Both. The header might be something like this:
Code:
#ifndef DELAY_H_
#define DELAY_H_
/* delay.h */
void delay_1ms(int amount);
void delay_10ms(int amount);
void delay_1sec(int amount);
void delay_1min(int amount);
#endif
and the source file might be something like this:
Code:
/* delay.c */
#include "delay.h" /* May not be necessary in this case. */
void delay_1ms(int amount) {}
void delay_10ms(int amount) {}
void delay_1sec(int amount) {}
void delay_1min(int amount) {}
Of course, I would rather have one delay function that delays in multiples of a small quantum instead of multiple delay functions that delay in multiples of different quanta.