
V PeRiPheRaL MoDuLes 3 (inteRFaCe): i2s inteRFaCe (i2s)
s1C33L17 teChniCaL ManuaL
ePson
V-4-7
V
I2S
i2s_sCK (bit clock) polarity
Use BCLKPOL0 (D6/pI2S_CONTRL_CH0 register) for CH.0 and BCLKPOL1 (D4/pI2S_CONTRL_CH1
register) for CH.1 to select the bit clock polarity.
BCLKPoL0: I2S CH.0 Output Bit Clock Polarity Select Bit in the I2S CH.0 Control (pI2S_CONTRL_CH0)
Register (D6/0x00301C00)
BCLKPoL1: I2S CH.1 Input Bit Clock Polarity Select Bit in the I2S CH.1 Control (pI2S_CONTRL_CH1)
Register (D4/0x00301C04)
I2S_SCKx
I2S_SDO/I2S_SDI
BCLKPOLx = 0 (default)
Data is shifted at the falling edge.
The external DAC/I2S CH.1 samples the data at the rising edge.
I2S_SCKx
I2S_SDO/I2S_SDI
BCLKPOLx = 1
Data is shifted at the rising edge.
The external DAC/I2S CH.1 samples the data at the falling edge.
Figure V.4.4.4 Selecting the Bit Clock Polarity
setting the data format and timing
Data resolution
Use DATRES0 (D9/pI2S_CONTRL_CH0 register) to select either 16 bits or 24 bits as the output data reso-
lution.
Setting DATRES0 to 0 (default) selects 16 bits and setting 1 selects 24 bits.
DatRes0: I2S CH.0 Output Data Resolution Select Bit in the I2S CH.0 Control (pI2S_CONTRL_CH0)
Register (D9/0x00301C00)
Use DATRES1 (D1/pI2S_CONTRL_CH1 register) to select either 16 bits or 24 bits as the input data reso-
lution.
Setting DATRES1 to 0 (default) selects 16 bits and setting 1 selects 24 bits.
DatRes1: I2S CH.1 Input Data Resolution Select Bit in the I2S CH.1 Control (pI2S_CONTRL_CH1)
Register (D1/0x00301C00)
Data format (MsB first/LsB first)
Use DTFORM (D5/ pI2S_CONTRL_CH0 register) to select either MSB first or LSB first as the data output
direction.
Setting DTFORM to 0 (default) selects MSB first and setting 1 selects LSB first.
DtFoRM: I2S CH.0 Output Data Format Select Bit in the I2S CH.0 Control (pI2S_CONTRL_CH0)
Register (D5/0x00301C00)
I2S_WS0
I2S_SCK0
I2S_SDO0
DTFORM = 0 (default)
I2S_WS0
I2S_SCK0
I2S_SDO0
DTFORM = 1
D0
D23
D2
D1
D0
D23 D22
D2
D1
D22
D0
D23
D0
D21 D22 D23
D0
D1
D21 D22
D1
D23
Figure V.4.4.5 Selecting Output Data Format