ak4115 AKM Semiconductor, Inc., ak4115 Datasheet - Page 27

• Manufacturer Part Number: ak4115
• Description: High Feature 192khz 24bit Digital Audio Interface Transceiver
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
The pre-emphasis information is detected and reported on PEM bit. This informations is extracted from channel 1 by
default. It can be switched to channel 2 by the CS12 bit in control register.
The AK4115 includes a digital de-emphasis filter (tc=50/15µs). This is an IIR filter corresponds to four sampling
frequencies (32kHz, 44.1kHz and 48kHz). When DEAU bit=“1”, the de-emphasis filter is enabled automatically by the
sampling frequency and pre-emphasis information in the channel status. The AK4115 is in this mode by default. In
parallel control mode, the AK4115 is always placed in this mode and the status bits in channel 1 control the de-emphasis
filter. In serial control mode, DEM0/1 bits control the de-emphasis filter when the DEAU bit is “0”. The internal
de-emphasis filter is bypassed and the recovered data is available without any change if either the pre-emphasis or
de-emphasis mode is OFF. When the PEM bit is “0”, the internal de-emphasis filter is always bypassed.
MS0573-E-00
De-emphasis Filter Control
PEM
1
1
1
1
0
PEM
FS3
1
1
1
1
0
0
0
0
x
Table 17. De-emphasis Auto Control at DEAU bit = “1” (Default)
Table 18. De-emphasis Manual Control at DEAU bit = “0”
DEM1
FS2
PEM
PEM
0
0
1
1
x
0
0
0
x
Table 16. PEM in Professional Mode
0
1
0
1
Table 15. PEM in Consumer Mode
(Others)
Pre-emphasis
Pre-emphasis
DEM0
FS1
OFF
OFF
ON
ON
0
1
1
x
0
1
0
1
x
- 27 -
≠ 0X100
FS0
Bits 3-5
Bits 2-4
0X100
Byte 0
Byte 0
0
0
1
x
≠110
110
44.1kHz
48kHz
32kHz
Mode
OFF
OFF
44.1kHz
48kHz
32kHz
Mode
OFF
OFF
Default
[AK4115]
2006/12