R01UH0823EJ0100 Rev.1.00
Page 1024 of 1823
Jul 31, 2019
RX23W Group
33. 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 33.9
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