4.4: Data Section

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The initialized data must be declared in the "section .data" section. There must be a space after the word 'section'. All initialized variables and constants are placed in this section. Variable names must start with a letter, followed by letters or numbers, including some special characters (such as the underscore, "_"). Variable definitions must include the name, the data type, and the initial value for the variable.

The general format is:

<variableName>         <dataType>         <initialValue>

Refer to the following sections for a series of examples using various data types. The supported data types are as follows:

Declaration
db	8-bit variable(s)
dw	16-bit variable(s)
dd	32-bit variable(s)
dq	64-bit variable(s)
ddq	128-bit variable(s) \(\to\) integer
dt	128-bit variable(s) \(\to\) float

These are the primary assembler directives for initialized data declarations. Other directives are referenced in different sections.

Initialized arrays are defined with comma separated values.

Some simple examples include:

bVar     db    10                 ; byte variable
cVar     db    "H"                ; single character
strng    db    "Hello World       ; string
wVar     dw    5000               ; 16-bit variable
dVar     dd    50000              ; 32-bit variable
arr      dd    100, 200, 300      ; 3 element array
flt1     dd    3.14159            ; 32-bit float
qVar     dq    1000000000         ; 64-bit variable

The value specified must be able to fit in the specified data type. For example, if the value of a byte sized variables is defined as 500, it would generate an assembler error.