AK4629 Datasheet, PDF (25/46 Pages) Asahi Kasei Microsystems – High Performance Multi-channel Audio CODEC

[AK4629]
■ Soft mute operation
Soft mute operation is performed at digital domain. When the SMUTE pin changes to “H”, the output signal is attenuated
by -∞ during ATT_DATA×ATT transition time (Table 13) from the current ATT level. When the SMUTE pin returns to
“L”, 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 -∞, 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
ATT Level
(1)
Attenuation
(1)
(3)
-∞
GD
GD
(2)
AOUT
DZF1,2
(4)
8192/fs
Notes:
(1) ATT_DATA×ATT transition time (Table 13). For example, in Normal Speed Mode, this time is 1792LRCK cycles
(1792/fs) at ATT_DATA=00H. ATT transition of the soft-mute is from 00H to 7FH
(2) The analog output corresponding to the digital input has group delay. (GD)
(3) If the soft mute is cancelled before attenuating to -∞, the attenuation is discontinued and returned to ATT level by
the same cycle.
(4) When the input data at all the channels of the group are continuously zeros for 8192 LRCK cycles, the DZF pin of
each channel becomes “H”. The DZF pin immediately returns to “L” if the input data of either channel of the group
are not zero.
Figure 15. Soft mute and zero detection
■ System Reset
The AK4629 should be reset once by bringing the PDN pin = “L” upon power-up. The AK4629 is powered up and the
internal timing starts clocking by LRCK “↑” after exiting reset and power down state by MCLK. The AK4629 is in the
power-down mode until MCLK and LRCK are input.
MS1277-E-02
- 25 -
2012/03