Single chip microcomputer how to calculate the delay time of different crystal oscillator?

SCM C language, how to calculate the delay time of the delayed function by the number of cycles?

First you need to know that an instruction period is a few seconds algorithm is 1/(Crystal frequency divided by 12) then you need to know how the loop actually executes a few instruction cycles

You can use the Keil inline disassembly command to see if your loop is compiled into a machine language after a few instruction cycles so that you know the delay time, of course, you can take the approximate value, such as for (i=0,i<255,i++) {x=2} here x=2 is an instruction cycle and executed 255 times If your crystal is 12MHZ, then you execute an instruction period of 1us 255 times is 0.255ms

22.1184 one instruction 0.5us 1/(23/12)

Single chip microcomputer how to calculate the delay time of different crystal oscillator?