h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 430

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

Section 13 Serial Communication Interface (SCI)
13.6.2
Before transmitting and receiving data, the TE and RE bits in SCR should be cleared to 0, then the
SCI should be initialized as described in a sample flowchart in figure 13.15. 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 change the contents of the RDRF, PER,
FER, and ORER flags, or the contents of RDR.
Rev. 2.00 Dec. 05, 2005 Page 392 of 724
REJ09B0200-0200
Note:* In simultaneous transmit and receive operations, the TE and RE bits should both be cleared
Set TE and RE bits in SCR to 1, and
SCI Initialization (Clocked Synchronous Mode)
set RIE, TIE, TEIE, and MPIE bits
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
to 0 or set to 1 simultaneously.
Set data transfer format in
1-bit interval elapsed?
Start initialization
Set value in BRR
SMR and SCMR
<Transfer start>
(TE, RE bits 0)
Figure 13.15 Sample SCI Initialization Flowchart
Yes
Wait
No
[4]
[2]
[3]
[1]
[1] Set the clock selection in SCR. Be sure
[2] Set the data transfer format in SMR and
[3] Write a value corresponding to the bit
[4] Wait at least one bit interval, then set
to clear bits RIE, TIE, TEIE, and MPIE,
TE and RE, to 0.
SCMR.
rate to BRR. Not necessary if an
external clock is used.
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.