How to measure the running time of program in Trace32?

In Trace32 main menu, click Misc. In the pull down menu, select RunTime. The RunTime toll will pop out.
Double the Ref A, set current point as the reference A, click "GO", break at the the point you want to stop. Double the Ref B. The you can get the running time between Ref A and Ref B.
The "laststart" shows the last running time. From the previous break point to current.