Hardware layout and configuration
UM1668
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DocID025151 Rev 2
2.5 Boot
option
The STM32439I-EVAL evaluation board can boot from:
•
Embedded user Flash
•
System memory with boot loader for ISP
•
Embedded SRAM for debugging
The boot option is configured by setting switch SW1 (BOOT0) and SW2 (BOOT1).
Note:
The RS-232 boot loader mechanism is not supported on the STM32439I-EVAL.
2.6 Audio
An audio codec WM8994ECS/R with 4 DACs and 2 ADCs inside is connected to the SAI
interface of the STM32F439NIH6 to support the TDM feature on the SAI port. This feature
implements 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 STM32F439NIH6 via the I2C1 bus which is shared with the LCD,
camera module, RF-EEPROM, IO expander and CN2 connector.
The analog microphone on the headset is connected to the ADC of WM8994ECS/R.
External speakers can be connected to WM8994ECS/R via audio terminal connector CN24.
There are two digital microphones (MEMs microphone) MP34DT01TR on the STM32439I-
EVAL evaluation board. They can be connected to either audio codec or the I2S port of
STM32F439NIH6 by setting jumpers as shown in
Table 6
.
Table 5. Boot related switches
Switch
Boot description
Switch configuration
SW1 & SW2
STM32439I-EVAL boots from
User Flash
when SW1 is set
as shown to the right. SW2 is not required in this
configuration.
(Default setting)
STM32439I-EVAL boots from
Embedded SRAM
when
SW1 and SW2 are set as shown to the right.
STM32439I-EVAL boots from
System Memory
when SW1
and SW2 are set as shown to the right.
0 <
> 1
SW
0 <
> 1
SW1
SW2
0 <
> 1
SW
SW
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