3
- 90
3.9 Numeric Values which can be Used in Sequence Programs
3.9.4 Real numbers (Floating-point data)
3
SEQUENCE PROGRAM CONFIGURATION AND
EXECUTION CONDITIONS
(2) Double-precision floating-point data
(a) Internal expression of real number data
The following shows the internal expression of real number data dealt with the
Universal model QCPU.
Using four word deices, the real number data is expressed as follows:
[Sign] 1.[Mantissa] 2
(exponent part)
The bit configuration of internal expression for the real number data is as follows:
1) Sign
The b63 shows a sign.
0: Positive
1: Negative
2) Exponent part
The “n” of 2n is expressed by b52 to b62, depending on the BIN value in b52
to b62.
3) Mantissa:
For a binary number “1.XXXXXX.....”, the “XXXXXX.....” portion is expressed
by 52 bits (b0 to b51).Note39
Figure 3.72 Bit configuration of real number data
Figure 3.73 Relation between value stored in exponent part and exponent
Note39
High
Performance
Process
Redundant
Basic
Note3.40
Note3.40
Note3.40
Note3.40
b63
b62
to
b52
b51
to
b16
b15
to
b0
b63
b0 to b51
Mantissa (52bit)
b52 to b62
Exponent part (11bit)
Sign
b52 to b62
n
7FF
H
Not used
7FE
H
1023
7FD
H
1022
00
H
Not used
02
H
-1021
01
H
-1022
400
H
2
3FF
H
1
3FE
H
0
3FD
H
-1
3FC
H
-2
The Basic model QCPU, High Performance model QCPU, Process CPU, and Redundant CPU
cannot use the double-precision floating-point data.
High
Performance
Process
Redundant
Basic
