NS32FV16 Datasheet, PDF (54/104 Pages) Texas Instruments – Advanced Imaging/Communication Signal Processors

3 0 Functional Description (Continued)
Operation
Operation
real X
integer Z
internal register real tempX
internal register integer tempA
tempX 4 X 0
tempA 4 X 0
for (n41 n ^k LENG n00)
integer Y Z 1
extended temp Z 0
real X
real acc A
A 4 (real acc) ((extended)A)
temp 4 Z 0
if (A ^l temp)
if (X n ^k tempX)
tempX 4 X n
tempA 4 X n
temp 4 (extended) A
Z1 4 X 0
Z 0 4 temp
Z 0 4 tempA
Note The LENG parameter for this operation must be greater than 1
VRFMAX Vector Real Find Maximum
The VRFMAX instruction scans the X real vector and re-
turns the address of the element with maximum value The
resulting address is placed in Z 0
te ^Syntax
EXEC VRFMAX
15
10000
Operation
11 10
0
100 0010 0100
le ^{real X}
integer Z
internal register real tempX
internal register integer tempA
tempX 4 X 0
tempA 4 X 0
o for (n41 n k LENG n00)
if (X n ^l tempX)
s tempX 4 X n
tempA 4 X n
Z 0 4 tempA
b _{Note The LENG parameter for this operation must be greater than 1}
EFMAX Extended Find Maximum
This instruction is not supported by the NS32FX161
The EFMAX instruction implements a single iteration of
O ^{maximum search loop The extended value in the accumula-}
Note The Y vector must hold the following values Y 0 must be 0x7fff Y 1
must be 0x0001 and Y 2 must be 0x4000
3 4 5 14 Special Instructions
ESHL Extended Shift Left
This instruction is not supported by the NS32FX161
The ESHL instruction performs a shift-left operation on ex-
tended-precision data in the accumulator and stores the
more significant half of the result as a real value into the first
element of the real Z vector
Syntax
EXEC ESHL
15
10000
Operation
11 10
0
101 0110 0100
real acc A
A 4 (real acc) ((extended)A)
if (LENG ^l 1) for (n41 n^kLENG n00)
A4A0A
Z 0 4 (real) A
Note The LENG parameter for this operation must be greater than 0 When
LENG equals 1 only the real part of the accumulator is updated
When LENG is greater than 1 both the real and the imaginary parts of
the accumulator are updated to the same value
VCPOLY Vector Complex Polynomial
The VCPOLY instruction performs one iteration of evaluat-
ing a polynomial with real coefficients for a vector of com-
plex-valued arguments including down-scaling of the coeffi-
cients to avoid overflow In addition the instruction accumu-
lates the scaled-down energy with a decay factor of the
polynomial’s real coefficients
tor is compared with the first element of the extended Z
vector The large value is stored back into the Z vector In
case the larger value was the accumulator then ss is stored
in the second location of the Z-vector (as an integer)
Syntax
EXEC EFMAX
15
11 10
0
10000
101 0100 1011
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