HD64F7051SFJ20V Datasheet, PDF (439/843 Pages) Renesas Technology Corp – Hardware Manual Renesas 32-Bit RISC

Section 13 Serial Communication Interface (SCI)
Transmitting Serial Data (Synchronous Mode): Figure 13.18 shows a sample flowchart for
transmitting serial data and indicates the procedure to follow.
1. SCI initialization: Set the TxD pin function with the PFC.
2. SCI status check and transmit data write: Read SSR, check that the TDRE flag is 1, then write
transmit data in TDR and clear the TDRE flag to 0.
3. To continue transmitting serial data: After checking that the TDRE flag is 1, indicating that
data can be written, write data in TDR, then clear the TDRE flag to 0. When the DMAC is
activated by a transmit-data-empty interrupt request (TXI) to write data in TDR, the TDRE
flag is checked and cleared automatically.
Rev. 5.00 Jan 06, 2006 page 417 of 818
REJ09B0273-0500