Emulation headers have 32 data capture resources in total that may be used for runtime watches and breakpoints. For example, if you use a data capture resource for a breakpoint, you will have one less data capture resource for other breakpoints or runtime watches.
Runtime watches and trace are mutually exclusive. Data streaming from the emulation header may be used for either runtime watches or trace. For example, if you want to use trace (Project Properties window, Real ICE™ category, Trace and Profiling option category, “Data Collection Selection” set to trace), you cannot use runtime watches.
Selecting trace in the Project Properties takes precedence over other selections, such as in the Watches window or in any plug-ins.