Making large constants in C source more readable?

Question

I\'m working on some code for a microprocessor.
It has a few large, critical constants.

#define F_CPU 16000000UL

In this case, this is the C

Answer 1

It might help readability to define the constant as:

#define F_CPU_HZ 16000000UL

That way you know what type of data is in it. In our SW we have a few peripherals which require assorted prescalers to be set, so we have a #defines like this:

#define SYS_CLK_MHZ    (48)
#define SYS_CLK_KHZ    (SYS_CLK_MHZ * 1000)
#define SYS_CLK_HZ     (SYS_CLK_KHZ * 1000)