Mitsubishi MELSEC-A series, Programming Manual

Page: 355 / 508

8. MICROCOMPUTER MODE
8
−
5
MELSEC-A
4) To return from the microcomputer program to the sequence program, use
the RETF (return to outside the segment) instruction.
CP/M and CP/M-86 are trademarks of Digital Research, Inc.
MS-DOS is a trademark of Microsoft Corporation.
(3) Calling method of microcomputer program
The microcomputer program is called by the execution of SUB instruction in the
sequence program.
The format of the SUB instruction is as shown below.
Fig. 8.2 Format of SUB Instruction
Example:
In the following memory map, the specification of "n" is as shown below.
In the SUB instruction, specify as shown below.
By changing the offset value specified at "n", multiple microcomputer programs can
also be called.
Fig. 8.3 Calling Method for Multiple Microcomputer Programs
n
Offset value of microcomputer program to be
called
Setting data
SUB
n
Microcomputer program call command
Head address of
microcomputer program
area which will be called actually
(offset value)
SUB H33F
0H
500H
Microcomputer program
Microcomputer program
Microcomputer
program mode
Call
Call
SUB H0
SUB
H500
Head address of
microcomputer program
area (offset value) Sequence program area
Microcomputer program area
0H
33FH
Parameter
T/C set value
SUB n
Microcomputer program