Index Register (Z)/Standard Device Resister (Z) - Mitsubishi Electric melsec q00ujcpu User Manual

9.6 Index Register (Z)/Standard Device Resister (Z)

9.6.1 Index register (Z)
(1) Definition
The index register is used for indirect specification (index modification) in sequence programs.
Index modification uses one point of the index register.
The index register has 20 points (Z0 to Z19).
(2) Bit structure of the index register
(a) Bit structure and read/write unit
One point of the index register consists of 16 bits, and data can be read or written in units of 16 bits.
Index register data are handled as signed data.
In the case of the hexadecimal notation, 0000
represents a sign bit, decimal values that can be specified are -32768 to 32767.
9 - 46
X0
MOVP
SM400
BCD
Figure 9.58 Index register
b15
Zn
Most significant bit represents a sign bit.
Figure 9.59 Bit structure of the index register
to FFFF
H
K5 Z0
D0Z0 K4Y30
Specify the index register
by one point (16 bits).
to
can be stored. However, because the most significant bit
H
b0