Spotpear Raspberry Pi Pico Expansion Board Raspberry Pi Debug Probe test board USB-to-debug kit

Overview

The firmware is updated in the same way as Raspberry Pi Pico firmware, so it is easy to keep the unit up to date with the latest firmware, or to use custom firmware.

All modern Arm-based microcontrollers, including RP2040, implement Arm’s CoreSight debug architecture. Each processor core, like the Cortex-M0+ used in RP2040, provides an Access Port (AP) which can be used to single step, set breakpoints, observe the values of processor registers, and access memory and peripherals via the processor’s bus interface.
The microcontroller itself provides a Debug Port (DP), which is connected externally to pins on the package, and internally to each AP in the system. RP2040 exposes its DP via a low-pin-count Serial Wire Debug (SWD) port: by talking the SWD protocol over this port, a host computer can control each core’s AP, in order to debug a program running on the core.
A debug probe provides a bridge between USB and the SWD protocol. While not strictly required if the host computer is a Raspberry Pi (you can wire up the target’s SWD port directly to the GPIO header on a Raspberry Pi), it’s much more convenient to connect via USB. And if you’re using a PC or Mac, USB is your only option.