Mitsubishi Electric melsec q00ujcpu User Manual page 413

(4) Checking the points by the special register
The points for each of the file register (ZR), extended data register (D), and extended link register (W) can be
checked in the following special register areas.
• SD306, SD307: File register (ZR)
• SD308, SD309: Extended data register (D)
• SD310, SD311: Extended link register (W)
(5) Precautions
For use of the extended data register (D) and extended link register (W), pay attention to the following.
1) When the extended data register (D) and extended link register (W) are specified, the values of the
following items will be the same as those for the file register (ZR).
• Number of program steps
• Instruction processing time
• Processing time of auto refresh with network modules
• Processing time of auto refresh with intelligent function modules
• Processing time of auto refresh between CPU shared memories
2) The file register size cannot be changed in the RUN status.
3) The file register cannot be switched to another using the QDRSET instruction. ("OPERATION ERROR"
(error code: 4100))
4) Set the refresh ranges for the following auto refresh properly so that each refresh range does not cross over
the boundary between the internal user device and the extended data register (D) or extended link register
(W).
• Auto refresh with network modules
• Auto refresh with intelligent function modules
• Auto refresh between CPU shared memories
5) Set the following properly so that each specification does not cross over the boundary between the internal
user device and the extended data register (D) or extended link register (W).
• Index modification
• Indirect specification
• Specification for instructions that use block data
*1: Block data means the following:
•
Data used in instructions, such as FMOV, BMOV, and BK+, which treat more than one word for operation.
•
Control data, composed of two or more words, which are specified in instructions, such as SP.FWRITE and SP.FREAD.
•
Data in a 32-bit or greater format (binary 32 bits, real number, indirect address of a device)
Remark
For details on the index modification and indirect specification with the extended data register (D) and extended link
register (W), refer to the following.
QCPU Programming Manual (Common Instructions)
9 - 68
*1