Omron SYSMAC CJ - REFERENCE MANUAL 08-2008

602
Floating-point Math Instructions Section 3-15
Description +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.)
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.
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 augend (Au+1 and Au) and Addend (Ad+1 and Ad) data must be in
IEEE754 floating-point data format.
Augend
Addend 0 Numeral +∞ –∞ NaN
0 0 Numeral +∞ –∞
Numeral Numeral See note 1. +∞
(See note 2.)
–∞
(See note 2.)
+∞ +∞ +∞
(See note 2.)
+∞
See note 3.
–∞ –∞ –∞
(See note 2.)
See note 3. –∞
NaN See note 3.
R+1 R
+
Au
Au+1
Ad
Ad+1
Result (floating-point data, 32 bits)
Augend (floating-point data, 32 bits)
Addend (floating-point data, 32 bits)
Name Label Operation
Error Flag ER 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.
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.