3069RF-ZTAT Datasheet, PDF (509/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

Figure 13.4 shows a sample flowchart for initializing the SCI.
Start of initialization
Clear TE and RE bits
to 0 in SCR
Set CKE1 and CKE0 bits in SCR
(leaving TE and RE bits
(1)
cleared to 0)
Select communication format ₍₂₎
in SMR
Set value in BRR
(3)
Wait
No
1-bit interval elapsed?
Yes
Set TE or RE bit to 1 in SCR (4)
Set the RIE, TIE, TEIE, and
MPIE bits
(1) Set the clock source in SCR. Clear the
RIE, TIE, TEIE, MPIE, TE, and RE bits to
0. If clock output is selected in asynchro-
nous mode, clock output starts immedi-
ately after the setting is made in SCR.
(2) Select the communication format in SMR.
(3) Write the value corresponding to the bit
rate in BRR.
This step is not necessary when an
external clock is used.
(4) Wait for at least the interval required to
transmit or receive one bit, then set the
TE or RE bit to 1 in SCR. Set the RIE,
TIE, TEIE, and MPIE bits as necessary.
Setting the TE or RE bit enables the SCI
to use the TxD or RxD pin.
<End of initialization>
Note: In simultaneous transmitting and receiving, the TE and RE bits should be cleared to
0 or set to 1 simultaneously.
Figure 13.4 Sample Flowchart for SCI Initialization
Rev. 5.0, 09/04, page 487 of 978