Zenisu Keisoku ZS-6822, User Manual, Page: 20 / 25

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6.3.I/O operation
① Output data from PC to port.

Continuous output
Data is set in 4 bits to the port set as output, after receiving data from the PC. The
STB pulse is output after setting the data to the output port.
Note) If data is sent more than amount of data that is set on the output port, extra
data will be discarded. If data is sent less than amount of data that is set on the
output port, the data sent last time will remain in the space.
Received data
1
3
2
4
Output
port_3
High
Low
High
Low
Output
port_4
STB output
1 2 3 4

Pulse output
Data is set 4 bits to the port set as output after receiving data from the PC. The
output port data is output for the specified pulse width.
② Send data input from port to PC.

Without latch
When the ZS-6822 received the “R” command from the PC, it takes in the data from
the input port at that time and sends it to the PC.

With latch
Data from the input port is taken when the LAH input is LOW. When the ZS-6822
receives the “R” command from the PC, it sends the captured data to the PC.
500us or more
Input port
LAH signal
Received
data
ABCD
R
A B C D
Transmission
data