Index Registers (Z) - Mitsubishi Electric MELSEC-Q Series User Manual

10 DEVICES

10.6 Index Registers (Z)

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(1) Definition
(a) Index registers are used in the sequence program for indirect setting (index
qualification) designations.
An index register point is used for index modification.
X0
SM400
(b) There are 10 index registers (Z0 to Z9).
(c) Index registers consist of 16 bits per point, with reading and writing
occurring in 16-bit modules.
b15
Zn
(d) If the index registers are used for 32-bit instructions, the data is stored in
registers Zn and Zn +1.
The lower 16 bits of data are stored in the index register No. (Zn)
designated in the sequence program, and the upper 16 bits of data are
stored in the designated index register No. + 1.
For example, if register Z2 is designated in the DMOV instruction, the lower
16 bits are stored in Z2, and the upper 16 bits are stored at Z3.
REMARK
For index modification using the index register, refer to the following manual.
QCPU (Q mode) / QnACPU Programming Manual (Common instructions)
MOVP K5 Z0
BCD D0Z0 K4Y30
Index registers consist of 16 bits per point.
DMOV D0 Z2
Processing object: Z2, Z3
Upper 16 bits Lower 16 bits
MELSEC-Q
b0
Z3 Z2
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