How the following code working?

[Junde]

I am reading the document about touchGFX, there is some code I can't understand(but no impact for learning touchGFX, just curiosity)

So, how this code can check the MCU speed?​

The document link at here(Page22): https://sw-center-st-com.s3-eu-west-1.amazonaws.com/touchgfx/doc/presentation/board-bring-up-introduction/board-bring-up-introduction-speakernotes.pdf

[KnarfB]

line 109 time holds the difference between end and start time in milliseconds.

[Junde]

@KnarfB​ Thanks for your reply. I know the time holds the milliseconds time, but I don't know how long shoud the while loop need? So, I mean how I can judge the time value is matching with the clock? Have a goog day.