HD64F2638F20J Datasheet, PDF (558/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 13 Serial Communication Interface (SCI)
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
• Reception
Receive operation should be stopped (by clearing RE to 0) before making a module stop mode,
software standby mode, watch mode, subactive mode, or subsleep 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 13-26 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.
[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, watch
mode, subactive mode, and sub-
sleep mode.
Change
operating mode?
Yes
Initialization
No
TE = 1
<Start of transmission>
Figure 13-23 Sample Flowchart for Mode Transition during Transmission
Page 508 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010