Hitachi SH7750 Hardware Manual page 699

Transfer
direction
Serial clock
Serial data
RDRF
ORER
RXI interrupt
request
Simultaneous Serial Data Transmission and Reception (Synchronous Mode): Figure 15.23
shows a sample flowchart for simultaneous serial transmit and receive operations.
Use the following procedure for simultaneous serial data transmit and receive operations after
enabling the SCI for transmission and reception.
Bit 7 Bit 0
Data read from
SCRDR1 and RDRF
flag cleared to 0 in RXI
interrupt handler
One frame
Figure 15.22 Example of SCI Receive Operation
Bit 7 Bit 0 Bit 1
RXI interrupt
request
Rev. 6.0, 07/02, page 649 of 986
Bit 6 Bit 7
ERI interrupt
request due to
overrun error