74
Selecting the Data Exchange Method
Section 6-2
6-2
Selecting the Data Exchange Method
Data access at I/O
refresh, or
read/write large
volume of data, or
if the CPU Unit is
other than a
C200HX/HG/HE or
CS1-series PC.
Data
read/write in
words.
Read/write data is
not affected by I/O
refresh when the
CPU Unit is a
C200HX/HG/HE or
CS1-series PC.
Asyn-
chro-
nous
CPU Unit and ASCII
Unit asynchronously
read/write to ASCII
Unit's shared
memory (to speed up
ASCII Unit
processing).
CPU Unit
Data exchange
method number
(Do not need to be
specified in pairs .)
Syn-
chro-
nous
(High-spe-
ed data
exchange
possib l
e)
ASCII
to
CPU
On a trigger from the
ASCII Unit, the CPU
Unit reads/writes I/O
memory data to the
ASCII Unit when the
IOWR/IORD (#FD00)
instruction is
executed.
CPU
to
ASCII
The CPU Unit sends
an interrupt to the
ASCII Unit, and
reads/writes to the
shared memory via
the PC EGET/PC
EPUT commands in
the ASCII Unit
interrupt subroutine .
The CPU Unit
reads/writes the
ASCII Unit's shared
memory.
IOWR (#CC00)
(interrupt)
On a trigger from the
CPU Unit, the ASCII
Unit reads/writes the
memory (255 words
max.).
ASCII
alone
The ASCII Unit
reads/writes the CPU
Unit's memory
independently (255
words max.).
Read/write
data in bit(s).
CPU
to
ASCII
ASCII Unit
Asynchronous
YES
IOWR (#00
@@
)
IORD (#00
@@
)
PC EGET
PC EPUT
YES
IOWR (#FD00)
IORD (#FD00)
PC QREAD@
PC QWRITE@
IOWR (#00
@@
)
IORD (#00
@@
)
YES
ON PC GOSUB
PC EGET
PC EPUT
YES
MOV
PC READ
PC WRITE
YES
None
PC READ@
PC WRITE@
MOV
LD
PC PUT
PC GET
4., 5.
6.
7., 8.
1.
2.
3.
+
Summary of Contents for C200H-ASC11
Page 1: ...C200H ASC11 ASC21 ASC31 ASCII Units Operation Manual Revised June 2000...
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