h8s-2158 Renesas Electronics Corporation., h8s-2158 Datasheet - Page 476

• Manufacturer Part Number: h8s-2158
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
16.4.5
Before transmitting and receiving data, you should first clear the TE and RE bits in SCR to 0, then
initialize the SCI as shown in figure 16.8. 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. Note that clearing the
RE bit to 0 does not initialize the contents of the RDRF, PER, FER, and ORER flags in SSR, or
the contents of RDR. When the external clock is used in asynchronous mode, the clock must be
supplied even during initialization.
Rev. 3.00 Jan 25, 2006 page 424 of 872
REJ09B0286-0300
SCI Initialization (Asynchronous Mode)
SCR to 1, and set RIE, TIE, TEIE,
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
Set data transfer format in
<Initialization completion>
(TE and RE bits are 0)
1-bit interval elapsed?
Set TE and RE bits in
Set value in BRR
Start initialization
SMR and SCMR
and MPIE bits
Figure 16.8 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
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.