AT32F421
Series Reference Manual
2022.11.11
Page 162
Rev 2.02
Figure 13-18 CK & MCK source in master mode
Divided by
(2xI2SDIV[9:0]+I
2SODD)
Divided by 8
Divided by 4
SCLK
MCK
CK
I2SMCLKOE
Divided by
(2xI2SDIV[9:0]+I
2SODD)
Divided by
(2xI2SDIV[9:0]+I
2SODD)
~CHLEN
CHLEN
I2SMCLKOE
1
0
Apart from the above-mentioned configuration, the following table lists the values of I2SDIV and I2SODD
corresponding to some specific frequencies, as well as their respective error for the users to configure
the I2SDIV and I2SODD.
Table 13-1
Audio frequency precision using system clock
SCLK
(MHz)
MCL
K
Target
Fs
(Hz)
16bit
32bit
I2S
DIV
I2S_ODD
RealFs
Error
I2S
DIV
I2S_ODD
RealFs
Error
120
No
192000 10
0
187500
2.34%
10
0
187500
2.34%
120
No
96000
19
1
96153
0.16%
10
0
93750
2.34%
120
No
48000
39
0
48076
0.16%
19
1
48076
0.16%
120
No
44100
42
1
44117
0.04%
21
1
43604
1.12%
120
No
32000
58
1
32051
0.16%
29
1
31779
0.69%
120
No
22050
85
0
22058
0.04%
42
1
22058
0.04%
120
No
16000
117
0
16025
0.16%
58
1
16025
0.16%
120
No
11025
170
0
11029
0.04%
85
0
11029
0.04%
120
No
8000
234
1
7995
0.05%
117 1
8012
0.16%
120
Yes
96000
2
1
93750
2.34%
2
1
937500
2.34%
120
Yes
48000
5
0
46875
2.34%
5
0
46875
2.34%
120
Yes
44100
5
1
42613
3.37%
5
1
42613
3.37%
120
Yes
32000
7
1
31250
2.34%
7
1
31250
2.34%
120
Yes
22050
10
1
22321
1.23%
10
1
22321
1.23%
120
Yes
16000
14
1
16163
1.02%
14
1
16163
1.02%
120
Yes
11025
21
1
10901
1.023% 21
1
10901
1.023%
120
Yes
8000
29
1
7944
0.68%
29
1
7944
0.68%
108
No
192000 9
0
187500.0 2.34%
4
1
187500.0 2.34%
108
No
96000
17
1
96428.57 0.446% 9
0
93750
2.34%
108
No
48000
35
0
48214.29 0.446% 17
11
48214.29 0.446%
108
No
44100
38
1
43831.11
0.61%
19
00
44407.89 0.698%
108
No
32000
52
1
32142.86 0.446% 26
11
31839.62 0.501%
108
No
22050
76
1
22058.82 0.04%
38
10
21915.58 0.609%
108
No
16000
110
1
15995.26 0.029% 55
01
16071.43 0.446%
108
No
11025
153
0
11029.41
0.04%
76
11
11029.41
0.04%
108
No
8000
221
0
7997.63
0.029% 105 10
7997.63
0.029%
108
Yes
96000
2
0
105468.8 9.86%
2
0
105468.8 9.86%
108
Yes
48000
4
1
46875.0
2.34%
4
1
46875.0
2.34%
108
Yes
44100
5
0
42187.5
2.34%
5
0
42187.5
2.34%
108
Yes
32000
6
0
32451.92 1.41%
6
0
32451.92 1.41%