Motorola DSP96002 User Manual page 368

GETEXP
Operation:
Exponent(S) D.L (parallel data bus move)
Description:
Extract the exponent of the single extended precision floating-point operand S and store it as an unbiased,
2's complement, 32-bit integer in the low portion of D . The exponent value is decremented by the number
of shifts needed to normalize the mantissa if the floating-point number was denormalized.
As an example of the use of FGETMAN, GETEXP, and FSCALE; consider decomposing a floating-point
number into its mantissa and unbiased exponent and then recreating the original floating-point number.
FGETMAN
GETEXP
MOVE
FSCALE.S
The following table lists the results for some special cases:
Source operand
+/- infinity
+/- zero
SNaN or QNaN
Input Operand(s) Precision: SEP Floating-Point.
Output Operand Precision: 32-bit integer.
CCR Condition Codes:
C
V
Z
N
I
LR
–
R
A
A - 180
Extract Exponent
D0, D1
D0,D2
D2.L, D2.H
D2.H, D1
Result
$7FFFFFFF
$80000000
$FFFFFFFF
- Not affected.
- Not affected.
- Set if result is zero. Cleared otherwise.
- Set if result is negative. Cleared otherwise.
- Set if the source operand is infinity. Cleared otherwise.
- Not affected.
- Not affected.
- Not affected.
DSP96002 USER'S MANUAL
Assembler Syntax:
GETEXP S,D
(move syntax - see the Move instruction description.)
;extract normalized mantissa
;extract unbiased exponent
;move unbiased exponent
;scale original mantissa
GETEXP
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