Asahi KASEI AK4588, Manual, Page: 45 / 76

ASAHI KASEI [AK4589]
MS0339-E-00 2004/09
- 45 -
Sampling Frequency and Pre-emphasis Detection
The AK4589 has two methods for detecting the sampling frequency as follows.
1. Clock comparison between recovered clock and X’tal oscillator
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 X’tal Frequency
0 0 11.2896MHz
0 1 12.288MHz
1 0 24.576MHz
1 1 (Use channel status)
Default
Table 19. Reference X’tal frequency
Except XTL1,0= “1,1” XTL1,0= “1,1”
Register output fs
Consumer
mode
(Note 2)
Professional mode
FS3 FS2 FS1 FS0
Clock comparison
(Note 1)
Byte3
Bit3,2,1,0
Byte0
Bit7,6
Byte4
Bit6,5,4,3
0 0 0 0 44.1kHz 44.1kHz 0 0 0 0 0 1 0 0 0 0
0 0 0 1 Reserved Reserved 0 0 0 1 (Others)
0 0 1 0 48kHz 48kHz 0 0 1 0 1 0 0 0 0 0
0 0 1 1 32kHz 32kHz 0 0 1 1 1 1 0 0 0 0
1 0 0 0 88.2kHz 88.2kHz ( 1 0 0 0 ) 0 0 1 0 1 0
1 0 1 0 96kHz 96kHz ( 1 0 1 0 ) 0 0 0 0 1 0
1 1 0 0 176.4kHz 176.4kHz ( 1 1 0 0 ) 0 0 1 0 1 1
1 1 1 0 192kHz 192kHz ( 1 1 1 0 ) 0 0 0 0 1 1
Note1: At least
±
3% range is identified as the value in the Table 20. 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 20. fs Information
The pre-emphasis information is detected and reported on PEM bit. These information are 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
0 OFF
≠
0X100
1 ON 0X100
Table 21. PEM in Consumer Mode
PEM Pre-emphasis
Byte 0
Bits 2-4
0 OFF
≠
110
1 ON 110
Table 22. PEM in Professional Mode