3.
Interrupt program
The following processing is added to a fixed scan interrupt program (10ms).
The fixed scan interrupt program outputs ASCII codes from the output module and controls the strobe
signal.
APPENDICES
The following signals are
all turned off when all
strings are output.
Yn0 to Yn7 (ASCII code)
Yn8 (strobe signal)
Yn9 (in-execution flag)
Status 0:
One character is extracted
from the output string using
the MIDR instruction and
output to the Y module.
The strobe signal is turned
off for 10ms.
Status 1:
The strobe signal is turned on for
10ms.
Status 2:
The strobe signal is turned off
for 10ms.
The status value is incremented
by one.
Status 3:
The status value is returned
to 0 since the output
processing of one character
is completed. The next
character is extracted.
521
A