Specifications

4.4 Method for Specifying Data
4.4.4 Single-precision real/double-precision real data
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4
PROGRAM CONFIGURATION
4.4.4 Single-precision real/double-precision real data
Single-precision real/double-precision real data are 32-bit floating-point data used in basic
instructions and application instructions.
Real number data can be stored only in word devices.
For FXCPU, double-precision real data is not supported.
(1) Single-precision real (single-precision floating-point data)
Devices used in lower 16 bits are specified for instructions that use real number data.
Real number data are stored in 32 bits of 'specified device number' and 'specified device number +1'.
Remark
Floating-point data are represented by two word devices.
[Sign] 1. [Fraction] 2
[Exponent]
The following explains the bit configuration and its meaning when floating-point
data are internally represented.
•Sign
b31 represents a sign.
0: Positive
1: Negative
• Exponent
b23 to b30 represent n of 2
n
.
The values of n are as follows according to BIN values of b23 to b30.
•Fraction
23 bits of b0 to b22 represent a value of XXXXXX... when the fraction is
expressed as 1.XXXXXX... in binary.
(2) Double-precision real (double-precision floating-point data)
Devices used in lower 16 bits are specified for instructions that use real number data.
Real number data are stored in 64 bits of 'specified device number' and 'specified device
number + 3'.
M0
EMOV
EN ENO
d
s
Var_R100
Var_D0
Two points (32 bits) of R100 and R101 are the target word devices
Two points (32 bits) of D0 and D1
are the target word devices
Transfers real number data
b31 b3
0
to
b23
b22 b16
to
b15 b0
to
b31
Sign
b23 to b30
Exponent
b0 to b22
Fraction
b23 t
o b30
FFH FEH FDH 81H 80H 7FH 7EH 02H 01H 00H
n
Not used 127
126
2
1 0 -1
-125
-126
Not used