h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 415

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

13.4.4
Before transmitting and receiving data, first clear the TE and RE bits in SCR to 0, then initialize
the SCI as described below. When the operating mode, or transfer format, is changed for example,
the TE and RE bits must be cleared to 0 before making the change using the following procedure.
When the TE bit is cleared to 0, the TDRE flag is set to 1. Note that clearing the RE bit to 0 does
not initialize the contents of the RDRF, PER, FER, and ORER flags, or the contents of RDR.
When the external clock is used in asynchronous mode, the clock must be supplied even during
initialization.
SCI Initialization (Asynchronous Mode)
SCR to 1, and set RIE, TIE, TEIE,
(TE and RE bits are cleared to 0.)
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
Set data transfer format in
<Initialization completion>
1-bit interval elapsed?
Set TE and RE bits in
Start initialization
Set value in BRR
SMR and SCMR
and MPIE bits
Figure 13.5 Sample SCI Initialization Flowchart
Yes
Wait
No
[1]
[2]
[3]
[4]
[1] Set the clock selection in SCR.
[2] Set the data transfer format in SMR
[3] Write a value corresponding to the
[4] Wait at least one bit interval, then
Section 13 Serial Communication Interface (SCI)
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.
and SCMR.
bit rate to BRR. Not necessary if
an external clock is used.
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.
Rev. 2.00 Dec. 05, 2005 Page 377 of 724
REJ09B0200-0200