Does BOOT0 have an internal resistor? [STM32F303x]

[gbigden]

Posted on April 21, 2015 at 16:38

On startup does the BOOT0 input have a default pull up/down resistor if not connected?

[Tesla DeLorean]

Posted on April 21, 2015 at 22:28

Not sure it's specified, what does the volt-meter say?

You'd really want a way of strapping it high or low.

[pmoore]

Posted on April 22, 2015 at 01:07

Gary:

BOOT0 is not specified as having a pull-up or pull-down, so it likely does not.  Also, the Hardware ''Getting Started'' application notes connecting the BOOT pin(s) to either 0V or Vdd via a resistance, never leaving them floating.  This has lead me to always treat them as a high impedance CMOS input, which should aways be referenced to known high or low logic level.  Some of the ST example boards use a 10K or 22K resistor to ground and allow the BOOT pin(s) to be high via jumper or another device's GPIO pin.  I've run the F303 BOOT0 pin this way from a F407 that reprograms the F303 in my application. -Patrick

[gbigden]

Posted on April 22, 2015 at 12:02

OK - thanks.

I'll tie it low - forgot to connect it on PCB