2021-11-05 07:39 AM
Hello, peter
Another question, about BOOT, I find that PA14-BOOT0, but if this MCU has 3 BOOT modes, it need 2 IOs to control, but I can't find the second IO, how can I set the BOOT mode? Or to debug, download firmware?
Regards,
Marvin
Solved! Go to Solution.
2021-11-05 07:46 AM
According to the reference manual, there is one pin (BOOT0) along with several option bytes which dictate how it boots up. There is no BOOT1 pin like there is on other devices due to the pin constraints of a small package.
2021-11-05 07:46 AM
According to the reference manual, there is one pin (BOOT0) along with several option bytes which dictate how it boots up. There is no BOOT1 pin like there is on other devices due to the pin constraints of a small package.
2021-11-06 02:17 AM
Well. So how can I set the BOOT bit since it should be set when the the MCU is powered on, it should be controlled by IO, how I can use nBOOT1 bit to control the mode?
2021-11-06 06:27 AM
nBOOT1 is an option bit and is settable via STM32CubeProgrammer. You can also write code to set it on your board. It is written to flash, however, so the new value won't take effect until reset. You cannot set it via a GPIO since there is not a BOOT1 pin.
I would suggest reading the relevant bits of the reference manual to understand how things here work.
2021-11-07 06:13 PM
Hi, TDK
Thanks a lot.
Regards,
Marvin
2021-11-24 01:16 AM
Hi, TDK
What is the default state of Pin19, PA14/PA15/BOOT0, should I add a pull-up or pull-down resistor to give a default state?
Regards,
Marvin
2021-11-24 07:38 AM
Using option bits here seems like the better solution. The reference manual would tell you the default state, which will be the combination of tying PA15, PA14 and BOOT0 together. The latter is floating by default.
2021-11-24 10:30 PM
So I add a 10k pull-up resistor for this pin, because when I set the default state at low, the MCU can not be download.
Am I right?