AK4589_1 Datasheet, PDF (45/76 Pages) Asahi Kasei Microsystems – 2/8-Channel Audio CODEC with DIR

ASAHI KASEI
[AK4589]
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
0
0
1
1
XTL0
X’tal Frequency
0
11.2896MHz
1
12.288MHz
0
24.576MHz
1
(Use channel status)
Table 19. Reference X’tal frequency
Default
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 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
MS0339-E-00
- 45 -
2004/09