Fseedd reciprocal approximation fseedd – Motorola DSP96002 User Manual
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DSP96002 USER’S MANUAL
MOTOROLA
FSEEDD
Reciprocal Approximation
FSEEDD
Operation:
Approximation(1/S)
→
D
Assembler Syntax:
FSEEDD S,D
Description:
Take the contents of the specified source operand S, determine an approximation to 1.0/S, and store the
result in the destination operand D. The 9 MSBs of the destination significand are determined by using a
lookup ROM. The remaining bits of the significand are zeroed. This instruction is useful for initializing
floating-point divide algorithms.
The table below describes the operation of the FSEEDD instruction:
Source Operand
Result
SNaN or QNaN
QNaN
+/- zero
+/- infinity
+/- denormalized
normalized, then FSEEDD approximation
+/- normalized
FSEEDD approximation
+/- infinity
+/- zero
Input Operand(s) Precision: SEP Floating-Point.
Output Operand Precision: SEP Floating-Point.
CCR Condition Codes:
C
- Not affected.
V
- Not affected.
Z
- Set if result is zero. Cleared otherwise.
N
- Set if result is negative. Cleared otherwise.
I
- Set if result is infinity. Cleared otherwise.
LR
- Not affected.
–
R
- Not affected.
A
- Not affected.