
Writing Assembly Language Programs
Source Statement Format
MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
For More Information On This Product,
Go to: www.freescale.com
2-5
2.4.3
Operand Field
The interpretation of the operand field is dependent on the contents of the operation field.
The operand field, if present, must follow the operation field, and must be preceded by at
least one space or tab. The operand field may contain a symbol, an expression, or a com-
bination of symbols and expressions separated by commas. There should be no inter-
vening whitespace characters separating operand elements.
The operand field of machine instructions is used to specify the addressing mode of the
instruction, as well as the operand of the instruction. The format of the operand field for a
particular instruction is given in Appendix A of the User Manual for the DSP in question
(.e.g.
DSP56000/DSP56001 User’s Manual
). The operand fields of Assembler directives
are described in Chapter 6. The operand fields of macros (Chapter 5) depend on the def-
inition of the macro.
2.4.4
Operation 2 Field
DSP96000 only. The second operation field occurs after the first operand field, and only
in conjunction with an
FMPY
instruction. The field must be preceded by at least one space
or tab. The second operation field may consist only of the instructions
FADD
,
FSUB
, and
FADDSUB
.
2.4.5
Operand 2 Field
DSP96000 only. The interpretation of the second operand field is dependent on the con-
tents of the second operation field. The second operand field, if present, must follow the
second operation field, and must be preceded by at least one space or tab. The operand
field may contain only those register combinations appropriate to the second operation
field.
The operand field of machine instructions is used to specify the addressing mode of the
instruction, as well as the operand of the instruction. The format of the operand field for
each DSP96000 instruction is described in Appendix A of the
DSP96002 User’s Manual
.
2.4.6
Data Transfer Fields
Most opcodes can specify one or more data transfers to occur during the execution of the
instruction. These data transfers are indicated by two addressing mode operands sepa-
rated by a comma, with no embedded blanks. If two data transfers are specified, they
must be separated by one or more blanks or tabs. See the appropriate DSP User’s Man-
ual for a complete discussion of addressing modes that are applicable to data transfer
specifications.
F
Freescale Semiconductor, Inc.
n
.