6.6.4
Headphone outputs
The STM32MP157D-DK1 and STM32MP157F-DK2 Discovery kits can drive a stereo headphone. The
STM32MP157x sends the stereo audio channels to the codec via its SAI2 TDM port. The codec converts the
digital audio stream to stereo analog signals. It then boosts them for direct drive of the headphone connected to
the CN10 3.5 mm stereo jack receptacles on the board.
The audio codec is set by an I
2
C bus. The address is a 7 bit address plus one bit for read/write (high for read, low
for write). The AD0 pin, connected to GND, gives the least-significant address bit. The address of the audio codec
is 0b1001010x: 0x94 to write and 0x95 to read.
6.6.5
Audio jack connector
shows the CN10 audio jack connector pinout.
Figure 8.
CN10 audio jack connector pinout
describes the CN10 audio jack connector pinout.
Table 7.
CN10 audio jack connector pinout
Pin
Pin name
Signal name
Codec pin
Function
1
1
MIC_IN
MICIN1
Microphone IN
2
2
GND
GND
GND
3
3
AOUTB
AOUTB
OUT_SPEAKER_RIGHT
4
4
AOUTA
AOUTA
OUT_SPEAKER_LEFT
6.6.6
I/O restriction
SAI2 is shared between the audio codec and the GPIO expansion connector. By default, the audio codec is
available because of solder bridges SB13, SB14, SB15, and SB16.
UM2637
Audio
UM2637
-
Rev 2
page 13/47
