ARM VERSION 1.2

Assembler Reference

3.5.2 Variables

The value of a variable can be changed as assembly proceeds. Variables are of three

types:

•numeric

•logical

•string.

The type of a variable cannot be changed.

The range of possible values of a numeric variable is the same as the range of possible

values of a numeric constant or numeric expression (see Numeric constants and

Numeric expressions on page 3-20).

The possible values of a logical variable are

{TRUE}

{FALSE}

(see Logical expressions

on page3-23).

The range of possible values of a string variable is the same as the range of values of a

string expression (see String expressions on page3-19).

Use the

GBLA

GBLL

GBLS

LCLA

LCLL

, and

LCLS

directives to declare symbols r epresenting

variables, and assign values to them using the

SETA

SETL

, and

SETS

directives. See:

•GBLA, GBLL, and GBLS on page7-4

•LCLA, LCLL, and LCLS on page 7-6

•SETA, SETL, and SETS on page7-7.

3.5.3 Numeric constants

Numeric constants are 32-bit integers. You can set them using unsigned numbers in the

range 0 to 2 32 – 1, or signed numbers in the range –231 to 231 – 1. However, the

assembler makes no di stinction betwe en –n and 232 – n. Relational operators such as >=

use the unsigned interpretation. This means that 0 > –1 is

{FALSE}

Use the

EQU

directive to define constants (see EQU on page7-57). You cannot change

the value of a numeric constant after you define it.

See also Numeric expressions on page 3-20 and Numeric literals on page3-21.