Mikroelektronika MIKROE-742 데이터 시트

mikroPascal PRO for AVR uses internal algorithm to distribute objects within mem-
ory. If you need to have a variable or a routine at the specific predefined address,
use the linker directives 

absolute

and 

org

.

Note: You must specify an even address when using the linker directives.

Directive 

absolute

specifies the starting address in RAM for a variable. If the vari-

able spans more than 1 word (16-bit), the higher words will be stored at the consec-
utive locations.

Directive absolute is appended to the declaration of a variable:

var x : word; absolute $32;
// Variable x will occupy 1 word (16 bits) at address $32

y : longint; 

absolute $34;

// Variable y will occupy 2 words at addresses $34 and $36

Be careful when using the absolute directive because you may overlap two vari-
ables by accident. For example:

i : word; 

absolute $42;

// Variable i will occupy 1 word at address $42;

jj : longint; 

absolute $40;

// Variable will occupy 2 words at $40 and $42; thus,

// changing i changes jj at the same time and vice versa

Note: You must specify an even address when using the absolute directive.

Directive org specifies the starting address of a routine in ROM. It is appended to
the declaration of a routine. For example:

procedure proc(par : byte); org $200;
begin
// Procedure will start at address $200;

...
end;

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 5