Mitsubishi Q00JCPU User Manual page 932

APPENDICES
App
- 143 Appendix 5 Method of replacing High Performance model QCPU with Universal model QCPU
(4) Method of replacing High Performance model QCPU with Universal
model QCPU
(a) Replacing all single-precision floating-point operation instructions with
double-precision floating-point operation instructions
Single-precision floating-point data occupy two points of word device per data. On
the other hand, four points are required per double-precision floating-point data.
Therefore, all device numbers for storing floating-point data need to be
reassigned.
Example) Replacing the floating-point operation [A to B+C] (Changing all
floating-point data into double precision.)
1) Device assignment
Before replacement
Application
Data A
Data B
Data C
Data D
2) Program before replacement
3) Program after replacement
Figure App.21 Sample program
TableApp.75 Device assignment
Device Data type
D0 to D1
Floating-point
D2 to D3
data (single
D4 to D5
precision)
D6 to D7
Figure App.20 Sample program
After replacement
Application Device
Data A D0 to D3
Data B D4 to D7
Data C D8 to D11
Data D D12 to D15
Operation is performed using
double-precision floating-point
data.
Data type
Floating-point
data (double
precision)