4.2.3 SWD Lines

The CM4_SWCLK, CM4_SWDIO and CM4_SWO pins are used for SWD Programming and debugging purposes. It is recommended that the CM4_SWCLK and CM4_SWDIO pin be used for the WBZ45 module for SWD as the default configuration (CM4_SWO can be optional).

Keep the trace length between the SWD pins of the WBZ45 module and the SWD header as short as possible. If the SWD connector is expected to experience an ESD event, a series resistor is recommended with the value in the range of a few tens of Ωs, not to exceed 100Ω.

Note: Provide an option for adding an external pull-up on SWDIO.