•
VREF_DDR used to supply the DDR reference voltage
–
Value: 1.65 V
•
VTT_DDR (LDO3) used to supply the termination resistors of the DDR
–
Value: 1.65 V
•
1V8_Audio (LDO1) used to supply the digital/analog of the audio codec
–
Value: 1.8 V
•
1V2_HDMI (LDO6) used to supply the digital core and analog part of the HDMI transceiver
–
Value: 1.2 V
•
3V3_HDMI (LDO2) used to supply the I/Os of the HDMI transceiver
–
Value: 3.3 V
•
VDD_USB (LDO4) used to supply the USB phy of the STM32MP157x
–
Value: 3.3 V
7.3
Clock sources
7.3.1
LSE clock references
The LSE clock references on the STM32MP157x microprocessor are provided by the external crystal X2:
•
32.768 kHz crystal from NDK : reference NX2012SA
7.3.2
HSE clock references
The HSE clock references on the STM32MP157x microprocessor are provided by the external crystal X6:
•
24 MHz crystal from NDK : reference NX2016SA
7.4
Reset sources
The reset signal of STM32MP157A-DK1 and STM32MP157C-DK2 is active low. The internal PU forces the RST
signal to a high level.
The sources of reset are:
•
Reset button B2 (black button)
•
STPMIC1
•
Embedded ST-LINK/V2.1
•
Arduino
™
connector CN16: pin 3, reset from the Arduino
™
board
•
STM32MP157x
7.5
Boot mode
7.5.1
Description
At startup, the boot source used by the internal bootROM is selected by the Boot pins.
describes the
configurations of the Boot pins.
Table 5.
Boot mode pins
Boot 0
Boot 2
Boot mode
0
0
0
Forced USB boot for flashing.
1
0
0
Not supported.
0
0
1
Reserved.
1
0
1
SD card on SDMMC1.
1. Pin Boot 1 is always tied to "0" by a pull-down resistor.
shows the configurations of the boot-related switch SW1.
UM2534
Clock sources
UM2534
-
Rev 1
page 12/47