The debug subsystem (DEBUGSS) interfaces the serial wire debug (SWD) two-wire physical interface to multiple debug functions within the device. Debugging of processor execution and the device state are supported. The DEBUGSS also provides a mailbox system for communicating with software through SWD.
Key features provided by the debug subsystem include:
- Two-wire (SWDIO, SWCLK) debug interface, compatible with both TI and 3rd party debug probes
- On-chip pullup/pulldown resistors for SWDIO and SWCLK, respectively, enabled by default
- Support for disabling SWD functions to use SWD pins as general-purpose input/output pins
- Capability of waking the device from shutdown
mode upon valid SWD activity
- Debug the processor
- Run, halt, and step debug support
- Four hardware breakpoints (BPU)
- Software-configurable peripheral behavior during processor debug
- Ability to free run select peripherals through debug halt
- Ability to halt select peripherals on a debug halt
- Ability to request reset and mode changes to the Power Management Control (PMCTL)
- Debug subsystem mailbox (DSSM) for passing data and control signals between the SWD interface and boot ROM (as well as application software)
- Support for various security features, including software password authenticated debugging