15
Instruction Set Reference
15 – 11
Table 15.4 gives a summary list of all MAC instructions. In this list,
condition stands for all the possible conditions that can be tested and xop
and yop stand for the registers that can be specified as input for the MAC.
A complete list of the permissible xops and yops is given in the reference
page for each instruction.
MAC Instructions
[IF condition]
MR
=
xop *
yop
(
SS
);
MF
xop
SU
US
UU
RND
[IF condition]
MR
=
MR + xop * yop
(
SS
);
MF
xop
SU
US
UU
RND
[IF condition]
MR
=
MR – xop * yop
(
SS
);
MF
xop
SU
US
UU
RND
[IF condition]
MR
=
0;
MF
[IF condition]
MR
=
MR [( RND )];
MF
IF MV SAT MR ;
Table 15.4 MAC Instructions
15.5.3
Shifter Group
Here is an example of one of the Shifter instructions, Normalize:
IF NOT CE SR= SR OR NORM SI (HI);
The conditional expression, IF NOT CE, tests the “not counter expired”
condition. If the condition is false, a NOP is executed. The destination of
all shifting operations is the Shifter Result register, SR. (The destination of
exponent detection instructions is SE or SB, as shown below.) In this
example, SI, the Shifter Input register, is the operand. The amount and
direction of the shift is controlled by the signed value in the SE register in
all shift operations except an immediate shift. Positive values cause left
shifts; negative values cause right shifts.