Omron CP1L CPU UNIT - 03-2009, Operation Manual

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Index Registers Section 4-11
Setting Index Registers Always set the required value in an index register before using it. The contents
of an index register will be unpredictable if it is not set in advance.
The contents of an index register is also unpredictable after an interrupt task
is started. When using index registers inside an interrupt task, use
MOVR(560) (for anything but timer/counter PVs) or MOVRW(561) (for
timer/counter PVs) to set the required value.
Direct Addressing When an Index Register is used as an operand without a “,” prefix, the instruc-
tion will operate on the contents of the Index Register itself (a two-word or
“double” value). Index Registers can be directly addressed only in the instruc-
tions shown in the following table. Use these instructions to operate on the
Index Registers as pointers.
The Index Registers cannot be directly addressed in any other instructions,
although they can usually be used for indirect addressing.
The SRCH(181), MAX(182), and MIN(183) instructions can output the PLC
memory address of the word with the desired value (search value, maximum,
or minimum) to IR0. In this case, IR0 can be used in later instructions to
access the contents of that word.
Instruction group Instruction name Mnemonic
Data Movement
Instructions MOVE TO REGISTER MOVR(560)
MOVE TIMER/COUNTER PV TO REG-
ISTER MOVRW(561)
DOUBLE MOVE MOVL(498)
DOUBLE DATA EXCHANGE XCGL(562)
Table Data Processing
Instructions SET RECORD LOCATION SETR(635)
GET RECORD NUMBER GETR(636)
Increment/Decrement
Instructions DOUBLE INCREMENT BINARY ++L(591)
DOUBLE DECREMENT BINARY – –L(593)
Comparison Instructions DOUBLE EQUAL =L(301)
DOUBLE NOT EQUAL
< >
L(306)
DOUBLE LESS THAN
<
L(311)
DOUBLE LESS THAN OR EQUAL
<
=L(316)
DOUBLE GREATER THAN
>
L(321)
DOUBLE GREATER THAN OR EQUAL
>
=L(326)
DOUBLE COMPARE CMPL(060)
Symbol Math Instructions DOUBLE SIGNED BINARY ADD WITH-
OUT CARRY
+L(401)
DOUBLE SIGNED BINARY SUBTRACT
WITHOUT CARRY –L(411)