The ARM® Cortex®-M0+ Debug Acess Port (DAP) enables communication between the core and the device pins during debug.
The Debug Access Port enables the following:
- Halting, resuming, and single stepping of program execution
- Access to processor core registers and special registers
- On-the-fly memory access
- Data watchpoints
- HW/SW breakpoints
- PC sampling for basic profiling
The Data Watchpoint Unit (DWT) is a debug unit that provides up to 2 watchpoints for data tracing and system profiling (CPU statistics, PC sampler).
The Breakpoint Unit (BPU) allows up to 4 Hardware breakpoints to generate debug events
The Micro Trace Buffer (MTB) provides a simple instruction trace. It uses a small portion of SRAM for the trace buffer.
The Serial Wire Debug (SWD) port consists of 3 pins.
Unlike the other SAM micros, the SAM D, SAM L, and SAM C micros (Cortex-M0+ based) do not implement the JTAG interface. It is SWD only.