AK4683_07 Datasheet, PDF (47/84 Pages) Asahi Kasei Microsystems – Asynchronous Multi-Channel Audio CODEC with DIR/T

[AK4683]
■ Sampling Frequency and Pre-emphasis Detection
The AK4683 has two methods for detecting the sampling frequency as follows.
1. Clock comparison between recovered clock and XTI/MCLK2
2. Sampling frequency information on channel status
Those could be selected by XTL1, 0 bits. And the detected frequency is reported on FS3-0 bits.
XTL1
0
0
1
1
XTL0
0
1
0
1
XTI/MCLK2 Frequency
11.2896MHz
12.288MHz
24.576MHz
(Use channel status)
(default)
Table 47. Reference XTI/MCLK2 frequency
Except XTL1,0= “1,1”
XTL1,0= “1,1”
Register output
fs
FS3 FS2 FS1 FS0
Clock comparison
(Note 1)
Consumer
mode
(Note 2)
Byte3
Bit3,2,1,0
Professional mode
Byte0
Bit7,6
Byte4
Bit6,5,4,3
0
0
0
0
44.1kHz
44.1kHz
0000
01
0000
0
0
0
1
Reserved
Reserved
0001
(Others)
0
0
1
0
48kHz
48kHz
0010
10
0000
0
0
1
1
32kHz
32kHz
0011
11
0000
1
0
0
0
88.2kHz
88.2kHz
(1000)
00
1010
1
0
1
0
96kHz
96kHz
(1010)
00
0010
1
1
0
0 176.4kHz
176.4kHz
(1100)
00
1011
1
1
1
0
192kHz
192kHz
(1110)
00
0011
Note1: At least ±3% range is identified as the value in the Table 48. In case of intermediate frequency of those two,
FS3-0 bits indicate nearer value. When the frequency is much bigger than 192kHz or much smaller than
32kHz, FS3-0 bits may indicate “0001”.
Note2: When consumer mode, Byte3 Bit3-0 are copied to FS3-0 bits.
Table 48. fs Information
The pre-emphasis information is detected and reported on PEM bit. This information is extracted from channel 1 at
default. It can be switched to channel 2 by CS12 bit in control register.
PEM
0
1
Pre-emphasis
OFF
ON
Byte 0
Bits 3-5
≠ 0X100
0X100
Table 49. PEM in Consumer Mode
PEM
0
1
Pre-emphasis
OFF
ON
Byte 0
Bits 2-4
≠110
110
Table 50. PEM in Professional Mode
MS0427-E-02
- 47 -
2007/04