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5.3. I/O
①
Output data from PC to parallel port. After receiving the data sent from the PC, set the
data 4-bits at a time on the output port. When the data setting is completed, the STB
pulse is output.
Hote) When the amount of received data which is set to output port is exceeded, extra
data will be discarded.
If the received data is less than amount of setting data in an output port, the data
sent last time will be remained in the empty space.
Received data
1
3
2
4
Output port_3 High
Low
High
Low
Output port_4
STB output
1
2
3
4
②
The data that is input from parallel port send to the PC.
Without latch
When ZS-6222 receives the “R” command from the PC, it takes in the data from the
input port and transmits it to PC.
With latch
Data from the input port is captured when the LAH input is LOW.
When ZS-6222 receives the “R” command from the PC, it sends the captured data to
the PC.
500μs or more
Input port
LAH signal
Received data
ABCD
R
A
B
C
D
Transmission
data
