User`s manual

Source Program Coding
4-4
4
Operation Field
Because there is no label field, the operation field may begin in the
first available column. It may also follow one or more spaces.
Entries can consist of one of two categories:
❏ Operation codes which correspond to the MPC60x
instruction set.
❏ Define Constant directive -- WORD is recognized to define a
constant in a word location.
The size of the data field affected by an instruction is determined by
the data size codes. Some instructions and directives can operate on
more than one data size. For these operations, the data size code
must be specified or a default size applicable to that instruction will
be assumed. The size code need not be specified if only one data
size is permitted by the operation. Refer to the PowerPC 603 RISC
Microprocessor User's Manual, the PowerPC 604 RISC Microprocessor
User's Manual, or the PowerPC MPC750 RISC Microprocessor UserÕs
Manual section on Instructions for a definition of allowable size
codes.
The data size code is not permitted, however, when the instruction
or directive does not have a data size attribute.
Operand Field
If present, the operand field follows the operation field and is
separated from the operation field by at least one space. When two
or more operand subfields appear within a statement, they must be
separated by a comma.
Disassembled Source Line
The disassembled source line may not look identical to the source
line entered. The disassembler makes a decision on how it
interprets the numbers used. If the number is an offset from a
register, it is treated as a signed hexadecimal offset. Otherwise, it is
treated as a straight unsigned hexadecimal.