AN4488 Rev 7
25/50
AN4488
Package
49
Figure 11. STM32CubeMX example screen-shot
4.3.1 Handling
unused
pins
All microcontrollers are designed for a variety of applications and often a particular
application does not use 100% of the MCU resources.
To increase EMC performance, unused clocks, counters or I/Os, should not be left free, e.g.
I/Os should be set to “0” or “1”(pull-up or pull-down to the unused I/O pins.) and unused
features should be “frozen” or disabled.
Note:
To reduce leakage it is advisable to configure the I/O as an analog input or to push-pull and
to set it to “0”.
4.4 Boot
mode
selection
4.4.1 Boot
mode
selection
In the STM32F4xxxx, three different boot modes can be selected by means of the
BOOT[1:0] pins as shown in
.