
[AK4671] 
MS0666-E-00 
2007/10 
- 100 - 
■
 System Clock (PCM I/F) 
A reference clock of PLLBT is selected among the input clocks to SYNCA, BICKA, SYNCB or BICKB pin. The 
required clock to PCM I/F is generated by an internal PLLBT circuit. PLLBT circuit is powered up by PMPCM bit. Input 
frequency is selected by PLLBT3-0 bits (
Table 76
). BCKO2 bit select the output clock frequency of BICKA or BICKB 
pin (
Table 77
). AK4671 does not support master mode for both PCM I/F A and B nor slave mode for both PCM I/F A and 
B. Whether PCM I/F A or B should be set as slave mode. When PMPCM bit is “0”, SYNCA, BICKA, SYNCB and 
BICKB pins are Hi-Z. 
Table 78
 indicates the output data of SDTOA and SDTOB pins in case of PMPCM bit = “0” and 
during lock time in 
Table 76
, respectively. 
Table 79
 indicates the output clock at master mode during lock time in 
Table 
76
. 
R, C at 
VCOCBT pin 
R 
6.8k 
10k 
10k 
10k 
6.8k 
10k 
10k 
10k 
10k 
10k 
Mode 
PLLBT3 
PLLBT2 
PLLBT1 
PLLBT0
Reference Clock
Input Pin 
Frequency
C 
Lock Time
(max) 
(default)
0 
1 
2 
3 
4 
5 
6 
7 
11 
15 
0 
0 
0 
0 
0 
0 
0 
0 
1 
1 
0 
0 
0 
0 
1 
1 
1 
1 
0 
1 
0 
0 
1 
1 
0 
0 
1 
1 
1 
1 
Table 76. PLLBT Reference Clock (N/A: Not available) 
0 
1 
0 
1 
0 
1 
0 
1 
1 
1 
SYNCA 
BICKA 
BICKA 
BICKA 
SYNCB 
BICKB 
BICKB 
BICKB 
BICKA 
BICKB 
N/A 
1fs2 
16fs2 
32fs2 
64fs2 
1fs2 
16fs2 
32fs2 
64fs2 
48fs2 
48fs2 
220n 
4.7n 
4.7n 
4.7n 
220n 
4.7n 
4.7n 
4.7n 
4.7n 
4.7n 
260ms 
40ms 
40ms 
40ms 
260ms 
40ms 
40ms 
40ms 
40ms 
40ms 
Others 
Note 65. Mode 1 is available at only FMTA1 bit = “0”. 
Note 66. Mode 5 is available at only FMTB1 bit = “0”. 
BCKO2 bit
BICKA/BICKB 
Output Frequency 
16fs2 
32fs2 
0 
1 
(default) 
Table 77. BICKA/B Output Frequency 
Mode 
PMPCM bit = “0” 
After PMPCM bit = “0” 
→
 “1” 
& Before SYNCA/SYNCB Input
L 
H 
H 
Table 78. SDTOA, SDTOB pins Output Data 
PMPCM bit = “1” 
During Locktime 
0000H 
11010101b 
11111111b 
16bit Linear 
8bit A-Law 
8bit 
μ
-Law 
L 
L 
L 
Format 
Except for I
2
S 
I
2
S 
SYNCA, SYNCB 
L 
H 
BICKA, BICKB 
L 
L 
Table 79. Output Clock during Lock Time