When implemented, debug also contains a Debug Access Port (DAP). It comprises:
Serial Wire JTAG Debug Port (SWJ-DP) to interface to a debugger.
The SWJ-DP is a debug port that combines the JTAG-DP and Serial Wire Debug Port (SW-DP). For more information, see SWJ-DP.
An Advanced High-performance Bus Access Port (AHB-AP) interface to enable the SWJ-DP to access the system over an AHB interface.
Figure 9.1 shows the DAP configuration within debug for SWJ-DP.
If your implementation of the DAP does not include both JTAG-DP and SW-DP, you cannot switch between them.