APPENDICES
Appendix 5 Method of replacing High Performance model QCPU with Universal model QCPU
App
- 146
9
P
a
ra
met
e
rs
10
Device
Exp
la
n
at
ion
11
CP
U
M
odu
le
P
ro
cessi
ng
Ti
m
e
12
P
roc
e
d
ure
f
or W
rit
in
g
P
rog
ra
m t
o CP
U Mo
du
le
A
p
pe
nd
ic
e
s
In
de
x
(c) Replacing a part of floating-point operation instructions with double-
precision floating-point operation instructions using subroutine programs
The flow of a replacement program described in (b) can be regarded as one
subroutine program. Create subroutine programs for each floating-point operation
instruction and then replace the original floating-point operation instructions with
the CALL(P) instructions so that subroutine programs are called.
With this method, changes in the program are minimized, but the processing for
calling subroutine programs increases the scan time. In addition, since
conversions from double precision to single precision are performed for each
instruction, rounding-off errors generated during operations are larger than those
in the replacement program described in (b).
Example) Replacing the floating-point operation [A B+C] (Using a
subroutine program)
1) Device assignment
2) Program before replacement
TableApp.77 Device assignment
Before replacement
After replacement
Application
Device
Data type
Application
Device
Data type
Data A
D0 to D1
Floating-point
data (single
precision)
Data A
D0 to D1
Floating-point
data (single
precision)
Data B
D2 to D3
Data B
D2 to D3
Data C
D4 to D5
Data C
D4 to D5
Operation
result
D6 to D7
Operation
result
D6 to D7
Data A (D)
D900 to D903
Floating-point
data (double
precision)
Data B (D)
D904 to D907
Data C (D)
D908 to D911
Figure App.24 Sample program
