
B–61863E/15
4. PMC BASIC INSTRUCTIONSPMC SEQUENCE PROGRAM
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(2) Type
There are two types of PMC instructions, basic and functional.
(a) Basic instruction
Basic instructions are most often used when designing sequence
programs. They perform one–bit operations, such as AND, or
OR. There are 14 types.
(b) Functional instruction
Functional instructions ease programming of machine
movements that are difficult to program with basic instructions.
Refer to Chapter 5 about the type of functional instruction.
(3) Storage of logical operation results
A register is provided for storing the intermediate results of a logical
operation during operation of a sequence program. This register
consists of 9 bits. (See Fig. 4 (b) ) .
Stack register (which temporarily stores the inter-
mediate result of an operation)
The result of an operation
currently being executed
enters here.
ST8 ST7 ST6 ST5 ST4 ST3 ST2 ST1 ST0
Fig. 4 (b)
Execution of an instruction (RD.STK or the like) to temporarily store the
intermediate results of an operation as in the above figure, shifts left and
stacks the status stored so far; conversely, execution (AND.STK or the
like) to retrieve a stacked signal shifts it right. The signal stacked last is
retrieved first.
Refer to explanations of each instruction for concrete applications and
operations.