TAL Reference Manual

Pointers
TAL Reference Manual—526371-001
9-3
Usage Considerations
Simple Pointer Initializations
The addressing mode and data type of the simple pointer determines the kind of
address the pointer can contain, as described in Table 9-2
.
Furthermore, the kind of expression you can specify for the address depends on the
level at which you declare the pointer:
•
At the global level, use a constant expression. See also Global Standard Pointer
Initializations.
•
At the local or sublocal level, you can use any arithmetic expression.
Global Standard Pointer Initializations
You can initialize global standard pointers by using constant expressions such as:
Table 9-1. Data Accessed by Simple Pointers
Data Type Accessed Data
STRING Byte
INT Word
INT (32) Doubleword
REAL Doubleword
REAL (64) Quadrupleword
FIXED Quadrupleword
Table 9-2. Addresses in Simple Pointers
Addressing
Mode Data Type Kinds of Addresses
Standard STRING 16-bit byte address in the lower 32K-word area
of the user data segment.
Standard Any except STRING 16-bit word address in the user data segment
Extended STRING 32-bit byte address, normally in the automatic
extended data segment.
Extended Any except STRING 32-bit even-byte address, normally in the
automatic extended data segment. (If you
specify an odd-byte address, results are
undefined.)
Expression Meaning
@identifier Accesses address of variable
@identifier ‘<<’1 Converts word address to byte address