88
3.2.4
Using real number data
Real number data is floating decimal point data used with basic instructions and application instructions.
Only word devices are capable of storing real number data.
(1) Single-precision floating-point data
Instructions which deal with single-precision floating-point data designate devices which are used for the lower 16 bits of
data.
Single-precision floating-point data are stored in the 32 bits which make up (designated device number) and (designated
device 1).
Remark
In sequence programs, floating decimal point data are designated by E
.
Single-precision floating-point data uses two word devices and is expressed in the following manner:
[Sign] 1. [Mantissa part] 2
[Exponent part]
The bit configuration and meaning of the internal representation of single-precision floating-point data is as
follows:
• Sign The sign is represented at b31.
0: Positive
1: Negative
• Exponent part The n of 2n is represented from b23 to b30.
Depending on the BIN value of b23 to b30, the value of n is as follows:
• Variable part The 23 bits from b0 to b22, represents the XXXXXX... at binary 1.XXXXXX....
(2) Double-precision floating-point data
Instructions which deal with double-precision floating-point datadesignate devices which are used for the lower 16 bits of
data.
Double-precision floating-point data are stored in the 64 bits which make up (designated device number) to (designated
device 3).
D
esi
g
nati
o
n
o
f
2
p
o
ints
o
f
R100
an
d
R101
(32
bits
)
M0
E
MO
V
R100
D0
D
esi
g
nati
o
n
o
f
2
p
o
ints
o
f w
o
r
d
d
e
v
ices
D0
an
d
D1
(32
bits
)
S
in
g
le-precisi
o
n fl
o
atin
g
-p
o
int
d
ata transfer instructi
o
n
b
31
b
30
t
o
b
23
b
22
b
1
6
t
o
b
1
5
b
0
t
o
b
31
S
i
g
n
b
23
t
o
b
30
Exp
o
nent part
b
0
t
o
b
22
M
antissa part
b
23
t
o
b
30
FF
H
FE
H
FD
H
8
1
8
0
7
F
H
7
E
H
02
01
00
n
No
t
use
d 12
7
12
6
2
1
0
-1
-12
5
-12
6
No
t
use
d
D
esi
g
nati
o
n
o
f 4 p
o
ints
o
f
R100,
R101,
R102
an
d
R103
(
64 bits
)
M0
E
DMO
V
R100
D0
D
esi
g
nati
o
n
o
f 4 p
o
ints
o
f w
o
r
d
d
e
v
ices
D0,
D1,
D2
an
d
D3
(
64 bits
)
Do
uble-precisi
o
n fl
o
atin
g
-p
o
int
d
ata transfer
instructi
o
n
