Precautions For Serial I/O (In Clock-Synchronous Serial I/O Mode) - Renesas M30245 Series User Manual

M30245 Group

2.3.4 Precautions for Serial I/O (in clock-synchronous serial I/O mode)

Transmission/reception
(1) With an external clock selected, and choosing the RTS function, the output level of the RTSi
pin goes to "L" when the data-receivable status becomes ready, which informs the transmis-
sion side that the reception has become ready. The output level of the RTSi pin goes to "H"
when reception starts. So if the RTSi pin is connected to the CTSi pin on the transmission
side, the circuit can transmission and reception data with consistent timing. With the internal
clock, the RTS function has no effect. Figure 2.3.11 shows an example of wiring.
Figure 2.3.11. Example of wiring
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
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Transmitter side IC
TxD
i
RxD
i
CLK
i
CTS
i
page 53 of 354
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Receiver side IC
TxD
i
RxD
i
CLK
i
RTS
i
2. Clock-Synchronous Serial I/O
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