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APPLICATION
2.3 Serial I/O
2-47
3802 GROUP USER’S MANUAL
(4) Communication (transmit/receive) using an asynchronous serial I/O (UART)
Point : 2-byte data is transmitted and received through an asynchronous serial I/O.
The port P40 is used for communication control.
Figure 2.3.36 shows a connection diagram, and Figure 2.3.37 shows a timing chart.
Fig. 2.3.36 Connection diagram [Communication using UART]
Transmitting side
P40
3802 group
P40
3802 group
Receiving side
TXD
X
D
R
Specifications : The Serial I/O1 is used (UART is selected).
Transfer bit rate : 9600 bps (f(XIN) = 4.9152 MHz is divided by 512)
Communication control using port P40
(The output level of the port P40 is controlled by softoware.)
2-byte data is transferred from the transmitting side to the receiving side at inter-
vals of 10 ms (generated by timer).
Fig. 2.3.37 Timing chart [Communication using UART]
P40
TXD
10 ms
D0
D1 D2 D3 D4 D5 D6
D7
ST
SP(2)
D0 D1 D2 D3
D4 D5 D6 D7
ST
SP(2)
D0
ST