SH7709S Datasheet, PDF (547/807 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series

Serial Data Transmission: The processing procedures in the smart card mode differ from
ordinary SCI processing because data is retransmitted when an error signal is sampled during a
data transmission. This results in the transmission processing flowchart shown in figure 15.6.
1. Initialize the smart card interface mode as described in Initialization above.
2. Check that the FER/ERS bit in SCSSR is cleared to 0.
3. Repeat steps 2 and 3 until the TEND flag in SCSSR is set to 1.
4. Write the transmit data into SCTDR, clear the TDRE flag to 0 and start transmitting. The
TEND flag will be cleared to 0.
5. To transmit more data, return to step 2.
6. To end transmission, clear the TE bit to 0.
This processing can be interrupted. When the TIE bit is set to 1 and interrupt requests are enabled,
a transmit-data-empty interrupt (TXI) will be requested when the TEND flag is set to 1 at the end
of transmission. When the RIE bit is set to 1 and interrupt requests are enabled, a communication
error interrupt (ERI) will be requested when the ERS flag is set to 1 when an error occurs in
transmission. See Interrupt Operation below for more information.
Rev. 5.00, 09/03, page 503 of 760