SH7011 Datasheet, PDF (223/292 Pages) Renesas Technology Corp – CMOS single-chip microprocessors

Initialize
Clear TE and RE bits to 0 in SCR
Set CKE1 and CKE0 bits in SCR (1)
(TE and RE bits are 0)
Select transmit/receive format in SMR (2)
Set value to BRR
(3)
Wait
No
1-bit interval elapsed?
Yes
Set TE or RE to 1 in SCR; Set RIE,
TIE, TEIE, and MPIE as necessary ⁽⁴⁾
End
Figure 12.3 Sample Flowchart for SCI Initialization
Transmitting Serial Data (Asynchronous Mode): Figure 12.4 shows a sample flowchart for
transmitting serial data. The procedure is as follows (the steps correspond to the numbers in the
flowchart):
1. SCI status check and transmit data write: Read the serial status register (SSR), check that the
TDRE bit is 1, then write transmit data in the transmit data register (TDR) and clear TDRE to
0.
2. To continue transmitting serial data: Read the TDRE bit to check whether it is safe to write (if
it reads 1); if so, write data in TDR, then clear TDRE to 0.
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