R01UH0822EJ0100 Rev.1.00
Page 642 of 1041
Jul 31, 2019
RX13T Group
23. Serial Communications Interface (SCIg, SCIh)
shows an example of data transmission when the SCI is set to asynchronous mode according to the flow
after a reset. When the pin function is set to the TXD pin, it is still high-impedance because the
SCR.TE bit is 0. When the transmit data is written after setting the TE bit to 1, a data transmission starts. After the TE bit
is set to 1, one frame of high is output from TXD pin (internal wait time) and then the data transmission starts.
Figure 23.8
Example of Data Transmission Timing in Asynchronous Mode
Asynchronous mode
Mode
SCR.TE bit
TXD pin
Hi-Z
D0
D2
D1
0
Wait time
Data transmission
Transmit data is written
Pin function is set