EFM32WG Datasheet, PDF (467/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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Figure 17.20. USART Left-justified I2S waveform
USn _CLK
USn _CS
(word select)
USn _TX/
MSB
USn _RX
Right channel
LSB
Left channel
MSB
Right channel
A right-justified stream is shown in Figure 17.21 (p. 467) . The left and right justified streams are equal
when the data-size is equal to the word-width.
Figure 17.21. USART Right-justified I2S waveform
USn _CLK
USn _TX/
LSB
USn _RX
Right channel
MSB
Left channel
LSB
Right channel
In mono-mode, the word-select signal pulses at the beginning of each word instead of toggling for each
word. Mono I2S waveform is shown in Figure 17.22 (p. 467) .
Figure 17.22. USART Mono I2S waveform
USn _CLK
USn _CS
(word select)
USn _TX/
MSB
USn _RX
Right channel
LSB
Left channel
MSB
Right channel
17.3.3.6.3 Using I2S Mode
When using the USART in I2S mode, DATABITS in USARTn_FRAME must be set to 8 or 16 data-bits.
8 databits can be used in all modes, and 16 can be used in the modes where the number of bytes in the
I2S word is even. In addition to this, MSBF in USARTn_CTRL should be set, and CLKPOL and CLKPHA
in USARTn_CTRL should be cleared.
The USART does not have separate TX and RX buffers for left and right data, so when using I2S in stereo
mode, the application must keep track of whether the buffers contain left or right data. This can be done
by observing TXBLRIGHT, RXDATAVRIGHT and RXFULLRIGHT in USARTn_STATUS. TXBLRIGHT
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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