
ASAHI KASEI 
[AK4683] 
MS0427-E-01 
2005/11 
- 46 - 
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 
XTL0 
0 
0 
0 
1 
1 
0 
1 
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 
Consumer 
mode 
(Note 2)
Byte3 
Bit3,2,1,0
0 0 0 0 
0 0 0 1 
0 0 1 0 
0 0 1 1 
( 1 0 0 0 )
( 1 0 1 0 )
( 1 1 0 0 )
( 1 1 1 0 )
Professional mode 
FS3 
FS2 
FS1 
FS0 
Clock comparison 
(Note 1) 
Byte0 
Bit7,6 
0 1 
Byte4 
Bit6,5,4,3
0 0 0 0 
0 
0 
0 
0 
1 
1 
1 
1 
0 
0 
0 
0 
0 
0 
1 
1 
0 
0 
1 
1 
0 
1 
0 
1 
0 
1 
0 
1 
0 
0 
0 
0 
44.1kHz 
Reserved 
48kHz 
32kHz 
88.2kHz 
96kHz 
176.4kHz 
192kHz 
44.1kHz 
Reserved 
48kHz  
32kHz 
88.2kHz 
96kHz 
176.4kHz 
192kHz 
(Others) 
1 0 
1 1 
0 0 
0 0 
0 0 
0 0 
0 0 0 0 
0 0 0 0 
1 0 1 0 
0 0 1 0 
1 0 1 1 
0 0 1 1 
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 
Pre-emphasis
Byte 0 
Bits 3-5 
≠
 0X100
0X100 
0 
1 
OFF 
ON 
Table 49. PEM in Consumer Mode 
PEM 
Pre-emphasis
Byte 0 
Bits 2-4 
≠
110 
110 
0 
1 
OFF 
ON 
Table 50. PEM in Professional Mode