NS32FX161-15 Datasheet, PDF (52/102 Pages) National Semiconductor (TI) – Advanced Imaging/Communication Signal Processors

3 0 Functional Description (Continued)
Operation
aligned real X Y
extended Z
for (n40 n ^k LENG n00)
Z 2n 4 (extended) (Z 2n 0 X n low *
Y n low)
Z 2n01 4 (extended) (Z 2n01 0 X n high
* Y n high)
Note When PARAM CLR is set to ‘‘1’’ only multiplication is performed
without addition When PARAM SUB is set to ‘‘1’’ the ‘‘a’’ sign is
replaced by a ‘‘b’’ sign
VCMAD Vector Complex Multiply and Add
The VCMAD instruction multiplies the corresponding ele-
ments of the X and Y complex vectors and adds or sub-
tracts the result to the complex vector Z This result is
placed in the Z output vector
Syntax
EXEC VCMAD
15
10000
Operation
11 10
0
100 1110 0000
complex X Y Z
for (n40 n ^k LENG n00)
Z n 4 (complex) (Z n 0 X n * Y n )
Note When PARAM COJ is set to ‘‘1’’ X n is multiplied by the conjugate
of Y n When PARAM CLR is set to ‘‘1’’ only multiplication is per-
formed without addition When PARAM SUB is set to ‘‘1’’ the ‘‘a’’
sign is replaced by a ‘‘b’’ sign
3 4 5 13 Clipping and Min Max Instructions
VARABS Vector Aligned Real Absolute Value
The VARABS instruction computes the absolute value of
each element in the real vector X and places the result in
the corresponding place in the Y output vector
Syntax
EXEC VARABS
15
10000
Operation
11 10
0
100 0001 1111
aligned real X Z
for (n40 n ^k LENG n00)
Z n low 4 abs (X n low)
Z n high 4 abs (X n high)
Note There is no representation for the absolute value of 0x8000 Whenev-
er an absolute value of 0x8000 is needed OVF SAT is set to ‘‘1’’ and
the maximum positive number 0x7FFF is returned
VARMIN Vector Aligned Real Minimum
The VARMIN instruction compares corresponding elements
of the X and Y real vectors and writes the smaller of the two
in the corresponding place in the Z integer vector
Syntax
EXEC VARMIN
15
10000
Operation
11 10
0
100 0101 1111
aligned real X Y Z
for (n40 n ^k LENG n00)
Z n low 4 min (X n low Y n low)
Z n high 4 min (X n high Y n high)
VARMAX Vector Aligned Real Maximum
The VARMAX instruction compares corresponding ele-
ments of the X and Y real vectors and writes the larger of
the two in the corresponding place in the Z integer vector
Syntax
EXEC VARMAX
15
10000
Operation
11 10
0
100 0110 0110
aligned real X Y Z
for (n40 n ^k LENG n00)
Z n low 4 max (X n low Y n low)
Z n high 4 max (X n high Y n high)
VRFMIN Vector Real Find Minimum
The VRFMIN instruction scans the X real vector and returns
the address of the element with the smallest value The
resulting address is placed in Z 0
Syntax
EXEC VRFMIN
15
11 10
0
10000
100 0110 1101
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