Hitachi H8/329 Series Hardware Manual page 213

Figure 8-16 shows an example of SCI receive operation.
Serial clock
Data Bit 0
RDRF
ORER
RXI
request
Bit 1 Bit 7
RXI interrupt
handler reads
data in RDR and
clears RDRF to "0"
1 frame
Figure 8-16. Example of SCI Receive Operation
Bit 0 Bit 1
RXI
request
204
Bit 6 Bit 7
Overrun error,
ERI request