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ST7 Assembler Linker

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UM0144

A.10

DC.L

A.11

#DEFINE

Purpose:

Define long word(s) in object code.

Format:

DC.L <exp>[,<exp>...]

Description:

This directive forces the long word(s) argument list into the object code at the current

address. The arguments may be composed of complex expressions, which may

even include external labels. If the argument was an expression and had a value

greater than FFFFFFFF then the 32 bits of the expression are used and no errors

are generated. DC.L sends the words with the most significant byte first.

It's generally used for defining data tables. Synonymous with LONG, except that

DC.L stores the long-words in High / Low order.

Example:

See Also:

DC.B, DC.W, BYTE, STRING, WORD, LONG

Purpose:

Define manifest constant.

Format:

#DEFINE <CONSTANT ID> <real characters>

Description:

The benefits of using labels in assembler level programming are obvious and well

known. Sometimes, though, values other than the straight numerics allowed in labels

are used repeatedly in programs and are ideal candidates for special labelling.

The #DEFINE directive allows you to define special labels called 'manifest con-

stants'. These are basically labels that contain strings instead of numeric constants.

During the assembly, wherever a manifest ID is found in the source code, it is

replaced by its real argument before the assembly proceeds. The #DEFINE is not

the definition of a label, so a space must precede the declaration.

The number of defines that the Assembler can manage is limited to 4096. However,

this depends on the number of characters in the statements. Depending on their

length, you may reach this limit sooner.

Example:

UM0144 데이터시트(PDF) 52 Page - STMicroelectronics