Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 642

Floating-point Math Instructions
Description
Note
Flags
Precautions
602
+F(454) adds the 32-bit floating-point number in Ad+1 and Ad to the 32-bit
floating-point number in Au+1 and Au and places the result in R+1 and R.
(The floating point data must be in IEEE754 format.)
Au+1
+ Ad+1
R+1
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 augend and addend data will produce the results
shown in the following table.
Addend 0
0 0
Numeral Numeral
+ +
– –
NaN
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.
Name Label
Error Flag ER
Equals Flag =
Overflow Flag OF
Underflow Flag UF
Negative Flag N
The augend (Au+1 and Au) and Addend (Ad+1 and Ad) data must be in
IEEE754 floating-point data format.
Augend (floating-point data, 32 bits)
Au
Addend (floating-point data, 32 bits)
Ad
Result (floating-point data, 32 bits)
R
.
Augend
Numeral +
Numeral +
See note 1. +
(See note 2.)
+ +
(See note 2.)
– See note 3.
(See note 2.)
Operation
ON if the augend or addend data is not recognized as
floating-point data.
ON if the augend or addend data is not a number (NaN).
ON if + and – are added.
OFF in all other cases.
ON if both the exponent and mantissa of the result are 0.
OFF in all other cases.
ON if the absolute value of the result is too large to be
expressed as a 32-bit floating-point value.
ON if the absolute value of the result is too small to be
expressed as a 32-bit floating-point value.
ON if the result is negative.
OFF in all other cases.
Section 3-15
– NaN
–
–
(See note 2.)
See note 3.
–
See note 3.