Mitsubishi 00JCPU, Руководство пользователя

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9.6 Index Register (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 points available for the index register are as follows:
• Basic model QCPU: Z0 to Z9 (10 points)
• High Performance model QCPU, Process CPU, Redundant CPU: Z0 to Z15 (16 points)
(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
H
to FFFF
H
can be stored. However, because the most significant bit
represents a sign bit, decimal values that can be specified are -32768 to 32767.
Figure 9.61 Index register
Figure 9.62 Bit structure of the index register
X0
K5 Z0 MOVP
SM400
D0Z0 K4Y30
BCD
Specify the index register
by one point (16 bits).
Zn
b15
to
b0
Most significant bit represents a sign bit.