Renesas H8S Family Hardware Manual page 521

Section 13 Serial Communication Interface (SCI)

Simultaneous Serial Data Transmission and Reception (Clock Synchronous Mode)

Figure 13.20 shows a sample flowchart for simultaneous serial transmit and receive operations.

After initializing the SCI, 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 in SSR are set to 1, clear the TE bit in SCR to 0. Then simultaneously set the TE and RE bits

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 the RE bit to 0. Then after checking

that the RDRF bit in SSR and receive error flags (ORER, FER, and PER) are cleared to 0,

simultaneously set the TE and RE bits to 1 with a single instruction.

Rev. 1.00 Mar. 12, 2008 Page 473 of 1178

REJ09B0403-0100