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You can use the MAP and FIELD directives
to describe data structures. These directives are always used together.
Data structures defined using MAP and FIELD:
are easily maintainable
can be used to describe multiple instances of the same structure
make it easy to access data efficiently.
The MAP directive specifies the base address
of the data structure. See MAP for more information.
The FIELD directive specifies the amount of memory
required for a data item, and can give the data item a label. It
is repeated for each data item in the structure. See FIELD for more information.
No space in memory is allocated when a map is defined. Use
define constant directives (for example, DCD) to allocate
space in memory.
| Copyright © 2003, 2004 ARM Limited. All rights reserved. | ARM DUI 0231B |
| Non-Confidential | |
| PDF version | |
| Home > Writing ARM and Thumb Assembly Language > Describing data structures with MAP and FIELD directives |