I 2 S Master Mode; Table 164. Audio-Frequency Precision Using Standard 8 Mhz Hse - STMicroelectronics RM0365 Reference Manual

RM0365
When the master clock is generated (MCKOE in the SPIx_I2SPR register is set):
f = I2SxCLK / [(16*2)*((2*I2SDIV)+ODD)*8)] when the channel frame is 16-bit wide
S
f = I2SxCLK / [(32*2)*((2*I2SDIV)+ODD)*4)] when the channel frame is 32-bit wide
S
When the master clock is disabled (MCKOE bit cleared):
f = I2SxCLK / [(16*2)*((2*I2SDIV)+ODD))] when the channel frame is 16-bit wide
S
f = I2SxCLK / [(32*2)*((2*I2SDIV)+ODD))] when the channel frame is 32-bit wide
S
Table 164
Note: Other configurations are possible that allow optimum clock precision.

Table 164. Audio-frequency precision using standard 8 MHz HSE

I2S_DIV
SYSCLK
(MHz)
16-bit 32-bit
72 11
72 23
72 25
72 35
72 51
72 70
72 102
72 140
72 3
72 3
72 9
72 6
72 9
72 13
72 17
1. This table gives only example values for different clock configurations. Other configurations allowing optimum clock
precision are possible.
2
30.7.6 I S master mode
2
The I S can be configured as follows:
•
In master mode for transmission or reception (half-duplex mode using I2Sx)
•
In master mode transmission and reception (full-duplex mode using I2Sx and
I2Sx_ext).
This means that the serial clock is generated on the CK pin as well as the Word Select
signal WS. Master clock (MCK) may be output or not, controlled by the MCKOE bit in the
SPIx_I2SPR register.
provides example precision values for different clock configurations.
I2S_ODD
16-bit 32-bit
6 1 0
11 1 1
13 1 0
17 0 1
25 0 1
35 1 0
51 0 0
70 1 1
3 0 0
3 0 0
9 0 0
6 1 1
9 0 0
13 0 0
17 1 1
DocID025202 Rev 7
Serial peripheral interface / inter-IC sound (SPI/I2S)
Target f
S
MCLK
(Hz)
16-bit
No 96000 97826.09
No 48000 47872.34
No 44100 44117.65
No 32000 32142.86
No 22050 22058.82
No 16000 15675.75
No 11025 11029.41
No 8000 8007.11
Yes 48000 46875
Yes 44100 46875
Yes 32000 31250
Yes 22050 21634.61
Yes 16000 15625
Yes 11025 10817.30
Yes 8000 8035.71
(1)
Real f (KHz)
S
32-bit 16-bit
93750 1.90%
48913.04 0.27%
43269.23 0.04%
32142.86 0.44%
22058.82 0.04%
16071.43 0.27%
11029.41 0.04%
7978.72 0.09%
46875 2.34%
46875 6.29%
31250 2.34%
21634.61 1.88%
15625 2.34%
10817.30 1.88%
8035.71 0.45%
Error
32-bit
2.34%
1.90%
1.88%
0.44%
0.04%
0.45%
0.04%
0.27%
2.34%
6.29%
2.34%
1.88%
2.34%
1.88%
0.45%
940/1080
959