GD32F403xx User Manual
481
Table 19-8. Audio sampling frequency calculation formulas
MCKOEN
CHLEN
Formula
0
0
I2SCLK / (32 * (DIV * 2 + OF))
0
1
I2SCLK / (64 * (DIV * 2 + OF))
1
0
I2SCLK / (256 * (DIV * 2 + OF))
1
1
I2SCLK / (256 * (DIV * 2 + OF))
19.4.5.
Operation
Operation modes
The operation mode is selected by the I2SOPMOD bits in the SPI_I2SCTL register. There
are f our available operation modes, including master transmission mode, master reception
mode, slave transmission mode, and slave reception mode. The direction of I2S int erface
signals f or each operation mode is shown in the
Table 19-9. Direction of I2S interface
signals for each operation mode.
Table 19-9. Direction of I2S interface signals for each operation mode
Operation mode
I2S_MCK
I2S_CK
I2S_WS
I2S_SD
Master transmission
output or NU(1)
output
output
output
Master reception
output or NU(1)
output
output
input
Slave transmission
input or NU(1)
input
input
output
Slave reception
input or NU(1)
input
input
input
1. NU means the pin is not used by I2S and can be used by other functions.
I2S initialization sequence
I2S initialization sequence is shown as below
Figure 19-52. I2S initialization sequence
.