Dear Sandeep,

"lacks side-efect" in simple language means "not doing anything meaningful",

I personally donot prefer such "blocking" functions for delay. It has few drawbacks.
1> It only consumes CPU's time & prevents it from doing other things.
2> Not only that they are inaccurate, but the inaccuracy also changes with...
- a. Oscillator Used
- b. Compiler
- c. Memory allocation & memory module
- d. Sometimes even MCU (6 clock derivative / 2 clock derivative)
3> Requires to change optimisation power of compiler, (the optimisation may be needed in other parts of code)
4> Also accurance of any enabled ISR can elongates it, adding to inaccuracy

Regards,
Mahesh