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avr_string(3avr) avr-libc avr_string(3avr)


avr_string - <string.h>: Strings



#define _FFS(x)

Detailed Description

#include <string.h> 

The string functions perform string operations on NULL terminated strings.


If the strings you are working on resident in program space (flash), you will need to use the string functions described in <avr/pgmspace.h>: Program Space Utilities.

Macro Definition Documentation

#define _FFS(x)

This macro finds the first (least significant) bit set in the input value.

This macro is very similar to the function ffs() except that it evaluates its argument at compile-time, so it should only be applied to compile-time constant expressions where it will reduce to a constant itself. Application of this macro to expressions that are not constant at compile-time is not recommended, and might result in a huge amount of code generated.


The _FFS() macro returns the position of the first (least significant) bit set in the word val, or 0 if no bits are set. The least significant bit is position 1. Only 16 bits of argument are evaluted.


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Fri Nov 24 2023 23:59:10 Version 2.0.0