TAL Reference Manual

Data Representation
TAL Reference Manual—526371-001
3-7
Address Types
Address Types
TAL supports the following pTAL address types. For further details, see the pTAL
Reference Manual.
pTAL supports 10 address types that control the addresses you store into pointers.
pTAL uses address types to ensure that your program addresses the same relative
data locations on a RISC processor as it does on a CISC processor. Address types are
like data types except that:
•
Address types are used primarily to describe the addresses that you assign to a
pointer, not the data your program is processing.
•
pTAL implicitly determines the address type of a pointer based on how you declare
the pointer. You cannot explicitly declare a pointer’s address type.
•
Only operations that are meaningful for addresses are valid on address types.
•
An address type identifies:
°
The location of the data to which the pointer points.
°
The addressing mode to use when accessing the data.
Address types are summarized in Table 3-5. This table also identifies the target data
that applies to each address when you run pTAL on a CISC processor.
Syntax for Constants
The remaining pages of this section describe the syntax definitions for specifying
constants in your program. You can specify the following kinds of constants:
•
Character string constants (all data types)
•
STRING numeric constants
Table 3-5. Address Types
Data Type Type Target Data on a CISC Processor
BADDR Byte 8-bit bytes in the user data segment
WADDR Word 16-bit words in the user data segment
CBADDR Byte 8-bit bytes in the user code segment
CWADDR Word 16-bit words in the user code segment
SGBADDR Byte 8-bit bytes in system globals
SGWADDR Word 16-bit words in system globals
SGXBADDR Byte 8-bit bytes in system globals
SGXWADDR Word 16-bit words in system globals
EXTADDR Byte Data in an extended segment
PROCADDR N.A. Index of a procedure in the PEP table