D12320VF25V Datasheet, PDF (529/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 12 Serial Communication Interface (SCI)
• Reception
Receive operation should be stopped (by clearing RE to 0) before making a module stop mode
or software standby mode transition. RSR, RDR, and SSR are reset. If a transition is made
without stopping operation, the data being received will be invalid.
To continue receiving without changing the reception mode after the relevant mode is cleared,
set RE to 1 before starting reception. To receive with a different receive mode, the procedure
must be started again from initialization.
Figure 12.26 shows a sample flowchart for mode transition during reception.
<Transmission>
All data
transmitted?
Yes
No [1]
Read TEND flag in SSR
TEND = 1
Yes
TE = 0
No
[2]
Transition to software
standby mode, etc.
[3]
Exit from software
standby mode, etc.
Change
No
operating mode?
Yes
Initialization
[1] Data being transmitted is interrupted.
After exiting software standby mode,
etc., normal CPU transmission is
possible by setting TE to 1, reading
SSR, writing TDR, and clearing
TDRE to 0, but note that if the DTC
has been activated, the remaining
data in DTCRAM will be transmitted
when TE and TIE are set to 1.
[2] If TIE and TEIE are set to 1, clear
them to 0 in the same way.
[3] Includes module stop mode.
TE = 1
<Start of transmission>
Figure 12.23 Sample Flowchart for Mode Transition during Transmission
Rev.7.00 Feb. 14, 2007 page 495 of 1108
REJ09B0089-0700