2017-09-08 03:02 PM
I have two micros communicating over SPI bus, one is a STM32F031 running application code. I can interrogate the STM32F031 for its firmware version and if it is not the correct version I power off its 3.3 volts, raise the boot0 pin and power it back up into bootloader and transfer the correct version firmware using UART from one micro to the other over UART.
For testing purposes I need to know about low voltage reset. What voltage I must drop 3.3 volts to and for how long in order to guarantee a check of check of boot0 and entrance into the bootloader. Are these volts/timings specified, or what would be reasonable?
2017-09-08 04:54 PM
Couldn't you just clamp NRST easier?
2017-09-11 09:34 AM
There is a flex circuit involved with a limited number of conductors connecting the micros so we would prefer to avoid having to connect NRST even though it is the preferred way to generate a reset.
2017-09-11 09:51 AM
Hi!
this is from STM32f031
Rgrds
vf