Datasheet

Section 13 Serial Communication Interface (SCI)
Rev. 2.00 Aug. 20, 2008 Page 471 of 1198
REJ09B0403-0200
Figure 13.17 shows a sample flowchart for serial data transmission. Even if the TDRE flag is
cleared to 0, transmission will not start while a receive error flag (ORER, FER, or PER) is set to 1.
Make sure to clear the receive error flags to 0 before starting transmission. Note that clearing the
RE bit to 0 does not clear the receive error flags.
Transfer direction
Bit 0
Serial data
Synchronization
clock
1 frame
TDRE
TEND
Data written to TDR
and TDRE flag cleared
to 0 in TXI interrupt
service routine
TXI interrupt
request generated
Bit 1 Bit 7 Bit 0 Bit 1 Bit 6 Bit 7
TXI interrupt
request generated
TEI interrupt request
generated
Figure 13.16 Sample SCI Transmission Operation in Clock Synchronous Mode