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

You could write the constant as the result of a calculation (16*1000*1000 for your example). Even better, you could define another macro, MHZ(x), and define your constant as MHZ(16), which would make the code a little bit more self-documenting - at the expense of creating name-space collision probability.

Answer 2

You can use scientific notation:

#define F_CPU 1.6e+007

Or:

#define K 1000

#define F_CPU (1.6*K*K)