About Alex_DL8AAU

Alex_DL8AAU · 2019-10-28

Strangely an empty STM32L4R5 will try to boot from system memory and then will try all peripherals turning GPIOs to outputs while trying. Of course this is very dangerous if not taken into account in the design of boards that are to be started with "...

Alex_DL8AAU · 2019-10-30

>> I saw PB9 and PB14 turning to outputs>Are you sure this was during bootloader action?Fairly sure: I erased the chip. Then nothing was connected on PB9 and PB14 but a MOSFET gate and a 100k pull-down. Voltage on the gate was 0V if I keep the CPU in...

Alex_DL8AAU · 2019-10-29

Hi JW,need to check if PA9 actually becomes an output or not (I just assumed it did). I saw PB9 and PB14 turning to outputs - that would be SPI2 and CAN1 boot. But maybe you are right and the reason it gets to try SPI2 and CAN1 means it did not try U...

User statistics

User Activity

Empty STM32L4R5 (with factory default settings) will try peripheral boot through system memory no matter what (bug?). PA9 then becomes output (as USART1_TX). Shall we use a resistor for VBUS?

Re: Empty STM32L4R5 (with factory default settings) will try peripheral boot through system memory no matter what (bug?). PA9 then becomes output (as USART1_TX). Shall we use a resistor for VBUS?

Re: Empty STM32L4R5 (with factory default settings) will try peripheral boot through system memory no matter what (bug?). PA9 then becomes output (as USART1_TX). Shall we use a resistor for VBUS?