DocID029088 Rev 3
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UM2036
Hardware layout and configuration
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6.6 Audio
An audio codec WM8994ECS/R with 4 DACs and 2 ADCs inside is connected to SAI
interface of the STM32F779NI to support TDM feature on SAI port. This feature is able to
implement audio recording on digital and analog microphone and audio playback of different
audio streams on headphone and line-out at the same time.
It communicates with the STM32F779NI via I2C1 bus which is shared with LCD, camera
module, and MFX (Multi-Function expander).
The analog microphone on the headset is connected to ADC of WM8994ECS/R through the
audio jack CN28. External speakers can be connected to WM8994ECS/R via the audio jack
CN27.
Two digital microphones (MEMS microphone) MP34DT01TR are available on the
STM32F779I-EVAL evaluation board. They can be connected to either the audio codec or
the DFSDM port of the STM32F779NI by setting
jumpers shown in
. The coupon connectors CN24 and CN25 can be used to support MEMS
microphone evaluation board STEVAL-MKI129V1 after removing SB78 and SB79.
An optical connector CN29 is implemented on the STM32F779I-EVAL to receive external
audio data which is compatible with SPDIF spec.
Table 7. Audio related jumpers
Jumper
Description
JP23
Data signal on digital microphone is connected to audio codec when JP23 is set as
shown to the right (Default setting)
Data signal on digital microphone is connected to DFSDM of STM32F779NI when
JP23 is set as shown to the right (Also need to set JP7 according to this table):
JP24
Clock signal on digital microphone is connected to audio codec when JP24 is set as
shown to the right (Default setting)
Clock signal on digital microphone is connected to DFSDM of STM32F779NI when
JP24 is set as shown to the right