12.5.1 I/O Lines
The SWCLK pin is by default assigned to the DSU module to allow debugger probe
detection and to stretch the CPU Reset phase (see Debugger
Probe Detection from Related Links). The
Hot-Plugging feature depends on the GPIO configuration. If the
SWCLK pin function is changed in the port, the Hot-Plugging
feature is not disabled. Hot-Plugging is disabled with the
CFGCON0.HPLUGDIS bit, which is enabled by default. Therefore to
use the SWCLK pin for GPIO functions, it must be disabled by
setting CFGCON0.HPLUGDIS = 1
.