HD6432160 RENESAS [Renesas Technology Corp], HD6432160 Datasheet - Page 401

• Manufacturer Part Number: HD6432160
• Description: Hitachi 16-Bit Single-Chip Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

15.4.4
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 15.5. 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 an external clock is used in asynchronous mode, the clock must be
supplied even during initialization.
SCI Initialization (Asynchronous Mode)
Set data transfer/receive format in
SCR to 1, and set RIE, TIE, TEIE,
Clear TE and RE bits in SCR to 0
Set CKE1 and CKE0 bits in SCR
<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 15.5 Sample SCI Initialization Flowchart
Yes
Wait
No
[1]
[2]
[3]
[4]
[1] Set the clock selection in SCR.
[2] Set the data transfer/receive format
[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.
in SMR 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. 2.0, 08/02, page 361 of 788