The APB slave ports are compliant with the AMBA 3 APB Protocol Specification and can be connected to the Debug Access Port (DAP). This APB slave interface supports 32-bits wide data, stalls, slave-generated aborts, and ten address bits [11:2] mapping 4KB of memory. An extra PADDRDBG31m signal indicates to the CPU the source of access.

Table A.21 shows the external debug interface signals.