Pointer (P); Global Pointers; Label Assignment Pointers; Interrupt Pointer (I) - Mitsubishi Electric FX5 User Manual

26.8

Pointer (P)

Device used by instructions such as jump instruction (CJ instruction) and subroutine program call instruction (CALL
instruction, etc.). Types of pointers are as follows.
Pointer

Global pointers

Label assignment pointers

Pointers are used for the following purposes.
• Specifies label and where to jump to for jump instruction (CJ instruction).
• Specifies label (top of subroutine program) and call destination of subroutine instruction (CALL instruction, etc.).
Global pointers
Pointer for calling subroutine from all programs being run.
Program 1 (program group A)
CALL P1000
Program 2 (program group B)
CALL P1001
Precautions when using global pointers
• A global pointer of the same pointer number cannot be set as a label for more than one location.
• The initial pointer number for global pointers is fixed to "0".
Label assignment pointers
Pointer assigned to pointer type labels. Pointer for label assignment are automatically assigned to pointer type labels by
engineering tool. Pointer numbers of pointers for label assignment cannot be directly specified. By defining pointer type
labels, you can specify destination for jump instruction or subroutine program by label instead of pointer such as P0.
26.9

Interrupt Pointer (I)

Device used as label at top of interrupt program. Can be used by all running programs.
Interrupt pointer (interrupt program label)
I
Setting the execution type of program to the event execution type eliminates the need to write (I) the
interrupt pointer. (Page 28 Generation of interrupt by interrupt pointer (I))
26 DEVICES
316
26.8 Pointer (P)
Description
Pointers that can be referred to from all programs.
Pointers used by assignment to labels. Pointer numbers assigned to labels are automatically determined by engineering
tool; the user cannot specify pointer numbers to be assigned.
Program 3 (program group C)
P1000
P1001
Interrupt Program
IRET
RET
RET