[AK4492]
■ DSD Signal Full Scale (FS) Detection
The AK4492 has independent full scale detection function for each channel in DSD mode.
The AK4492 detects full scale signal when the DSDL/R input data is continuously “0” (-FS) or “1” (+FS) for
2048 cycles and the detection flag for corresponding channel (DML or DMR bit) becomes “1”. DML and
DMR bits can be read out at the register address “06H”.
When the AK4492 detects full scale signal while DDM bit = “1”, the analog output is muted according to
Table 38. ATS[2:0] bits control a mute transition time. ATS[2:0] bits and DSDD bit settings are also valid
when the AK4492 returns to normal status from full scale detection status.
The recovery timing from full scale detection status and the operation mode of full scale detection are
controlled by DDM bit, DMC bit and DMRE bit. RSTN bit must be set to “0” when changing DDM bit
setting.
Table 38. DSD Mode and Device Status after Full-Scale Detection (DDM bit= “1”)
DSDD
0
Mode
Analog Output
VCML/R (Mute)
Mute Transition Method
Soft Mute
Normal Path
(default)
Volume
Bypass
1
VCML/R (Mute)
Rapid Mute
Table 39. Recovery Method to Normal Operation Mode from Full Scale Detection Status
DDM
0
DMC
x
DMRE
x
Status After Detection
When full scale is detected, Mute function is disabled.
When full scale is detected, Mute function is enabled.
The AK4492 returns to normal operation automatically by
a normal signal input.
When full scale is detected, Mute function is enabled.
The AK4492 keeps mute mode, even if a normal signal is
input.
When full scale is detected, Mute function is enabled.
The AK4492 returns to normal operation when a normal
signal is input and DMRE bit is set to “1”.
(default)
1
1
1
0
1
1
x
0
1
(Note 53)
(x: Do not care)
Note 53. DMRE bit returns to “0” automatically after the AK4492 returns to normal operation.
016011073-E-00
2016/12
- 66 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
