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Using Symbolic Access

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Symbolic access references data through the use of symbolic names declared at the source code level, rather than through addresses and offsets to specific memory locations. This facility allows users to access stored information in a more natural way, leaving the drudgery of translating symbolic names to storage locations up to System Debug.

The chart below summarizes the symbolic functions currently available. These functions allow programmatic access to the information provided by the FT and FV commands.

Each function takes a path specification as one of its parameters. The form of this parameter is the same as that used by the FT and FV commands presented on the previous pages.

Each of these functions are presented in detail (including examples) in chapter 8.

Table 7-1 Symbolic Functions Available

SYMVAL ( virtaddress, pathspec ) returns the value of the data structure specified by pathspec.
SYMLEN ( pathspec, [units] ) returns the length of a data structure in bits or bytes.
SYMADDR ( pathspec, [units] ) returns the bit or byte offset of an element specified by pathspec, relative to the start of the path.
SYMINSET ( virtaddress, pathspec, element ) returns a boolean value of TRUE if the set member element is in the set specified by address and pathspec.
SYMTYPE ( pathspec ) Returns the type of a component described by pathspec.
SYMCONST ( pathspec ) returns the value of the constant specified by pathspec.
Parameters:
virtaddress the address of the actual data. (Required)
pathspec a path specification. (Required)
units specifies whether the return value for SYMLEN and SYMADDR is in bits or bytes. (Optional)
elementa set element. (Required)



Using the Symbolic Formatter

Chapter 8 System Debug Windows