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CAVR-4

Descriptions of pragma directives

Reference Guide

#pragma segment

#pragma segment="segment" [memattr] [align]

The 

#pragma

 

segment

 directive declares a segment name that can be used by the 

intrinsic functions 

_ _segment_begin

 and 

_ _segment_end

. All segment declarations 

for a specific segment must have the same memory type attribute and alignment.

The optional memory attribute 

 will be used in the return type of the intrinsic 

function. The optional parameter 

 can be specified to align the segment part. The 

value must be a constant integer expression to the power of two.

#pragma segment="MYSEG" _ _huge 4

See also __segment_begin, page 241.

For more information about segments and segment parts, see the chapter Placing code 
and data.

#pragma type_attribute

#pragma type_attribute=keyword

The 

#pragma

 

type_attribute

 directive can be used for specifying IAR-specific type 

attributes, which are not part of the ISO/ANSI C language standard. Note however, that 
a given type attribute may not be applicable to all kind of objects. For a list of all 
supported type attributes, see Type and object attributes, page 144.

The 

#pragma

 

type_attribute

 directive affects the declaration of the identifier, the 

next variable, or the next function that follows immediately after the pragma directive.

In the following example, even though IAR-specific type attributes are used, the 
application can still be compiled by a different compiler. First, a 

typedef

 is declared; 

a 

char

 object with the memory attribute 

_ _near

 is defined as 

MyCharInNear

. Then a 

pointer is declared; the pointer is located in far memory and it points to a 

char

 object 

that is located in near memory.

#pragma type_attribute=_ _near

typedef char MyCharInNear;

#pragma type_attribute=_ _far

MyCharInNear * ptr;

The following declarations, which use extended keywords, are equivalent. See the 
chapterExtended keywords for more details.

char _ _near * _ _far ptr;