Mitsubishi Melsec A User Manual page 49

6. AD51 PROGRAMMING NOTES
/MELSEC
(3)
The work area must come after the text area and the work area
head address must have 00 in the t w o least significant digits.
256 bytes are used for the BASlC interpreter work area starting
at the work area head address.
(4) When t w o or more tasks are written in the same channel make
sure that the program areas and BASlC interpreter work areas do
n o t overlap each other.
a) Program data will be corrupted in overlapping memory areas.
b ) Multitasking results will be invalid if the BASlC interpreter
work area for a given task is overlapped b y program data
from a different task. Independent running o f that task
however is valid.
Correct
exam~le
Over-
lapping
program
area
Over-
lapping
lterprete
vork area
BASlC Program Addresses
Task
Program head address
Program last address
Additional program head address
Work area head address
Channel
Task
Program head address
Program last address
Additional program head address
Work area head address
Channel
Task
Program head address
Program last address
Additional program head address
Work area head address
Channel
TASK 1
1
8 0 0 0 H
AFFFH
A74CH
FOOOH
1
1
8 0 0 0 H
AFFFH
A74CH
FOOOH
1
1
8 0 0 0 H
AFFFH
A74CH
FOOOH
1
TASK
i
2
BOOOH
DFFFH
C851 H
F 8 0 0 H
1
-
2
AOOOH
DFFFH
8851 H
F 8 0 0 H
1
2
BOOOH
DFFFH
C851 H
FOOOH
1
Memory Map
8000H
B A S l C text area ltask 1)
BOOOH
BASlC text area (task 21
DFFFH
BASlC interpreter work area Itark
'
BASlC interpreter work area Itark
:
FFFFH
BOOOH
BASlC rexr area (task 1 )
3FFFH Overlailping area
BASIC text area ltark 2)
> F F F H
BASlC interpreter work area ltark 1
BASIC interpreter work area ltark i
FFFFH
8000H
BASlC
t e x t
area ltark 11
BOOOH
O H
[
B A S l C
t e x t
area ltark 21
FOOOH
BASlC interpreter work area ltask 1
BASlC
interpreter
work area (task 2
F F F F H