16.7.2.2 Hot Plugging

Hot-Plugging is the detection of a debugger probe when the external reset pin is not asserted. As shown in the following figure, Hot-Plugging is detected when at least 3 TCK/SWCLK pin rising edges are detected while RESET is not asserted. The hot-plugging detector is reset by a power-reset or a an external reset. The module assumes that the TCK/SWCLK function is controlled by the PORT and defaults to the Debug Port (DP) when any reset asserts. Any change to the PORT TCK/SWCLK pad configuration disables the hot-plugging detection immediately until a power-reset or external reset occurs. Therefore no debugger can connect after such configuration. Moreover, for security reasons, Hot-Plugging is not available when DAL.CPU0 equals to 0 or 3. Availability of the Hot-Plugging feature can be read from the Hot-Plugging Enable bit of the Status B register (STATUSB.HPE).

Figure 16-3. Hot-Plugging Detection Timing Diagram