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DATA.B (Reserve Initialized Memory)

The DATA.B directive is used to reserve memory and initialize the reserved

memory to specific values.

See also RES (Reserve Uninitialized Memory).

Syntax:

The DATA.B directive requires an expression, or a list of expressions separated

by commas. A label is optional.

DATA.B expr

DATA.B expr, expr, ...

label DATA.B expr

label DATA.B expr, expr, ...

The assembler reserves a block of data with a size, in bytes, that matches the

number of expressions in the argument, and initializes each byte to the

corresponding expression's value.

The expr expression can have one of the following forms:

• A numeric expression with a value in the range 0..255. Each number,

which can be a constant of a symbolic expression resolved by the linker,

represents one byte of initialized data. For example:

DATA.B h’12, h’34, h’56

• A double-quoted string argument that represents a number of bytes equal

to the number of characters in the string (there is no zero termination

byte). Each character represents one initialized data byte. Because a

string has no implicit termination byte, a single character string in a

DATA.B directive is the same as an ASCII character constant. For

example:

DATA.B “The quick brown fox”

• A pointer expression consists of the PTR keyword followed by an

expression. For example:

DATA.B PTR expr

The expr expression is interpreted as a two-byte constant, and can have

values in the range 0..65535. The expression is a general expression, and

can be any combination of relocatable symbols, imported or exported

symbols, and any applicable operations defined for expressions.

Examples:

The following example defines a look-up table of three constant bytes:

SEG CODE

ORG

APEXP %lookupTable

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Echelon Neuron Bedienungsanleitung Seite 145