Omron CJ - INSTRUCTIONS User Manual

517
3. Instructions
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Double-precision Floating-point Instructions
3
Double-precision Floating-point Instructions
Sign: -
Exponent:1,024 - 1,023 = 1
Mantissa: 1 + (2
51
+ 2
50
) × 2
-52
= 1 + (2
-1
+ 2
-2
) = 1 + (0.75) = 1.75
Value: -1.75 × 2
1
= -3.5
(2) Non-normalized numbers
Non-normalized numbers express real numbers with very small absolute values. The sign bit will
be 0 for a positive number and 1 for a negative number.
The exponent (e) will be 0, and the real exponent will be -1,022.
The mantissa (f) will be expressed from 1 to (2
52
- 1), and it is assumed that, in the real mantissa,
bit 2
52
is 0 and the decimal point follows immediately after it.
Non-normalized numbers are expressed as follows:
(-1)
(sign s)
× 2
-1,022
× (mantissa × 2
-52
)
Example
Sign: -
Exponent: -1,022
Mantissa: 0 + (2
51
+ 2
50
) × 2
-52
= 0 + (2
-1
+ 2
-2
) = 0 + (0.75) = 0.75
Value: -0.75 × 2
-1,022
= 1.668805 × 10
-308
(3) Zero
Values of +0.0 and -0.0 can be expressed by setting the sign to 0 for positive or 1 for negative. The
exponent and mantissa will both be 0. Both +0.0 and -0.0 are equivalent to 0.0. Refer to Floating-
point Arithmetic Results, below, for differences produced by the sign of 0.0.
(4) Infinity
Values of +∞ and -∞ can be expressed by setting the sign to 0 for positive or 1 for negative. The
exponent will be 2,047 (2
11
- 1) and the mantissa will be 0.
(5) NaN
NaN (not a number) is produced when the result of calculations, such as 0.0/0.0, ∞/∞, or ∞-∞, does
not correspond to a number or infinity. The exponent will be 255 (2
8
- 1) and the mantissa will be
not 0.
Note There are no specifications for the sign of NaN or the value of the mantissa field (other than to be not 0).
 Floating-point Arithmetic Results
(1) Rounding Results
The following methods will be used to round results when the number of digits in the accurate
result of floating-point arithmetic exceeds the significant digits of internal processing expressions.
• If the result is close to one of two internal floating-point expressions, the closer expression will
be used. If the result is midway between two internal floating-point expressions, the result will
be rounded so that the last digit of the mantissa is 0.
00000000000000000000000000000000
00000000000011000000000000000000
64 63 5152 33
32
0

Omron CJ - INSTRUCTIONS Specifications

General

Brand	Omron
Model	CJ - INSTRUCTIONS
Category	Controller
Language	English