Advanced Configuration and Power Interface Specification

ACPI Source Language (ASL)Reference
)
Decode,
MinType,
MaxType,
TypeSpecificFlags,
AddressGranularity,
MinAddress,
MaxAddress,
AddressTranslation,
AddressLength,
ResourceSourceIndex,
ResourceSource,
DescriptorName
// Nothing (PosDecode) | DecodeKeyword (_DEC)
// Nothing (MinNotFixed) | MinKeyword (_MIF)
// Nothing (MaxNotFixed) | MaxKeyword (_MAF)
// ByteConstExpr (_TSF)
// WordConstExpr (_GRA)
// WordConstExpr (_MIN)
// WordConstExpr (_MAX)
// WordConstExpr (_TRA)
// WordConstExpr (_LEN)
// Nothing | ByteConstExpr
// Nothing | StringData
// Nothing | NameString
19.3 ASL Concepts
This reference section is for developers who are writing ASL code while developing definition
blocks for platforms.
19.3.1 ASL Names
This section describes how to encode object names using ASL.
The following table lists the characters legal in any position in an ASL object name. ASL names are
not case-sensitive and will be converted to upper case.
Table 19-351 Named Object Reference Encodings
Value Description Title
0x41-0x5A, 0x5F, 0x61-0x7A Lead character of name
LeadNameChar
(‘A’–‘Z’, ‘_’ , ‘a’–‘z’)
0x30-0x39, 0x41-0x5A, 0x5F, 0x61-
0x7A
Non-lead (trailing) character of name (‘A’–
‘Z’, ‘_’, ‘a’–‘z’, ‘0’–‘9’)
NameChar
The following table lists the name modifiers that can be prefixed to an ASL name.
Table 19-352 Definition Block Name Modifier Encodings
Value Description NamePrefix := Followed by …
0x5C Namespace root (‘\’) RootPrefix Name
0x5E Parent namespace (‘^’) ParentPrefix ParentPrefix or Name
19.3.1.1 _T_x Reserved Object Names
The ACPI specification reserves object names with the prefix _T_ for internal use by the ASL
compiler. The ASL compiler may, for example, use these objects to store temporary values when
implementing translation of complicated control structures into AML. The ASL compiler must
declare _T_x objects normally (using Name) and must not define them more than once within the
same scope.
Version 6.0 785