Watchdogs are used to reboot out of the bootloader. There is a
scratch register for user watchdogs. So use sdk functions to better
distinguish these.
Related to #7346
The RP2040 is new microcontroller from Raspberry Pi that features
two Cortex M0s and eight PIO state machines that are good for
crunching lots of data. It has 264k RAM and a built in UF2
bootloader too.
Datasheet: https://pico.raspberrypi.org/files/rp2040_datasheet.pdf
Scott Shawcroft
Jeff Epler
Robert Pafford