Control Statements

The AARM Assembler provides a number of control statements that permit you to define symbol values, reserve and initialize storage, and control the placement of your code.

These statements should not be confused with processor instructions or with assembler directives. They do not produce executable code and, with the exception of the DB, DD, DW, DBPTR, DSPTR, and DPPTR statements, they have no direct effect on the contents of code memory. These controls change the state of the assembler, define user symbols, and add information to the object file.

Control statements may be divided into the following categories:

Address Control

Statement	Description
ORG	Sets the location counter to a specific offset or address.

Conditional Assembly

Statement	Description
IF	Begins an IF-ELSE-ENDIF block.
ELSEIF	Begins an alternate IF block.
ELSE	Begins an ELSE block.
ENDIF	Terminates an IF block.

Memory Initialization

Statement	Description
DB	Allocates memory for one or more defined byte values.
DCB	Allocates memory for one or more defined byte values.
DCD	Allocates memory for one or more defined 32-bit values.
DCF	Allocates memory for one or more defined 32-bit floating-point values.
DCF64	Allocates memory for one or more defined 64-bit floating-point values.
DCW	Allocates memory for one or more defined 64-bit values.
DD	Allocates memory for one or more defined 32-bit values.
DF	Allocates memory for one or more defined 32-bit floating-point values.
DW	Allocates memory for one or more defined 64-bit values.
SPACE	Allocates and clears memory to zero for a specified number of bytes.

Memory Reservation

Statement	Description
DS	Reserves space for one or more bytes.
DSB	Reserves space for one or more bytes.
DSD	Reserves space for one or more 32-bit double words.
DSW	Reserves space for one or more 16-bit words.

Procedure Declaration

Statement	Description
ENDP	Defines the end of a function.
PROC	Defines the beginning of a function.

Program Linkage

Statement	Description
EXTERN	Defines external symbols.
EXTRN	Defines external symbols.
NAME	Specifies the name of the current module.
PUBLIC	Defines symbols which may be used in other modules.

Segment Control

Statement	Description
AREA	Defines an absolute or relocateable segment.
RSEG	Selects a relocateable segment previously defined.

Symbol Definition

Statement	Description
EQU	Sets a permanent symbol value.
LIT	Assigns a text string to a symbol name.
SET	Sets or resets a symbol value.

Miscellaneous

Statement	Description
__ERROR__	Outputs a user-defined error message.
END	Signals the end of the assembly module.

Control Statements