Single-Precision Real/Double-Precision Real Data - Mitsubishi MELSEC-Q Series Programming Manual

(2) Using word devices
Devices used in lower 16 bits are specified for a word device.
'Specified device number' and 'specified device number +1' are used for instructions that
process 32-bit data.
M0
100
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.
(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'.
M0
Var_R100
Two points (32 bits) of R100 and R101 are the target word devices
Remark
b31
b31
Sign
b23 to b30
Transfers 32-bit data
DMOV
EN ENO
s d
D0
Two points (32 bits) of D0 and D1
are the target word devices
Transfers real number data
EMOV
EN ENO
s d
Var_D0
Floating-point data are represented by two word devices.
[Exponent]
[Sign] 1. [Fraction] 2
The following explains the bit configuration and its meaning when floating-point
data are internally represented.
b30 to b23 b22
b23 to b30
Exponent
• Sign
b31 represents a sign.
0: Positive
1: Negative
• Exponent
b23 to b30 represent n of 2
The values of n are as follows according to BIN values of b23 to b30.
FF FE FD
H H H
n
Not used 127 126
• Fraction
23 bits of b0 to b22 represent a value of XXXXXX... when the fraction is
expressed as 1.XXXXXX... in binary.
4.4.4 Single-precision real/double-precision real data
Two points (32 bits) of D0 and D1
are the target word devices
to b16 b15
b0 to b22
Fraction
n
.
81 80 7F 7E
H H H H
2 1 0 -1
4.4 Method for Specifying Data
to b0
02 01 00
H H H
-125 -126 Not used
4-27
4