STM32F042K6U6: Using PF11 as GPIO/EXTI Pin & Clarity required on Boot Process

[shashank26]

Dear Team,

As per the datasheet, the PF11 is used for BOOT0. However STM32CubeIDE doesn't specify the PF11 as BOOT Pin in the IOC File. 

Also, The Reference Manual doesn't specify usage of the BOOT Pin (Grey marked area).

Please provide clarity on the following,

1) How does the boot up process occur in this MCU? Does it require a resistor pull down at PF11 Pin for normal boot to main flash memory?

2) If not, can PF11 be used as normal GPIO/EXTI Pin?

Awaiting your response.

Regards,

Shashank

[TDK]

1) Per the table in the RM, if BOOT_SEL=1, then BOOT0 pin must be tied low to boot into flash. If BOOT_SEL=0, BOOT0 pin state doesn't matter.

2) The BOOT0 pin state is only sampled at startup. After that, you can configure it as GPIO and use how you want.

> Also, The Reference Manual doesn't specify usage of the BOOT Pin (Grey marked area).

What is unclear about the table? A "x" means "don't care" which means the pin can be in any state.