Omron CJ - REFERENCE MANUAL 10-2009 Reference Manual page 547

Sign: -
Exponent:1,024 - 1,023 = 1
Mantissa: 1 + (2
Value: -1.75
(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
bit 2 is 0 and the decimal point follows immediately after it.
Non-normalized numbers are expressed as follows:
(sign s)
(-1)
Example
32
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
64 63
Sign: -
Exponent: -1,022
Mantissa: 0 + (2
Value: -0.75
(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 +
exponent will be 2,047 (2
(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
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.
CS/CJ/NSJ Series Instructions Reference Manual (W474)
51 50 -52
+ 2 ) 2 = 1 + (2
1
2 = -3.5
-1,022 -52
2 (mantissa 2
52 51
51 50 -52
+ 2 ) 2 = 0 + (2
-1,022
2 = 1.668805 10
and - can be expressed by setting the sign to 0 for positive or 1 for negative. The
11
- 1) and the mantissa will be 0.
-1 -2
+ 2 ) = 1 + (0.75) = 1.75
52
- 1), and it is assumed that, in the real mantissa,
)
0
33
-1 -2
+ 2 ) = 0 + (0.75) = 0.75
-308
3. Instructions
8
- 1) and the mantissa will be
3
509