The References window shows the results of the last Find References operation. The Find References facility is closely related to the Source Navigator in that it indexes your project and searches for references within the active source code regions.
If you have hidden the References window and want to see it again:
You can also find references directly from the text editor's context menu: right-click the item to find and choose Find References. As a convenience, SEGGER Embedded Studio for ARM is configured to also run Find References when you Alt+Right-click in the text editor—see Mouse-click accelerators.
Increasing the number of threads will complete searches faster, but may reduce the responsiveness of SEGGER Embedded Studio for ARM when editing, for example. You should choose a setting that you are comfortable with for your PC. By default, SEGGER Embedded Studio for ARM launches 16 threads to search the project and is a good compromise for a desktop quad-core PC.