[AK4492]
■ Zero Detection (PCM Mode, DSD Mode, EXDF Mode)
The AK4492 has a channel-independent zero detect function. When the input data at each channel is
continuously zeros for 8192 LRCK cycles, the DZF pin of each channel outputs zero detection flag
independently. Polarity of the detection flag of the DZFL/R pin can be selected by DZFB bit. The DZFL/R
pin goes “H” for zero detection when DZFB bit = “0”, the DZFL/R pin goes “L” when DZFB bit = “1”.
When DZFB bit = “0”, the DZFL/R pin immediately returns to “L” if the input data of each channel is not
zero after going to “H”. If the RSTN bit is “0”, the DZF pins of both L and R channels go to “H”. The DZFL/R
pin returns to “L” in 4 ~ 5/fs after the input data of each channel becomes “1” when RSTN bit is set to “1”.
If DZFM bit is set to “1” while DZFB bit = “0”, the DZF pins of both L and R channels go to “H” only when
the input data for both channels are continuously zeros for 8192 LRCK cycles. The zero detect function
can be disabled by setting the DZFE bit. In this case, DZF pins of both channels are always “L”. The zero
detect function is also disabled when Volume Bypass is selected in DSD mode (Table 22).
Table 35. Zero Detect Select.
DZFE
0
DZFB
RSTN
Data
DZF pin
0
1
-
-
0
-
-
-
L
H
H
L
H
L
0
1
not zero
zero detect
-
not zero
zero detect
1
0
1
1
H
L
(-: Do not care)
016011073-E-00
2016/12
- 64 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
