing the signal source without stopping the signal transmission.
SMUTE pin or
SMUTE bit
(1)
(1)
ATT_Level
Attenuation
(3)
-
(2)GD
(2)GD
AOUTL/R
(4)
8192/fs
DZFL/R pin
Figure 52. Soft Mute Function
Note:
(1) ATT_DATA ATT transition time. For example, this time is 4080LRCK cycles at ATT_DATA=255
in PCM Normal Speed Mode.
(2) The analog output corresponding to the digital input has group delay (GD).
(3) If the soft mute is cancelled before attenuating after starting the operation, the attenuation is
discontinued and returned to ATT level by the same cycle.
(4) When the input data for each channel is continuously zeros for 8192 LRCK cycles, the DZF pin for
each channel goes to “H”. The DZF pin immediately returns to “L” if the input data is not zero.
016011073-E-00
2016/12
- 68 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
