Motorola DSP96002 - Manual (Page 500)

A - 312 DSP96002 USER’S MANUAL MOTOROLA
A.8 INSTRUCTION ENCODING SUMMARY
The encoding for each instruction is provided with the instruction descriptions in subsection A.7. An instruc-
tion encoding summary is available upon request. Some instructions have legal operation codes but specify
the same destination for two or more simultaneous operations. These instructions are called insane instruc-
tions. An example of an insane instruction is:
MOVE X: ea, D3 Y: ea, D3
Both parallel moves write to the same register (D3) which puts an indeterminate result in D3. These instruc-
tions are flagged as errors by the assembler. However, it is possible to produce an illegal or insane instruc-
tion with the assembler using the DC command.
The following parallel instructions produce insane instructions which will be flagged by the assembler and
should not be used:
X: ea, XXX Y: ea, YYY – for YYY=XXX,
or for all combinations where YYY specifies the same destination as the Data ALU operation,
or for all combinations where XXX specifies the same destination as the Data ALU operation.
—
Xdd
→
XXX Y: ea, YYY – for YYY=XXX, where
–
X is the inversion of the MSB of the XXX field.
or for all combinations where XXX specifies the same destination as the Data ALU operation,
or for all combinations where YYY specifies the same destination as the Data ALU operation.
X: ea, XXX
–
Ydd
→
YYY – for YYY=XXX, where
–
Y is the inversion of the MSB of the YYY field.
or for all combinations where YYY specifies the same destination as the Data ALU operation.
or for all combinations where XXX specifies the same destination as the Data ALU operation.
S: ea, 0DDDDDD – for all combinations where DDDDDD specifies the same destination as the Data ALU
operation.
X: ea, XXX Y:,YYY – for YYY=XXX,
or for all combinations where YYY or XXX specifies the same destination as the Data ALU operation.
L: ea, 10DDDDD – for all combinations where DDDDD specifies the same destination as the Data ALU
operation.
10DDDDD
→
10ddddd (DP) – for all combinations where ddddd specifies the same destination as the
Data ALU operation.
X: ea, X Y:,Y – for Y=X.
S:(Rn+aaaa),0DDDDDD – for all combinations where DDDDDD specifies the same destination as the Data
ALU operation.
X:(Rn+aaaa),XXX Y:,YYY – for YYY=XXX
or for all combinations where YYY or XXX specifies the same destination as the Data ALU operation.
L:(Rn+aaaa),10DDDDD (DP) – for all combinations where DDDDD specifies the same destination as
the Data ALU operation.
X:(Rn+aaaa),X Y:,Y – for Y=X.
0DDDDDD
→
0dddddd – for all combinations where dddddd specifies the same destination as the Data
ALU operation.