Data Definition Language (DDL) Reference Manual

Definition Attributes
Data Definition Language (DDL) Reference Manual—529431-004
6-62
Specifying TYPE data-type
Bit Maps for Pascal (D-series Systems Only)
The output for a bit map declared as a field definition is INT (bit-length ) or
UNSIGNED (bit-length ). The Pascal compiler allocates the whole 16-bit word for
the bit fields and treats the unused leading bits as bit fillers.
The output for a bit map declared in a group definition or record is
INT (bit-length ) or UNSIGNED (bit-length ) inside a packed record.
The output for a bit filler is a bit field whose name is of the form FILLER_n ; that is, the
output is the same as for other FILLER items. If any item at the same level as the bit
filler has the same generated filler name, then the filler name ends with the next integer
that does not cause the conflict. Do not try to access bit filler data items or reference
the name of a bit filler.
Avoid defining level-89 clauses with the same name in different items. In Pascal, two
distinctive literals cannot have the same name, whether the literals are numeric
constants or are in an enumeration item. When generating output for Pascal, the DDL
compiler does not check for level-89 clauses of the same name.
For a list of Pascal data types that the TYPE data-type clause generates, see
Table C-4, Sample DDL/Pascal Data Translation Table,
on page C-7.
DEF Reused-Bits.
02 Data-Item Type Binary.
02 Bits-Layout-1
Redefines Data-Item.
03 F-11 TYPE BIT 5.
03 F-12 TYPE BIT 6.
03 F-13 TYPE BIT 4.
02 Bits-Layout-2
Redefines Data-Item.
03 F-21 TYPE BIT 4.
03 F-22 TYPE BIT 3.
End.
RECORD REUSEDBITS
INTEGER*2 DATAITEM
RECORD BITSLAYOUT1
FILLER*2
END RECORD
EQUIVALENCE (BITSLAYOUT1,DATAITEM)
RECORD BITSLAYOUT2
FILLER*2
END RECORD
EQUIVALENCE (BITSLAYOUT2,DATAITEM)
Example 6-50. Bit Field Output for FORTRAN (page2of2)
DDL Type FORTRAN Type