Simultaneous Serial Data Transmission And Reception; (Clocked Synchronous Mode) - Hitachi H8S/2215 Series Hardware Manual

13.6.5 Simultaneous Serial Data Transmission and Reception (Clocked Synchronous
Mode)
Figure 13.23 shows a sample flowchart for simultaneous serial transmit and receive operations.
The following procedure should be used for simultaneous serial data transmit and receive
operations. To switch from transmit mode to simultaneous transmit and receive mode, after
checking that the SCI has finished transmission and the TDRE and TEND flags are set to 1, clear
TE to 0. Then simultaneously set TE and RE to 1 with a single instruction. To switch from receive
mode to simultaneous transmit and receive mode, after checking that the SCI has finished
reception, clear RE to 0. Then after checking that the RDRF and receive error flags (ORER, FER,
and PER) are cleared to 0, simultaneously set TE and RE to 1 with a single instruction.
Rev. 3.0, 10/02, page 403 of 686