HD64F2149 Datasheet, PDF (476/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Figure 15.4 shows a sample SCI initialization flowchart.
Start initialization
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
[1]
(TE, RE bits 0)
Set data transfer format in
SMR and SCMR
Set value in BRR
Wait
1-bit interval elapsed?
Yes
[2]
[3]
No
Set TE and RE bits in
SCR to 1, and set RIE, TIE, TEIE,
[4]
and MPIE bits
[1] Set the clock selection in SCR.
Be sure to clear bits RIE, TIE,
TEIE, and MPIE, and bits TE and
RE, to 0.
When the clock is selected in
asynchronous mode, it is output
immediately after SCR settings are
made.
[2] Set the data transfer format in SMR
and SCMR.
[3] Write a value corresponding to the
bit rate to BRR. This is not
necessary if an external clock is
used.
[4] Wait at least one bit interval, then
set the TE bit or RE bit in SCR to 1.
Also set the RIE, TIE, TEIE, and
MPIE bits.
Setting the TE and RE bits enables
the TxD and RxD pins to be used.
<Initialization completed>
Figure 15.4 Sample SCI Initialization Flowchart
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