ASAHI KASEI
[AK4367]
Soft Mute
Soft mute operation is performed at digital domain. When the SMUTE bit goes to “1”, the output signal is attenuated by
−∞ during ATT_DATA×ATT transition time (Table 5) from the current ATT level. When 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. If the soft mute is cancelled before attenuating to −∞ 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 bit
ATS bit
(1)
ATS bit
(1)
ATT Level
Attenuation
(3)
-∞
GD
GD
(2)
Analog Output
Figure 14. Soft Mute Function
Notes:
(1) ATT_DATA×ATT transition time (Table 5). For example, this time is 3712LRCK cycles (3712/fs) at ATS bit =
“1” and ATT_DATA = “128”.
(2) The analog output corresponding to the digital input has a group delay, GD.
(3) If the soft mute is cancelled before attenuating to −∞ after starting the operation, the attenuation is discontinued
and returned to ATT level by the same cycle.
MS0247-E-02
2005/10
- 17 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
