Instruction Location And Execution Conditions - Omron CJ2 CPU - REV 10-2010 User Manual

5 Understanding Programming
Operands
Operands specify preset instruction parameters (boxes in ladder diagrams) that are used to specify
I/O memory area contents or constants. An instruction can be executed entering an address or con-
stant as the operands. Operands are classified as source, destination, or number operands.
Example
MOV
#0
D0
Source Specifies the address of the data to
be read or a constant.
Destination Specifies the address where data
(Results) will be written.
Number Specifies a particular number used
in the instruction, such as a jump
number or subroutine number.
Note Operands are also called the first operand, second operand, and so on, starting from the top of the instruc-
tion.
MOV
#0
D0

Instruction Location and Execution Conditions

The following table shows the possible locations for instructions. Instructions are grouped into those
that do and those do not require execution conditions. Refer to A-1 Instruction Functions for details on
instructions.
Instruction
Input Logical start
instruc- (Load
tions instructions)
Intermediate
instructions
Output instructions
5-64
S (source)
D (destination)
Operand types
First operand
Second operand
Location
Connected directly to
the left bus bar or is
at the beginning of
an instruction block.
Between a logical
start and the output
instruction.
Connected directly to
the right bus bar.
JMP
&3
N (number)
Operand
symbol
S Source Oper-
and
C Control data
D ---
N ---
Execution
Diagram
condition
Not
required.
Required
Required
Not
required.
Description
Source operand other than con-
trol data (C)
Compound data in a source
operand that has different mean-
ings depending bit status.
Examples
LD, LD TST(350), LD >
(and other symbol com-
parison instructions)
AND, OR, AND
TEST(350), AND > (and
other ADD symbol com-
parison instructions),
UP(521), DOWN(522),
NOT(520), etc.
Most instructions includ-
ing OUT and MOV(021).
END(001), JME(005),
FOR(512), ILC(003),
etc.
CJ2 CPU Unit Software User's Manual