how to calculate timing in keil arm c program

There is absolutely no way whatsoever to predict in advance how many machine cycles will be required by any high-level source construct.

This is fundamental to the whole idea of high-level languages!

You can examine or measure the generated machine code after compilation - but you cannot predict it before compilation.

And you cannot guarantee that it will remain the same after subsequent compilations - even if you don't change any compiler settings!

Therefore, if you really need to know, do it in assembler!

There is absolutely no way whatsoever to predict in advance how many machine cycles will be required by any high-level source construct.

This is fundamental to the whole idea of high-level languages!

You can examine or measure the generated machine code after compilation - but you cannot predict it before compilation.

And you cannot guarantee that it will remain the same after subsequent compilations - even if you don't change any compiler settings!

Therefore, if you really need to know, do it in assembler!

See: www.8052.com/.../149030

There is absolutely no way whatsoever to predict in advance how many machine cycles will be required by any high-level source construct.

exept if you being the compiller ;) ;) ;)

In which case, you wouldn't need to ask the question!

;-)