SH7018 Datasheet, PDF (263/431 Pages) Renesas Technology Corp – SuperH™ RISC engine

Start of initialization
Clear TE and RE bits to 0 in SCR1
Set RIE, TIE, TEIE, MPIE, CKE1,
and CKE0 bits in SCR
(1)
(TE and RE are 0)
Select transmit/receive
format in SMR1
(2)
Set value in BRR1
(3)
Wait
No
1-bit interval elapsed?
Yes
Set TE and RE to 1 in SCR1;
Set RIE, TIE, TEIE, and MPIE bits ⁽⁴⁾
End
Figure 12.15 Sample Flowchart for SCI Initialization
Transmitting Serial Data (Clock Synchronous Mode): Figure 12.16 shows a sample flowchart
for transmitting serial data and indicates the procedure to follow.
1. SCI1 initialization: Set the TxD pin function with the PFC.
2. SCI1 status check and transmit data write: Read SSR1, check that the TDRE flag is 1, then
write transmit data in TDR1 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 TDR1, then clear the TDRE flag to 0. When the DMAC or
DTC is activated by a transmit-data-empty interrupt request (TxI) to write data in TDR1, the
TDRE flag is checked and cleared automatically.
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