Omron CJ1G-CPUxx, Instructions Manual

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534
Floating-point Math Instructions
Section 3-15
Description /F(457) divides the 32-bit floating-point number in Dd+1 and Dd by the 32-bit
floating-point number in Dr+1 and Dr 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 dividend and divisor data will produce the results
shown in the following table.
Note 1. The results could be zero (including underflows), a numeral, +
∞
, or –
∞
.
2. The results will be zero for underflows.
3. The Error Flag will be turned ON and the instruction won’t be executed.
Flags
Precautions The Dividend (Dd+1 and Dd) and Divisor (Dr+1 and Dr) data must be in
IEEE754 floating-point data format.
Dividend
Divisor 0 Numeral +
∞
–
∞
NaN
0 See note 3. +/–
∞
+
∞
–
∞
Numeral 0 See note 1. +/–
∞
+/–
∞
+
∞
0 See note 2. See note 3. See note 3.
–
∞
0 See note 2. See note 3. See note 3.
NaN See note 3.
R+1 R
Dd
Dividend (floating-point data, 32 bits) Dd+1
Dr
Divisor (floating-point data, 32 bits) Dr+1
Result (floating-point data, 32 bits)
÷
Name Label Operation
Error Flag ER ON if the dividend or divisor data is not recognized as
floating-point data.
ON if the dividend or divisor is not a number (NaN).
ON if the dividend and divisor are both 0.
ON if the dividend and divisor are both +
∞
or –
∞
.
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.