Datasheet

Section 12 Serial Communication Interface
Rev.7.00 Dec. 24, 2008 Page 446 of 698
REJ09B0074-0700
• 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 12.42 shows a sample flowchart for mode transition during reception.
RE = 0
Transition to software
standby mode, etc.
Read receive data in RDR
Read RDRF flag in SSR
Exit from software
standby mode, etc.
Change
operating mode?
No
RDRF = 1
Yes
Yes
<Reception>
No
[1]
[2]
RE = 1Initialization
<Start of reception>
Receive data being received becomes invalid.
Includes module stop mode, watch mode,
subactive mode, and subsleep mode.
[1]
[2]
Figure 12.42 Sample Flowchart for Mode Transition during Reception