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607
Floating-point Math Instructions
Section 3-15
Description
*
F(456) multiplies the 32-bit floating-point number in Md+1 and Md by the 32-
bit floating-point number in Mr+1 and Mr and places the result in R+1 and R.
(The floating point data must be in IEEE754 format.)
If the absolute value of the result is greater than the maximum value that can
be expressed as floating-point data, the Overflow Flag will turn ON and the
result will be output as
±∞
.
If the absolute value of the result is less than the minimum value that can be
expressed as floating-point data, the Underflow Flag will turn ON and the
result will be output as 0.
The various combinations of multiplicand and multiplier data will produce the
results shown in the following table.
Note
1.
The results could be zero (including underflows), a numeral, +
∞
, or –
∞
.
2.
With CJ1H-CPU
@@
H-R CPU Units, an undetermined value will be output.
3.
The Error Flag will be turned ON and the instruction will not be executed.
Flags
Precautions
The Multiplicand (Md+1 and Md) and Multiplier (Mr+1 and Mr) data must be in
IEEE754 floating-point data format.
Multiplicand
Multiplier
0
Numeral
+
∞
–
∞
NaN
0
0
0
See note 3.
See note 3.
Numeral
0
See note 1.
+/–
∞
(See note 2.)
+/–
∞
(See note 2.)
+
∞
See note 3.
+/–
∞
(See note 2.)
+
∞
–
∞
–
∞
See note 3.
+/–
∞
(See note 2.)
–
∞
+
∞
NaN
See note 3.
R+1
R
Md
Multiplicand (floating-point data, 32 bits)
Md+1
Mr
Multiplier (floating-point data, 32 bits)
Mr+1
Result (floating-point data, 32 bits)
×
Name
Label
Operation
Error Flag
ER
ON if the multiplicand or multiplier data is not recognized
as floating-point data.
ON if the multiplicand or multiplier is not a number (NaN).
ON if +
∞
and 0 are multiplied.
ON if –
∞
and 0 are multiplied.
OFF in all other cases.
Equals Flag
=
ON if both the exponent and mantissa of the result are 0.
OFF in all other cases.
Overflow Flag
OF
ON if the absolute value of the result is too large to be
expressed as a 32-bit floating-point value.
Underflow Flag
UF
ON if the absolute value of the result is too small to be
expressed as a 32-bit floating-point value.
Negative Flag
N
ON if the result is negative.
OFF in all other cases.
Summary of Contents for SYSMAC CS1D-CPU**
Page 3: ...iv...
Page 29: ...xxx...
Page 185: ...146 List of Instructions by Function Code Section 2 4...
Page 1389: ...1350 CJ series Instruction Execution Times and Number of Steps Section 4 2...
Page 1390: ...1351 Appendix A ASCII Code Table ASCII SP Four leftmost bits Four rightmost bits...
Page 1391: ...1352 ASCII Code Table Appendix A...