Mitsubishi Q00JCPU User Manual page 696

10
DEVICE EXPLANATION
10
- 81 10.7 File Register (R)
10.7.6 Precautions for using file registers
(b) File register capacity check
When writing/reading data to/from the file register, check the file register capacity
so that data is written/read within the capacity (points) set to the CPU module.
1) File register capacity checking method
The available file register capacity can be checked in the file register capacity
storage register (SD647).
The file register capacity is stored in SD647 in 1k point units.
* 1 : If a file register file is switched to another, the file register capacity of the currently selected file
register file is stored in SD647.
POINT
The "less than 1k points" surplus portion of a file register capacity is not stored.
In order to ensure an accurate "range of use" check, be sure to designate the file
register setting in 1k point (1024 points) units.
2) Checking timing
• A file register capacity check should be executed at step 0 of programs in
which file registers are used.
• After switching to another file register file using the QDRSET instruction,
execute a file register capacity check.
• When using the RSET instruction to switch blocks, confirm that the
switching destination block has a capacity of 1k points or more before
executing the RSET instruction.
(File register capacity) > [32k points
*1
(switching block No.) + 1k points]