The firmware PWR configuration must be set as follows in function SystemClock_Config in file main.c:
•
If the hardware configuration is Direct SMPS (Default configuration):
HAL_PWREx_ConfigSupply(PWR_DIRECT_SMPS_SUPPLY);
•
If the hardware configuration is LDO:
HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
If a deadlock occurs because of a mismatch between hardware and firmware PWR settings (SMPS/LDO), the
user can recover the board by applying the following procedure:
1.
Power off the board.
2.
Set SW1 (BOOT0) to 1 (system memory). This changes the BOOT0 pin to 1 instead of 0, thus changing the
device boot address to boot address 1 and making the bootloader start in System memory. This avoids
starting firmware in the user Flash with a wrong SMPS/LDO configuration versus the hardware board
configuration.
3.
Power on the board and connect using STM32CubeProgrammer (
4.
Erase the user Flash.
5.
Power off the board and set SW1 to 0.
6.
The board is recovered and can be used normally with matching firmware PWR.
Table 7.
Internal SMPS, LDO and board configuration
Config1
LDO ON
(SMPS OFF)
Config2
SMPS ON
(LDO OFF)
(Default config)
Config3
(SMPS and LDO cascaded)
SMPS ON
LDO ON
SB1
ON
OFF
OFF
SB2
OFF
ON
OFF
SB3
ON
OFF
ON
SB13
ON
ON
ON
SB16
OFF
OFF
OFF
SB18
OFF
OFF
OFF
SB19
ON
OFF
ON
SB20
OFF
ON
OFF
SB21
OFF
ON
ON
L3
OFF
ON
ON
1. The default setting is in bold.
6.3
MCU current-consumption measurement
The JP1 jumper allows the current consumption of STM32H735IGK6U to be measured directly by removing the
jumper and replacing it with an external ammeter. If there is no ammeter, STM32H735IGK6U is not powered.
6.4
Clock source
Three clock sources are available on the STM32H735G-DK board, as described below:
•
X1 25 MHz oscillator for the STM32H735IGK6U HSE system clock and Ethernet PHY
•
X2 32.768 kHz crystal for the STM32H735IGK6U embedded RTC
•
X3 25 MHz oscillator for the STLINK-V3E
UM2679
MCU current-consumption measurement
UM2679
-
Rev 1
page 14/42
