Atmel CAVR-4 Manual De Usuario

CAVR-4

Basic data types

Reference Guide

 

The compiler supports both all ISO/ANSI C basic data types and some additional types.

The following table gives the size and range of each integer data type:

Signed variables are represented using the two’s complement form.

The 

bool

 data type is supported by default in the C++ language. If you have enabled 

language extensions, the 

bool

 type can also be used in C source code if you include the 

file 

stdbool.h

. This will also enable the boolean values 

false

 and 

true

.

The enum type 

ISO/ANSI C specifies that constants defined using the 

enum

 construction should be 

representable using the type 

int

. The compiler will use the shortest signed or unsigned 

type required to contain the values.

When IAR Systems language extensions are enabled, and in C++, the 

enum

 constants 

and types can also be of the type 

long

 or 

unsigned

 

long

.

bool  

8 bits

0 to 1

1

char  

8 bits

0 to 255

1

signed char 

8 bits

-128 to 127

1

unsigned char 

8 bits

0 to 255

1

signed short

16 bits

-32768 to 32767

1

unsigned short  

16 bits

0 to 65535

1

signed int

16 bits

-32768 to 32767

1

unsigned int  

16 bits

0 to 65535

1

signed long 

32 bits

-2

31

 to 2

31

-1

1

unsigned long  

32 bits

0 to 2

32

-1

1

signed long long

64 bits

-2

63

 to 2

63

-1

1

unsigned long long

64 bits

0 to 2

64

-1

1