13.3.3. SWO Shared with JTAG-TDO

For minimal pin count, it is possible to overlay JTAG debug and SWO on the same package pin. This approach is only recommended where there is no provision for a conventional trace port, or for use with more complex system-level debug configuration controls.

If this option is chosen, the Instrumentation Trace is not accessible while the debug port is being used in a JTAG configuration. Serial wire debug and SWO can be used together at the same time.

In order to implement this option, the JTAGNSW output from SWJ-DP is used to control the multiplexor. Figure 13.12 shows the SWO shared with JTAG-TDO option.

Figure 13.12. SWO shared with JTAG-TDO

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