h8s-2111b Renesas Electronics Corporation., h8s-2111b Datasheet - Page 299

• Manufacturer Part Number: h8s-2111b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

12.6.2
Before transmitting and receiving data, you should first clear the TE and RE bits in SCR to 0, then
initialize the SCI as described in a sample flowchart in figure 12.15. When the operating mode,
transfer format, etc., is changed, 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 in SSR is
set to 1. However, clearing the RE bit to 0 does not initialize the RDRF, PER, FER, and ORER
flags in SSR, or RDR.
SCI Initialization (Clocked Synchronous Mode)
Note: * In simultaneous transmit and receive operations, the TE and RE bits should both
Set TE and RE bits in SCR to 1, and
Set data transfer/receive format in
set RIE, TIE, TEIE, and MPIE bits
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
be cleared
(TE and RE bits are 0)
1-bit interval elapsed?
Start initialization
Set value in BRR
SMR and SCMR
<Transfer start>
Figure 12.15 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/receive format in
[3] Write a value corresponding to the bit
[4] Wait at least one bit interval, then set the
to clear bits RIE, TIE, TEIE, and MPIE,
TE and RE to 0.
SMR and SCMR.
rate to BRR. This step is not necessary
if an external clock is used.
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. 1.00, 05/04, page 265 of 544