ARM Software Development Toolkit Reference Guide 5.8.21. DCD or & directive

5.8.21. DCD or & directive

The DCD directive allocates one or more words of memory, aligned on 4-byte boundaries, and defines the initial runtime contents of the memory. & is a synonym for DCD.

Syntax

The syntax of DCD is:

{label} DCD expression{,expression}

where:

expression

is either:

A numeric expression. See Numeric expressions.
A program-relative expression.

Usage

You must use the DATA directive if you use DCD to define labeled data within Thumb code. Refer to DATA directive for more information.

DCD inserts up to 3 bytes of padding before the first defined word, if necessary, to achieve 4-byte alignment. Use DCDU if you do not require alignment.

Example

data1		DCD		1,5,20				; Defines 3 words containing
								; decimal values 1, 5, and 20
data2		DCD		mem06				; Defines 1 word containing the
								; address of the label mem06
data3		DCD		glb + 4				; Defines 1 word containing
								; 4 + the value of glb

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