
86
Details of the Data Exchange Methods
Section 6-3
6-3-7
Data Exchange Method No. 7
The CPU Unit sends an interrupt to the ASCII Unit, and the ASCII Unit writes
data to the shared memory. After the completion of the interrupt subroutine,
the CPU Unit reads data from the shared memory.
Note
See
6-4-9 Sending Interrupts from CPU Unit to ASCII Unit: PC Interrupts
for
details on PC interrupts.
1,2,3...
1.
The CPU Unit sends an interrupt to the ASCII Unit when the IOWR instruc-
tion (#CC00) is executed in the ladder diagram.
2.
The ASCII Unit receives the interrupt and writes data to the shared mem-
ory using a PC EPUT command.
3.
When a change is detected in the Interrupt Subroutine Completed Flag (1
to 0 or 0 to 1), the shared memory is read when the IORD instruction
(#00
@@
) is executed in the ladder diagram.
The following example is for a C200HX/HG/HE PC.
Note
Refer to the note for method 6 on the previous page.
Interrupt
Shared memory
(IORD Area)
3. Read
CPU Unit
ASCII Unit
2. Write
1.
Interrupt subroutine
completion
2.
IOWR
#CC00
a
#
@
001
DIFD A
DIFU B
IORD
#00
@@
ON PC a GOSUB
PC EPUT
A
B
(See note)
Содержание C200H-ASC11
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