This general macro provides a variable value (1-254) for the CHK
field of the data record header. This is done by using the global field
@RCHKA, which is modified each time RCHKA is issued. The GLMOD and
FILKW macros are issued in the macro expansion to allow modification of
@RCHKA.
Format
- label
- A symbolic name can be assigned to the macro statement.
- REG=Rn
- Any application register (other than R0, R14, and R15) that will contain a
variable value to be used as the record code check. This parameter must
be coded.
Entry Requirements
The GLOBZ macro must be issued before you issue RCHKA, and the base
register must still be valid.
Return Conditions
- Control is returned to the next sequential instruction.
- The new value of the record code check will be in the low order byte of
the register. (R15 if parameter is omitted).
- The new value will also be stored in the Global Field @RCHKA+1.
- This macro changes the condition code.
Programming Considerations
- This macro can be executed on any I-stream.
- The register specified as the REG parameter will be used and will contain
the value of the record code check at macro completion. R0, R14, and
R15 must not be used.
- The global field @RCHKA is updated each time this macro is issued.
- RCHKA uses the GLMOD and FILKW macros.
Examples
None.